Alert archive / Wyoming / Winter Storm Warnings in 2017

Winter Storm Warning 8, NWS Riverton, WY

February 20, 20176 counties in Wyoming

NWS Riverton, WY issued this winter storm warning at Feb 20, 2017, 3:15 AM MST for 6 counties in Wyoming. It took effect at Feb 20, 2017, 12:00 PM MST. It was in force for 35 hr. 42 reports came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued
Feb 20, 2017, 3:15 AM MST (10:15 UTC)
In effect from
Feb 20, 2017, 12:00 PM MST
Expired
Feb 21, 2017, 11:07 PM MST
In force
35 hr
Issued by
NWS Riverton, WY

Counties Fremont County, WY, Hot Springs County, WY, Lincoln County, WY, Park County, WY, Sublette County, WY, Teton County, WY

The radar

The Riverton/Lander radar (KRIW), 100 km from the middle of the area, began a volume at 10:20 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

What was reported inside it

TimeReportWhereRemark
Feb 21, 2:28 AM MSTSNOW 314 Ne Pahaska, WYEVENING STAR SNOTEL
Feb 21, 2:28 AM MSTSNOW 319 Wsw Wapiti, WYBLACKWATER SNOTEL
Feb 21, 2:28 AM MSTSNOW 321 W Clark, WYBEARTOOTH LAKE SNOTEL
Feb 21, 2:28 AM MSTSNOW 38 Nne Moran Junction, WYBASE CAMP SNOTEL
Feb 21, 2:28 AM MSTSNOW 411 N Dubois, WYBURROUGHS CREEK SNOTEL
Feb 21, 2:28 AM MSTSNOW 430 Sw Meeteetse, WYKIRWIN SNOTEL
Feb 21, 2:28 AM MSTSNOW 46 Ene Alta, WYGRAND TARGHEE SNOTEL
Feb 21, 2:28 AM MSTSNOW 556 Sw Cody, WYYOUNTS PEAK SNOTEL
Feb 21, 2:28 AM MSTHEAVY SNOW 910 N Bondurant, WYGRANITE CREEK SNOTEL
Feb 21, 2:29 AM MSTSNOW 312 Nne Pinedale, WYELKHART PARK G.S. SNOTEL
Feb 21, 2:29 AM MSTSNOW 38 Wnw Jackson, WYPHILLIPS BENCH SNOTEL
Feb 21, 2:29 AM MSTSNOW 38 W South Entrance, WYGRASSY LAKE SNOTEL
Feb 21, 2:29 AM MSTSNOW 3South Entrance, WYSNAKE RIVER STN SNOTEL
Feb 21, 2:29 AM MSTSNOW 416 Sw Dubois, WYGUNSITE PASS SNOTEL
Feb 21, 2:29 AM MSTSNOW 420 Ne Bondurant, WYGROS VENTRE SUMMIT SNOTEL
Feb 21, 2:29 AM MSTSNOW 522 N Cora, WYKENDALL RANGER STATION SNOTEL
Feb 21, 2:29 AM MSTSNOW 524 Ese Boulder, WYBIG SANDY OPENING SNOTEL
Feb 21, 2:29 AM MSTSNOW 525 Sw Lander, WYLARSEN CREEK SNOTEL
Feb 21, 2:29 AM MSTHEAVY SNOW 614 E Bondurant, WYLOOMIS PARK SNOTEL
Feb 21, 2:29 AM MSTHEAVY SNOW 625 Nw Dubois, WYTOGWOTEE PASS SNOTEL
Feb 21, 2:30 AM MSTSNOW 326 Nw Lander, WYST. LAWRENCE ALT SNOTEL
Feb 21, 2:30 AM MSTSNOW 418 W Lander, WYHOBBS PARK SNOTEL
Feb 21, 2:30 AM MSTSNOW 57 Nw Atlantic City, WYSOUTH PASS SNOTEL
Feb 21, 2:30 AM MSTHEAVY SNOW 619 Sw Bondurant, WYBLIND BULL SUMMIT SNOTEL
Feb 21, 2:30 AM MSTHEAVY SNOW 819 Ssw Lander, WYDEER PARK SNOTEL
Feb 21, 2:31 AM MSTSNOW 315 Nne Cokeville, WYKELLEY RANGER STATION SNOTEL
Feb 21, 2:31 AM MSTSNOW 315 S Afton, WYSALT RIVER SUMMIT SNOTEL
Feb 21, 2:31 AM MSTSNOW 38 Ne Afton, WYWILLOW CREEK SNOTEL
Feb 21, 2:31 AM MSTSNOW 417 E Afton, WYTRIPLE PEAK SNOTEL
Feb 21, 2:31 AM MSTSNOW 421 W Big Piney, WYSNIDER BASIN SNOTEL
Feb 21, 2:31 AM MSTSNOW 519 Se Afton, WYSPRING CREEK DIVIDE SNOTEL
Feb 21, 2:31 AM MSTHEAVY SNOW 636 N Kemmerer, WYINDIAN CREEK SNOTEL
Feb 21, 4:25 AM MSTSNOW 38.6 Nnw Jackson, WYJACKSON HOLE - BASE
Feb 21, 4:25 AM MSTSNOW 5Snow King, WY
Feb 21, 4:25 AM MSTHEAVY SNOW 7Grand Targhee - Chief J, WY
Feb 21, 4:25 AM MSTHEAVY SNOW 99.9 Nnw Jackson, WYJACKSON HOLE - RAYMER
Feb 21, 4:25 AM MSTHEAVY SNOW 11Jackson Hole - Mid Moun, WY
Feb 21, 4:26 AM MSTSNOW 3Togwotee Mountain Lodge, WY
Feb 21, 4:26 AM MSTSNOW 5Commissary Ridge, WY
Feb 21, 4:26 AM MSTHEAVY SNOW 617.2 E Thayne, WYBLIND BULL SUMMIT
Feb 21, 4:26 AM MSTHEAVY SNOW 11Brooks Lake, WY
Feb 21, 11:59 AM MSTHEAVY SNOW 819 Sw Bondurant, WYBLIND BULL SUMMIT SNOTEL

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Riverton, WY (KRIW), launched 00:00Z, 10.3 hours before the alert went out and 106 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Riverton, WY at 00:00Z on 2017-02-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Riverton, WY at 00:00Z on 2017-02-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 26 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1968 m above ground
0-6 km bulk shear
49 kt
0-1 km storm-relative helicity
26 m²/s²
0-3 km storm-relative helicity
26 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

110 
WWUS45 KRIW 201015
WSWRIW

URGENT - WINTER WEATHER MESSAGE
National Weather Service Riverton WY
315 AM MST Mon Feb 20 2017

...A strong Pacific storm will bring heavy snow to the western 
mountains from this Afternoon through Tuesday night...

.A strong Pacific storm will bring heavy snow to the western
mountains from Monday afternoon through Tuesday evening. Also, 
strong west to southwest winds will cause significant blowing and 
drifting snow. The western valleys will see a mix of rain and 
snow.

WYZ001-210000-
/O.UPG.KRIW.WS.A.0011.170221T0000Z-170222T0700Z/
/O.NEW.KRIW.WS.W.0008.170220T1900Z-170222T1200Z/
Yellowstone National Park-
Including the cities of Lake, Mammoth, and Old Faithful
315 AM MST Mon Feb 20 2017

...Winter Storm Warning in effect from noon today to 5 am MST
Wednesday...

The National Weather Service in Riverton has issued a Winter
Storm Warning for snow and blowing snow, which is in effect from 
noon today to 5 AM MST Wednesday. The Winter Storm Watch is no 
longer in effect.

* Timing...Snow and strong winds are expected to move over the
  Yellowstone National Park Monday afternoon and continue through
  Tuesday night.

* Snowfall accumulation...3 to 6 inches in the Mammoth and Tower
  Junction areas. Otherwise 12 to 24 inches of snow are expected,
  with localized amounts up to 30 inches over southwest portion of
  the park.

* Wind and Visibility...West to southwest winds of 20 to 30 mph
  with gusts to 45 mph. Visibility frequently below a quarter mile
  in heavy snow and blowing snow.

* Main Impact...The severely reduced visibility in snow and
  blowing snow can be very disorientating at time for those
  recreating across Yellowstone.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A winter storm warning means significant amounts of snow, and or
blowing snow are expected or occurring. This could make travel
very hazardous or impossible. If you must travel keep some food,
water, and an extra flashlight in your vehicle in case of an
emergency. 

&&

$$

WYZ002-210000-
/O.UPG.KRIW.WS.A.0011.170221T0000Z-170222T0700Z/
/O.NEW.KRIW.WS.W.0008.170220T1900Z-170222T1200Z/
Absaroka Mountains-
315 AM MST Mon Feb 20 2017

...Winter Storm Warning in effect from noon today to 5 am MST
Wednesday...

The National Weather Service in Riverton has issued a Winter
Storm Warning for snow and blowing snow, which is in effect from 
noon today to 5 AM MST Wednesday. The Winter Storm Watch is no 
longer in effect.

* Timing...Snow and strong winds are expected to develop this
  afternoon, and remain through Tuesday Night. 

* Snowfall accumulation...Snowfall of 10 to 20 inches is expected.

* Wind and Visibility...West to southwest winds of 25 to 35 mph
  with gusts to 60 mph especially on mountain passes and upper
  ridges. Visibility will be near zero at times in heavy snow and
  blowing snow.

* Main Impact...Travel may become very difficult with the wind and
  snow producing slick, snow-packed roads and high drifts. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A winter storm warning means significant amounts of snow, and or
blowing snow are expected or occurring. This could make travel
very hazardous or impossible. If you must travel keep some food,
water, and an extra flashlight in your vehicle in case of an
emergency. Check the latest road conditions at wyoroad.info or by
dialing 5 1 1.

&&

$$

WYZ012-024-210000-
/O.UPG.KRIW.WS.A.0011.170221T0000Z-170222T0700Z/
/O.NEW.KRIW.WS.W.0008.170220T1900Z-170222T1200Z/
Teton and Gros Ventre Mountains-Salt River and Wyoming Ranges-
315 AM MST Mon Feb 20 2017

...Winter Storm Warning in effect from noon today to 5 am MST
Wednesday...

The National Weather Service in Riverton has issued a Winter
Storm Warning for snow and blowing snow, which is in effect from 
noon today to 5 AM MST Wednesday. The Winter Storm Watch is no 
longer in effect.

* Timing...Snow and strong winds are expected to move into the
  western mountains of Wyoming Monday afternoon. Snow and wind are
  expected to continue through Tuesday night.

* Snowfall Accumulation...12 to 24 inches are expected, with
  localized amounts up to 30 inches in the Teton mountains.

* Wind and Visibility...West to southwest winds of 25 to 35 mph
  with gusts to 60 mph...especially in open areas or mountain
  summits. Visibility frequently below a quarter mile in heavy
  snow and blowing snow.

* Main Impact...Travel will become very difficult with the wind
  and snow producing slick, snow-packed roads along with high
  drifts over mountain passes. Please monitor JHAVALANCHE.ORG if
  your plans include travel into the backcountry. Also, the
  severely reduced visibility will be very disorientating for
  those recreating in the backcountry.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A winter storm warning means significant amounts of snow, and or
blowing snow are expected or occurring. This could make travel
very hazardous or impossible. If you must travel keep some food,
water, and an extra flashlight in your vehicle in case of an
emergency. Check the latest road conditions at wyoroad.info or by
dialing 5 1 1.

&&

$$

WYZ014-210000-
/O.UPG.KRIW.WS.A.0011.170221T0000Z-170222T0700Z/
/O.NEW.KRIW.WS.W.0008.170220T1900Z-170222T1200Z/
Wind River Mountains West-
315 AM MST Mon Feb 20 2017

...Winter Storm Warning in effect from noon today to 5 am MST
Wednesday...

The National Weather Service in Riverton has issued a Winter
Storm Warning for snow and blowing snow, which is in effect from 
noon today to 5 AM MST Wednesday. The Winter Storm Watch is no 
longer in effect.

* Timing...Snow and strong winds are expected to move into the
  western mountains of Wyoming Monday afternoon. Snow and wind are
  expected to continue through Tuesday night.

* Snowfall Accumulation...5 to 10 inches over South Pass. 12 to 24
  inches over the rest of the Wind River Mountains with the
  highest amounts over the western slopes.

* Wind and Visibility...West to southwest winds of 20 to 30 mph
  with gusts to 45 mph on the upper ridges. Visibility frequently
  below a quarter mile in heavy snow and blowing snow. 

* Main Impact...Travel may become very difficult or impossible
  across South Pass due to the wind and snow producing slick,
  snow-packed roads along with high drifts.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A winter storm warning means significant amounts of snow, and or
blowing snow are expected or occurring. This could make travel
very hazardous or impossible. If you must travel keep some food,
water, and an extra flashlight in your vehicle in case of an
emergency. Check the latest road conditions at wyoroad.info or by
dialing 5 1 1.

&&

$$

WYZ015-210000-
/O.NEW.KRIW.WS.W.0008.170220T1900Z-170222T1200Z/
Wind River Mountains East-
315 AM MST Mon Feb 20 2017

...Winter Storm Warning in effect from noon today to 5 am MST
Wednesday...

The National Weather Service in Riverton has issued a Winter
Storm Warning for snow and blowing snow , which is in effect from
noon today to 5 AM MST Wednesday. 

* Timing...Snow and strong winds are expected to move into the
  western mountains of Wyoming Monday afternoon. Snow and wind are
  expected to continue through Tuesday night.

* Snowfall Accumulation...5 to 10 inches over South Pass. 12 to 24
  inches over the rest of the Wind River Mountains with the
  highest amounts over the western slopes.

* Wind and Visibility...West to southwest winds of 30 to 40 mph
  with gusts of 60. Wind gusts of 70 mph are expected over South
  Pass Monday afternoon through early Tuesday morning. Near
  whiteout conditions could occur at times in heavy snow and, or
  blowing snow.

* Main Impact...Travel may become very difficult or impossible
  across South Pass due to the wind and snow producing slick,
  snow-packed roads along with high drifts.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A winter storm warning means significant amounts of snow, and or
blowing snow are expected or occurring. This could make travel
very hazardous or impossible. If you must travel keep some food,
water, and an extra flashlight in your vehicle in case of an
emergency. Check the latest road conditions at wyoroad.info or by
dialing 5 1 1.

&&

$$
5 follow-up statements
739 
WWUS45 KRIW 202015
WSWRIW

URGENT - WINTER WEATHER MESSAGE
National Weather Service Riverton WY
115 PM MST Mon Feb 20 2017

...A strong Pacific storm will bring heavy snow to the western
mountains from this Afternoon through Tuesday night...

.Southwest flow aloft with a deep pineapple connection moisture 
plume entering western Wyoming will continue to produce periods of
moderate to heavy snow with strong winds at ridge top and pass 
level. Prolonged periods of 2 inch an hour snowfall is expected. 
Temperatures will cool Tuesday night with a gradual decrease in 
snowfall into Wednesday morning. Winter storm warning will remain 
in effect until early wednesday morning. Tetons still look good 
for a 30 inch snowfall while the rest of the western mountains 
should be in the 15 to 25 inch range. Valleys still look warm 
enough for mainly rain to rain snow mix until Tuesday evening when
temperatures cool and precipitation should change over to snow 
for the last 12 hours of the storm. Some light snow will continue 
with low accumulations Wednesday and Wednesday night with much 
colder temperatures. 

WYZ001-211000-
/O.CON.KRIW.WS.W.0008.000000T0000Z-170222T1200Z/
Yellowstone National Park-
Including the cities of Lake, Mammoth, and Old Faithful
115 PM MST Mon Feb 20 2017

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 5 AM MST
WEDNESDAY...

* Timing...Snow and strong winds are expected to move over the
  Yellowstone National Park and continue through Tuesday night.


* Snowfall accumulation...3 to 6 inches in the Mammoth and Tower
  Junction areas. Otherwise 15 to 25 inches of snow are expected,
  with localized amounts up to 30 inches over southwest portion 
  of the park. 

* Wind and Visibility...West to southwest winds of 20 to 30 mph 
  with gusts to 45 mph. Visibility frequently below a quarter 
  mile in heavy snow and blowing snow. 

* Main Impact...The severely reduced visibility in snow and 
  blowing snow can be very disorientating at time for those 
  recreating across Yellowstone. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A winter storm warning means significant amounts of snow, and or
blowing snow are expected or occurring. This could make travel
very hazardous or impossible. If you must travel keep some food,
water, and an extra flashlight in your vehicle in case of an
emergency.

&&

$$

WYZ002-211000-
/O.CON.KRIW.WS.W.0008.000000T0000Z-170222T1200Z/
Absaroka Mountains-
115 PM MST Mon Feb 20 2017

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 5 AM MST
WEDNESDAY...

* Timing...Snow and strong winds are expected to develop this 
  afternoon, and remain through Tuesday Night. 

* Snowfall accumulation...Snowfall of 10 to 20 inches is 
  expected.

* Wind and Visibility...West to southwest winds of 25 to 35 mph 
  with gusts to 60 mph especially on mountain passes and upper 
  ridges. Visibility will be near zero at times in heavy snow 
  and blowing snow. 

* Main Impact...Travel may become very difficult with the wind 
  and snow producing slick, snow-packed roads and high drifts. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A winter storm warning means significant amounts of snow, and or
blowing snow are expected or occurring. This could make travel
very hazardous or impossible. If you must travel keep some food,
water, and an extra flashlight in your vehicle in case of an
emergency. Check the latest road conditions at wyoroad.info or by
dialing 5 1 1.

&&

$$

WYZ012-024-211000-
/O.CON.KRIW.WS.W.0008.000000T0000Z-170222T1200Z/
Teton and Gros Ventre Mountains-Salt River and Wyoming Ranges-
115 PM MST Mon Feb 20 2017

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 5 AM MST
WEDNESDAY...

* Timing...Snow and strong winds have moved into the Teton and
  Gros Ventre mountains of Wyoming. Snow and wind are expected to
  continue through Tuesday night. 

* Snowfall Accumulation...15 to 25 inches are expected, with 
  amounts up to 30 inches in the Teton mountains. 

* Wind and Visibility...West to southwest winds of 25 to 35 mph 
  with gusts to 60 mph...especially in open areas or mountain 
  summits. Visibility frequently below a quarter mile in heavy 
  snow and blowing snow. 

* Main Impact...Travel will become very difficult with the wind 
  and snow producing slick, snow-packed roads along with high 
  drifts over mountain passes. Please monitor JHAVALANCHE.ORG if 
  your plans include travel into the backcountry. Also, the 
  severely reduced visibility will be very disorientating for 
  those recreating in the backcountry. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A winter storm warning means significant amounts of snow, and or
blowing snow are expected or occurring. This could make travel
very hazardous or impossible. If you must travel keep some food,
water, and an extra flashlight in your vehicle in case of an
emergency. Check the latest road conditions at wyoroad.info or by
dialing 5 1 1.

&&

$$

WYZ014-015-211000-
/O.CON.KRIW.WS.W.0008.000000T0000Z-170222T1200Z/
Wind River Mountains West-Wind River Mountains East-
115 PM MST Mon Feb 20 2017

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 5 AM MST
WEDNESDAY...

* Timing...Snow and strong winds have moved into the Wind River
  mountains of Wyoming. Snow and wind are expected to continue
 through Tuesday night. 

* Snowfall Accumulation...8 to 16 inches over South Pass. 12 to 24
  inches over the rest of the Wind River Mountains with the
  highest amounts over the western slopes. 

* Wind and Visibility...West to southwest winds of 25 to 35 mph
  with gusts to 45 mph, gusts to 65 mph on South Pass. Visibility
  frequently below a quarter mile in heavy snow and blowing snow.


* Main Impact...Travel may become very difficult or impossible 
  across South Pass due to the wind and snow producing slick, 
  snow-packed roads along with high drifts. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A winter storm warning means significant amounts of snow, and or
blowing snow are expected or occurring. This could make travel
very hazardous or impossible. If you must travel keep some food,
water, and an extra flashlight in your vehicle in case of an
emergency. Check the latest road conditions at wyoroad.info or by
dialing 5 1 1.

&&

$$
361 
WWUS45 KRIW 210222
WSWRIW

URGENT - WINTER WEATHER MESSAGE
National Weather Service Riverton WY
722 PM MST Mon Feb 20 2017

...A strong Pacific storm will bring heavy snow to the western
mountains through Tuesday night...

.Southwest flow aloft with a deep pineapple connection moisture
plume entering western Wyoming will continue to produce periods
of moderate to heavy snow with strong winds at ridge top and pass
level. Prolonged periods of 2 inch an hour snowfall is expected.
Temperatures will cool Tuesday night with a gradual decrease in
snowfall into Wednesday morning. Valleys still look warm enough 
for mainly rain or a rain and snow mix until Tuesday evening when
temperatures cool and precipitation should change over to snow 
for the last 12 hours of the storm. Some light snow will continue 
with low accumulations Wednesday and Wednesday night with much 
colder temperatures.

WYZ001-211100-
/O.CON.KRIW.WS.W.0008.000000T0000Z-170222T1200Z/
Yellowstone National Park-
Including the cities of Lake, Mammoth, and Old Faithful
722 PM MST Mon Feb 20 2017

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 5 AM MST
WEDNESDAY...

* Timing...Snow and windy areas are expected to occur move over 
  the Yellowstone National Park and continue through Tuesday 
  night. 

* Snowfall accumulation...3 to 6 inches in the Mammoth and Tower 
  Junction areas. Otherwise 15 to 25 inches of snow are 
  expected, with localized amounts up to 30 inches over 
  southwest portion of the park. 

* Wind and Visibility...West to southwest winds of 20 to 30 mph 
  with gusts to 45 mph. Visibility frequently below a quarter 
  mile in heavy snow and blowing snow. 

* Main Impact...The severely reduced visibility in snow and 
  blowing snow can be very disorientating at time for those 
  recreating across Yellowstone. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A winter storm warning means significant amounts of snow, and or
blowing snow are expected or occurring. This could make travel
very hazardous or impossible. If you must travel keep some food,
water, and an extra flashlight in your vehicle in case of an
emergency.

&&

$$

WYZ002-211100-
/O.CON.KRIW.WS.W.0008.000000T0000Z-170222T1200Z/
Absaroka Mountains-
722 PM MST Mon Feb 20 2017

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 5 AM MST
WEDNESDAY...

* Timing...Snow and strong winds are expected to occur through 
  Tuesday Night. 

* Snowfall accumulation...Snowfall of 10 to 20 inches is 
  expected. 

* Wind and Visibility...West to southwest winds of 25 to 35 mph 
  with gusts to 60 mph especially on mountain passes and upper 
  ridges. Visibility will be near zero at times in heavy snow 
  and blowing snow. 

* Main Impact...Travel may become very difficult with the wind 
  and snow producing slick, snow-packed roads and high drifts. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A winter storm warning means significant amounts of snow, and or
blowing snow are expected or occurring. This could make travel
very hazardous or impossible. If you must travel keep some food,
water, and an extra flashlight in your vehicle in case of an
emergency. Check the latest road conditions at wyoroad.info or by
dialing 5 1 1.

&&

$$

WYZ012-024-211100-
/O.CON.KRIW.WS.W.0008.000000T0000Z-170222T1200Z/
Teton and Gros Ventre Mountains-Salt River and Wyoming Ranges-
722 PM MST Mon Feb 20 2017

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 5 AM MST
WEDNESDAY...

* Timing...Snow and areas of strong wind will occur through 
  Tuesday night. 

* Snowfall Accumulation...15 to 25 inches are expected, with 
  amounts up to 30 inches in the Teton mountains. 

* Wind and Visibility...West to southwest winds of 25 to 35 mph 
  with gusts to 60 mph...especially in open areas or mountain 
  summits. Visibility frequently below a quarter mile in heavy 
  snow and blowing snow. 

* Main Impact...Travel will become very difficult with the wind 
  and snow producing slick, snow-packed roads along with high 
  drifts over mountain passes. Please monitor JHAVALANCHE.ORG if 
  your plans include travel into the backcountry. Also, the 
  severely reduced visibility will be very disorientating for 
  those recreating in the backcountry. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A winter storm warning means significant amounts of snow, and or
blowing snow are expected or occurring. This could make travel
very hazardous or impossible. If you must travel keep some food,
water, and an extra flashlight in your vehicle in case of an
emergency. Check the latest road conditions at wyoroad.info or by
dialing 5 1 1.

&&

$$

WYZ014-015-211100-
/O.CON.KRIW.WS.W.0008.000000T0000Z-170222T1200Z/
Wind River Mountains West-Wind River Mountains East-
722 PM MST Mon Feb 20 2017

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 5 AM MST
WEDNESDAY...

* Timing...Snow and strong winds will occur through Tuesday 
  night. 

* Snowfall Accumulation...8 to 16 inches over South Pass. 12 to 
  24 inches over the rest of the Wind River Mountains with the 
  highest amounts over the western slopes. 

* Wind and Visibility...West to southwest winds of 25 to 35 mph 
  with gusts to 45 mph, gusts to 65 mph on South Pass. 
  Visibility frequently below a quarter mile in heavy snow and 
  blowing snow. 

* Main Impact...Travel may become very difficult or impossible 
  across South Pass due to the wind and snow producing slick, 
  snow-packed roads along with high drifts. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A winter storm warning means significant amounts of snow, and or
blowing snow are expected or occurring. This could make travel
very hazardous or impossible. If you must travel keep some food,
water, and an extra flashlight in your vehicle in case of an
emergency. Check the latest road conditions at wyoroad.info or by
dialing 5 1 1.

&&

$$
966 
WWUS45 KRIW 210928
WSWRIW

URGENT - WINTER WEATHER MESSAGE
National Weather Service Riverton WY
228 AM MST Tue Feb 21 2017

...Heavy snow will continue to fall over the western mountains 
through tonight...

.Southwest flow aloft with a deep moisture plume will continue to
produce periods of moderate to heavy snow with strong winds at 
ridge top and pass level. Prolonged periods of 2 inch an hour 
snowfall is expected. Valleys will stay warm enough for mainly 
rain or a rain/snow mix until this evening, when temperatures 
cool as a cold front quickly moves through the area. Precipitation
will then change over to snow through the overnight hours 
tonight. Some light snow will continue with low accumulations 
Wednesday and Wednesday night with much colder temperatures.

WYZ001-212300-
/O.CON.KRIW.WS.W.0008.000000T0000Z-170222T1200Z/
Yellowstone National Park-
Including the cities of Lake, Mammoth, and Old Faithful
228 AM MST Tue Feb 21 2017

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 5 AM MST
WEDNESDAY...

* Timing...Snow and windy areas will continue over Yellowstone
  National Park and continue through tonight.

* Snowfall accumulation...3 to 6 inches in the Mammoth and Tower 
  Junction areas. Otherwise 15 to 25 inches of snow are 
  expected, with localized amounts up to 30 inches over 
  southwest portions of the park. 

* Wind and Visibility...West to southwest winds of 20 to 30 mph 
  with gusts to 45 mph. Visibility frequently below a quarter 
  mile in heavy snow and blowing snow. 

* Main Impact...The severely reduced visibility in snow and 
  blowing snow can be very disorientating at time for those 
  recreating across Yellowstone. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A winter storm warning means significant amounts of snow, and or
blowing snow are expected or occurring. This could make travel
very hazardous or impossible. If you must travel keep some food,
water, and an extra flashlight in your vehicle in case of an
emergency.

&&

$$

WYZ002-212300-
/O.CON.KRIW.WS.W.0008.000000T0000Z-170222T1200Z/
Absaroka Mountains-
228 AM MST Tue Feb 21 2017

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 5 AM MST
WEDNESDAY...

* Timing...Snow and strong winds will continue through tonight.


* Snowfall accumulation...Snowfall of 10 to 20 inches.

* Wind and Visibility...West to southwest winds of 25 to 35 mph 
  with gusts to 60 mph, especially on mountain passes and upper 
  ridges. Visibility will be near zero at times in heavy snow 
  and blowing snow. 

* Main Impact...Travel may become very difficult with the wind 
  and snow producing slick, snow-packed roads and high drifts. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A winter storm warning means significant amounts of snow, and or
blowing snow are expected or occurring. This could make travel
very hazardous or impossible. If you must travel keep some food,
water, and an extra flashlight in your vehicle in case of an
emergency. Check the latest road conditions at wyoroad.info or by
dialing 5 1 1.

&&

$$

WYZ012-024-212300-
/O.CON.KRIW.WS.W.0008.000000T0000Z-170222T1200Z/
Teton and Gros Ventre Mountains-Salt River and Wyoming Ranges-
228 AM MST Tue Feb 21 2017

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 5 AM MST
WEDNESDAY...

* Timing...Snow and areas of strong wind will occur through
  tonight.

* Snowfall Accumulation...15 to 25 inches are expected, with 
  amounts up to 30 inches in the Teton mountains. 

* Wind and Visibility...West to southwest winds of 25 to 35 mph 
  with gusts to 60 mph...especially in open areas or mountain 
  summits. Visibility frequently below a quarter mile in heavy 
  snow and blowing snow. 

* Main Impact...Travel will become very difficult with the wind 
  and snow producing slick, snow-packed roads along with high 
  drifts over mountain passes. Please monitor JHAVALANCHE.ORG if 
  your plans include travel into the backcountry. Also, the 
  severely reduced visibility will be very disorientating for 
  those recreating in the backcountry. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A winter storm warning means significant amounts of snow, and or
blowing snow are expected or occurring. This could make travel
very hazardous or impossible. If you must travel keep some food,
water, and an extra flashlight in your vehicle in case of an
emergency. Check the latest road conditions at wyoroad.info or by
dialing 5 1 1.

&&

$$

WYZ014-015-212300-
/O.CON.KRIW.WS.W.0008.000000T0000Z-170222T1200Z/
Wind River Mountains West-Wind River Mountains East-
228 AM MST Tue Feb 21 2017

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 5 AM MST
WEDNESDAY...

* Timing...Snow and strong winds will continue through tonight.

* Snowfall Accumulation...8 to 16 inches over South Pass. 12 to 
  24 inches over the rest of the Wind River Mountains with the 
  highest amounts over the western slopes. 

* Wind and Visibility...West to southwest winds of 25 to 35 mph 
  with gusts to 45 mph, gusts to 65 mph on South Pass. 
  Visibility frequently below a quarter mile in heavy snow and 
  blowing snow. 

* Main Impact...Travel may become very difficult or impossible 
  across South Pass due to the wind and snow producing slick, 
  snow-packed roads along with high drifts. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A winter storm warning means significant amounts of snow, and or
blowing snow are expected or occurring. This could make travel
very hazardous or impossible. If you must travel keep some food,
water, and an extra flashlight in your vehicle in case of an
emergency. Check the latest road conditions at wyoroad.info or by
dialing 5 1 1.

&&

$$
162 
WWUS45 KRIW 212248
WSWRIW

URGENT - WINTER WEATHER MESSAGE
National Weather Service Riverton WY
348 PM MST Tue Feb 21 2017

...Heavy snow will continue to fall over the western mountains
through tonight...

...Heavy snow may impact Central and Southern Wyoming for Late 
Wednesday night through mid day Friday...

.Southwest flow aloft with a deep moisture plume will continue to
produce periods of moderate to heavy snow with strong winds at
ridge top and pass level tonight although the snowfall intensity
and strong winds will gradually diminish tonight. Snow will
continue in the Jackson Valley but will only accumulate around 1
to 2 inches this evening. The Star Valley will have rain turning 
to snow by 4 pm this afternoon. Some light snow will continue with
low accumulations Wednesday and Wednesday night with much colder 
temperatures.

A separate strong winter storm will deliver a heavy dose of
snowfall to much of Central and Southern Wyoming, east of the
Divide, by late Wednesday night and continue through mid day 
Friday. The heaviest snowfall should occur between 2 am Wednesday
night through 11 am Thursday. As much as 2 feet of snow could
accumulate on Casper Mountain by Friday with as much much as a
foot and a half in the Casper area. 6 to 10 inches could fall over
much of the rest of the area. In addition, strong northeast winds
may result in considerable blowing and drifting snow, especially 
around the Casper area. 


WYZ014-015-221100-
/O.NEW.KRIW.WS.A.0012.170223T0600Z-170224T1800Z/
/O.CON.KRIW.WS.W.0008.000000T0000Z-170222T1200Z/
Wind River Mountains West-Wind River Mountains East-
348 PM MST Tue Feb 21 2017

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 5 AM MST
WEDNESDAY...
...WINTER STORM WATCH IN EFFECT FROM WEDNESDAY EVENING THROUGH
FRIDAY MORNING...

The National Weather Service in Riverton has issued a Winter
Storm Watch, which is in effect from Wednesday evening through
Friday morning. 

* Timing...Snow and strong winds will continue through tonight but
  will gradually diminish in intensity. Snow is expected to
  redevelop late Wednesday night and continue through mid day
  Friday, heavy at times.

* Snowfall Accumulation...5 to 7 inches have fallen so far except
  close to a foot has fallen over the northern portion of the
  range. 8 to 16 inches expected over South Pass. 12 to 24 inches
  over the rest of the Wind River Mountains with the highest 
  amounts over the western slopes. 

* Wind and Visibility...West to southwest winds of 25 to 35 mph 
  with gusts to 45 mph, gusts to 65 mph on South Pass. 
  Visibility frequently below a quarter mile in heavy snow and 
  blowing snow. 

* Main Impact...Travel may become very difficult or impossible 
  across South Pass due to the wind and snow producing slick, 
  snow-packed roads along with high drifts. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A winter storm warning means significant amounts of snow, and or
blowing snow are expected or occurring. This could make travel
very hazardous or impossible. If you must travel keep some food,
water, and an extra flashlight in your vehicle in case of an
emergency. Check the latest road conditions at wyoroad.info or by
dialing 5 1 1.

A winter storm watch means there is a potential for significant
snow and/or blowing snow that may impact travel. Continue to
monitor the latest forecasts.

&&

$$

WYZ001-221100-
/O.CON.KRIW.WS.W.0008.000000T0000Z-170222T1200Z/
Yellowstone National Park-
Including the cities of Lake, Mammoth, and Old Faithful
348 PM MST Tue Feb 21 2017

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 5 AM MST
WEDNESDAY...

* Timing...Snow and windy areas will continue over Yellowstone
  National Park and continue through tonight but the intensity
  will gradually  during the night tonight.

* Snowfall accumulation...5 to 10 inches have fallen over portions
  of the park. 3 to 6 inches expected in the Mammoth and Tower
  Junction areas. Otherwise 15 to 25 inches of snow are expected,
  with localized amounts up to 30 inches over southwest portions 
  of the park. 

* Wind and Visibility...West to southwest winds of 20 to 30 mph 
  with gusts to 45 mph. Visibility frequently below a quarter 
  mile in heavy snow and blowing snow. 

* Main Impact...The severely reduced visibility in snow and 
  blowing snow can be very disorientating at time for those 
  recreating across Yellowstone. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A winter storm warning means significant amounts of snow, and or
blowing snow are expected or occurring. This could make travel
very hazardous or impossible. If you must travel keep some food,
water, and an extra flashlight in your vehicle in case of an
emergency.

&&

$$

WYZ002-221100-
/O.CON.KRIW.WS.W.0008.000000T0000Z-170222T1200Z/
Absaroka Mountains-
348 PM MST Tue Feb 21 2017

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 5 AM MST
WEDNESDAY...

* Timing...Snow and strong winds will continue through tonight but
  will gradually diminish.

* Snowfall accumulation...5 to 10 inches have fallen so far.
  Snowfall of 10 to 20 inches expected.

* Wind and Visibility...West to southwest winds of 25 to 35 mph 
  with gusts to 60 mph, especially on mountain passes and upper 
  ridges. Visibility will be near zero at times in heavy snow 
  and blowing snow. 

* Main Impact...Travel may become very difficult with the wind 
  and snow producing slick, snow-packed roads and high drifts. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A winter storm warning means significant amounts of snow, and or
blowing snow are expected or occurring. This could make travel
very hazardous or impossible. If you must travel keep some food,
water, and an extra flashlight in your vehicle in case of an
emergency. Check the latest road conditions at wyoroad.info or by
dialing 5 1 1.

&&

$$

WYZ012-024-221100-
/O.CON.KRIW.WS.W.0008.000000T0000Z-170222T1200Z/
Teton and Gros Ventre Mountains-Salt River and Wyoming Ranges-
348 PM MST Tue Feb 21 2017

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 5 AM MST
WEDNESDAY...

* Timing...Snow and areas of strong wind will occur through 
  tonight. 

* Snowfall Accumulation...4 to 8 inches have fallen over portions
  of the area with over a foot at the top of Rendezvous Peak.. 15
  to 25 inches are expected, with amounts up to 30 inches in the 
  Teton mountains. 

* Wind and Visibility...West to southwest winds of 25 to 35 mph 
  with gusts to 60 mph...especially in open areas or mountain 
  summits. Visibility frequently below a quarter mile in heavy 
  snow and blowing snow. 

* Main Impact...Travel will become very difficult with the wind 
  and snow producing slick, snow-packed roads along with high 
  drifts over mountain passes. Please monitor JHAVALANCHE.ORG if 
  your plans include travel into the backcountry. Also, the 
  severely reduced visibility will be very disorientating for 
  those recreating in the backcountry. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A winter storm warning means significant amounts of snow, and or
blowing snow are expected or occurring. This could make travel
very hazardous or impossible. If you must travel keep some food,
water, and an extra flashlight in your vehicle in case of an
emergency. Check the latest road conditions at wyoroad.info or by
dialing 5 1 1.

&&

$$

WYZ020-022-221100-
/O.NEW.KRIW.WS.A.0012.170223T0600Z-170224T1800Z/
Natrona County Lower Elevations-Casper Mountain-
Including the city of Casper
348 PM MST Tue Feb 21 2017

...WINTER STORM WATCH IN EFFECT FROM WEDNESDAY EVENING THROUGH
FRIDAY MORNING...

The National Weather Service in Riverton has issued a Winter
Storm Watch, which is in effect from Wednesday evening through
Friday morning. 

* TIMING...Snow will develop Wednesday night and may become heavy
at times after 2 am. Snow heavy at times will continue through 
the day Thursday, Thursday night and through mid day Friday. The
heaviest snowfall will likely occur between 2 am Wednesday 
night through 11 am Thursday morning. 

* SNOWFALL ACCUMULATION...Ranging from up to 2 feet on Casper
  Mountain, up to a foot and a half in the vicinity of the city of
  Casper and 9 to 12 inches across Northern and Western Natrona 
  County

* MAIN IMPACT...Roads may become slick and snow covered.
  Considerable blowing and drifting snow could make travel
  difficult to impossible. The visibility may become significantly
  reduced in blowing snow.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A winter storm watch means there is a potential for significant
snow and/or blowing snow that may impact travel. Continue to
monitor the latest forecasts.

&&

$$

WYZ019-221100-
/O.NEW.KRIW.WS.A.0012.170223T0600Z-170224T1800Z/
Green Mountains and Rattlesnake Range-
Including the city of Jeffrey City
348 PM MST Tue Feb 21 2017

...WINTER STORM WATCH IN EFFECT FROM WEDNESDAY EVENING THROUGH
FRIDAY MORNING...

The National Weather Service in Riverton has issued a Winter
Storm Watch, which is in effect from Wednesday evening through
Friday morning. 

* TIMING...Snow will develop Wednesday night and may become heavy
at times after 2 am. Snow heavy at times will continue through 
the day Thursday, Thursday night and through mid day Friday. The
heaviest snowfall will likely occur between 2 am Wednesday 
night through 11 am Thursday morning. 

* SNOWFALL ACCUMULATION...10 to 16 inches.

* MAIN IMPACT...Roads may become slick and snow covered. Blowing 
and drifting snow could make travel rather difficult. Blowing 
snow may significantly reduce visibility.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A winter storm watch means there is a potential for significant
snow and/or blowing snow that may impact travel. Continue to
monitor the latest forecasts.

&&

$$

WYZ030-221100-
/O.NEW.KRIW.WS.A.0012.170223T0600Z-170224T1800Z/
East Sweetwater County-
Including the city of Wamsutter
348 PM MST Tue Feb 21 2017

...WINTER STORM WATCH IN EFFECT FROM WEDNESDAY EVENING THROUGH
FRIDAY MORNING...

The National Weather Service in Riverton has issued a Winter
Storm Watch, which is in effect from Wednesday evening through
Friday morning. 

* TIMING...Snow will develop Wednesday night and may become heavy
at times after 2 am. Snow heavy at times will continue through 
the day Thursday, Thursday night and through mid day Friday. The
heaviest snowfall will likely occur between 2 am Wednesday 
night through 11 am Thursday morning. 

* SNOWFALL ACCUMULATION...Ranging from 5 to 8 inches in Central
  Sweetwater County to up to 15 inches in Eastern SweeterCounty.

* MAIN IMPACT...Roads may become slick and snow covered. Blowing
  and drifting snow could make travel rather difficult. Blowing
  snow may significantly reduce visibility.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A winter storm watch means there is a potential for significant
snow and/or blowing snow that may impact travel. Continue to
monitor the latest forecasts.

&&

$$

WYZ017-018-221100-
/O.NEW.KRIW.WS.A.0012.170223T0600Z-170224T1800Z/
Wind River Basin-Lander Foothills-
Including the cities of Riverton, Shoshoni, and Lander
348 PM MST Tue Feb 21 2017

...WINTER STORM WATCH IN EFFECT FROM WEDNESDAY EVENING THROUGH
FRIDAY MORNING...

The National Weather Service in Riverton has issued a Winter
Storm Watch, which is in effect from Wednesday evening through
Friday morning. 

* TIMING...Snow will develop Wednesday night and may become heavy
at times after 2 am. Snow heavy at times will continue through 
the day Thursday, Thursday night and through mid day Friday. The
heaviest snowfall will likely occur between 2 am Wednesday 
night through 11 am Thursday morning. 

* SNOWFALL ACCUMULATION...10 to 13 inches in Eastern Fremont
  County, 6 to 10 inches in the Riverton lander area, and 3 to 5
  inches around Kinnear and Pavillion.

* MAIN IMPACT...Roads may become slick and snow covered. Blowing
  and drifting snow could make travel rather difficult. Blowing
  snow may significantly reduce visibility.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A winter storm watch means there is a potential for significant
snow and/or blowing snow that may impact travel. Continue to
monitor the latest forecasts.

&&

$$

WYZ007-221100-
/O.NEW.KRIW.WS.A.0012.170223T0600Z-170224T1800Z/
Owl Creek and Bridger Mountains-
348 PM MST Tue Feb 21 2017

...WINTER STORM WATCH IN EFFECT FROM WEDNESDAY EVENING THROUGH
FRIDAY MORNING...

The National Weather Service in Riverton has issued a Winter
Storm Watch, which is in effect from Wednesday evening through
Friday morning. 

* TIMING...Snow will develop Wednesday night and may become heavy
at times after 2 am. Snow heavy at times will continue through 
the day Thursday, Thursday night and through mid day Friday. The
heaviest snowfall will likely occur between 2 am Wednesday 
night through 11 am Thursday morning. 

* SNOWFALL ACCUMULATION...6 top 10 inches.

* MAIN IMPACT...Roads may become slick and snow covered. Blowing
  and drifting snow could make travel rather difficult including
  travel through the Wind River Canyon. Blowing snow may
  significantly reduce visibility, especially at the southern end
  of the Wind River Canyon.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A winter storm watch means there is a potential for significant
snow and/or blowing snow that may impact travel. Continue to
monitor the latest forecasts.

&&

$$

WYZ011-221100-
/O.NEW.KRIW.WS.A.0012.170223T0600Z-170224T1800Z/
Southeast Johnson County-
Including the city of Kaycee
348 PM MST Tue Feb 21 2017

...WINTER STORM WATCH IN EFFECT FROM WEDNESDAY EVENING THROUGH
FRIDAY MORNING...

The National Weather Service in Riverton has issued a Winter
Storm Watch, which is in effect from Wednesday evening through
Friday morning. 

* TIMING...Snow will develop Wednesday night and may become heavy
at times after 2 am. Snow heavy at times will continue through 
the day Thursday, Thursday night and through mid day Friday. The
heaviest snowfall will likely occur between 2 am Wednesday 
night through 11 am Thursday morning. 

* SNOWFALL ACCUMULATION...6 to 10 inches with the heaviest
  snowfall expected near the Natrona County line.

* MAIN IMPACT...Roads may become slick and snow covered. Blowing
  and drifting snow could make travel rather difficult. Blowing
  snow may significantly reduce visibility.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A winter storm watch means there is a potential for significant
snow and/or blowing snow that may impact travel. Continue to
monitor the latest forecasts.

&&

$$

TEAM RIVERTON
089 
WWUS45 KRIW 220607
WSWRIW

URGENT - WINTER WEATHER MESSAGE
National Weather Service Riverton WY
1107 PM MST Tue Feb 21 2017

...Heavy snow may impact Central and Southern Wyoming for Late 
Wednesday night through mid day Friday...

.Southwest flow aloft with a deep moisture plume will continue to
produce periods of moderate to heavy snow with strong winds at
ridge top and pass level tonight although the snowfall intensity
and strong winds will gradually diminish tonight. Snow will
continue in the Jackson Valley but will only accumulate around
1 to 2 inches this evening. The Star Valley will have rain
turning to snow by 4 pm this afternoon. Some light snow will
continue with low accumulations Wednesday and Wednesday night
with much colder temperatures.

A separate strong winter storm will deliver a heavy dose of
snowfall to much of Central and Southern Wyoming, east of the
Divide, by late Wednesday night and continue through mid day
Friday. The heaviest snowfall should occur between 2 am Wednesday
night through 11 am Thursday. As much as 2 feet of snow could
accumulate on Casper Mountain by Friday with as much much as a
foot and a half in the Casper area. 6 to 10 inches could fall
over much of the rest of the area. In addition, strong northeast
winds may result in considerable blowing and drifting snow,
especially around the Casper area.

WYZ014-015-222200-
/O.CAN.KRIW.WS.W.0008.000000T0000Z-170222T1200Z/
/O.CON.KRIW.WS.A.0012.170223T0600Z-170224T1800Z/
Wind River Mountains West-Wind River Mountains East-
1107 PM MST Tue Feb 21 2017

...WINTER STORM WATCH REMAINS IN EFFECT FROM WEDNESDAY EVENING
THROUGH FRIDAY MORNING...
...WINTER STORM WARNING IS CANCELLED...

The National Weather Service in Riverton has cancelled the Winter
Storm Warning. However, a Winter Storm Watch is now in effect from
Wednesday evening through Friday morning. 

* Timing...Snow is expected to redevelop late Wednesday night and
  continue through mid day Friday, heavy at times. Snow will
  continue through the day Thursday, Thursday night and through
  mid day Friday. The heaviest snowfall will likely occur between
  2 am Wednesday night through 11 am Thursday morning.

* Snowfall Accumulation...8 to 12 inches are expected, mainly on
  the southern end of the mountains.  

* Main Impact...Travel may become difficult across South Pass due
  to the snow producing slick, snow- packed roads. Periods of
  heavy snow may significantly reduce visibility. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A winter storm watch means there is a potential for significant
snow and/or blowing snow that may impact travel. Continue to
monitor the latest forecasts.

&&

$$

WYZ001-002-012-024-220715-
/O.CAN.KRIW.WS.W.0008.000000T0000Z-170222T1200Z/
Yellowstone National Park-Absaroka Mountains-
Teton and Gros Ventre Mountains-Salt River and Wyoming Ranges-
Including the cities of Lake, Mammoth, and Old Faithful
1107 PM MST Tue Feb 21 2017

...WINTER STORM WARNING IS CANCELLED...

The National Weather Service in Riverton has cancelled the Winter
Storm Warning. 

Light snow lingers across the area. Little additional accumulation
is possible tonight.

$$

WYZ020-022-222200-
/O.CON.KRIW.WS.A.0012.170223T0600Z-170224T1800Z/
Natrona County Lower Elevations-Casper Mountain-
Including the city of Casper
1107 PM MST Tue Feb 21 2017

...WINTER STORM WATCH REMAINS IN EFFECT FROM WEDNESDAY EVENING
THROUGH FRIDAY MORNING...

* TIMING...Snow will develop Wednesday night and may become 
  heavy at times after 2 am. Snow heavy at times will continue 
  through the day Thursday, Thursday night and through mid day 
  Friday. The heaviest snowfall will likely occur between 2 am 
  Wednesday night through 11 am Thursday morning.

* SNOWFALL ACCUMULATION...Ranging from up to 2 feet on Casper 
  Mountain, up to a foot and a half in the vicinity of the city 
  of Casper and 9 to 12 inches across Northern and Western 
  Natrona County. 

* MAIN IMPACT...Roads may become slick and snow covered. 
  Considerable blowing and drifting snow could make travel 
  difficult to impossible. The visibility may become 
  significantly reduced in blowing snow. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A winter storm watch means there is a potential for significant
snow and/or blowing snow that may impact travel. Continue to
monitor the latest forecasts.

&&

$$

WYZ019-222200-
/O.CON.KRIW.WS.A.0012.170223T0600Z-170224T1800Z/
Green Mountains and Rattlesnake Range-
Including the city of Jeffrey City
1107 PM MST Tue Feb 21 2017

...WINTER STORM WATCH REMAINS IN EFFECT FROM WEDNESDAY EVENING
THROUGH FRIDAY MORNING...

* TIMING...Snow will develop Wednesday night and may become 
  heavy at times after 2 am. Snow heavy at times will continue 
  through the day Thursday, Thursday night and through mid day 
  Friday. The heaviest snowfall will likely occur between 2 am 
  Wednesday night through 11 am Thursday morning.

* SNOWFALL ACCUMULATION...10 to 16 inches.

* MAIN IMPACT...Roads may become slick and snow covered. Blowing
  and drifting snow may significantly reduce visibility and could
  make travel rather difficult. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A winter storm watch means there is a potential for significant
snow and/or blowing snow that may impact travel. Continue to
monitor the latest forecasts.

&&

$$

WYZ030-222200-
/O.CON.KRIW.WS.A.0012.170223T0600Z-170224T1800Z/
East Sweetwater County-
Including the city of Wamsutter
1107 PM MST Tue Feb 21 2017

...WINTER STORM WATCH REMAINS IN EFFECT FROM WEDNESDAY EVENING
THROUGH FRIDAY MORNING...

* TIMING...Snow will develop Wednesday night and may become heavy
  at times after 2 am. Snow will continue through the day
  Thursday, Thursday night and through mid day Friday. The
  heaviest snowfall will likely occur between 2 am Wednesday night
  through 11 am Thursday morning.

* SNOWFALL ACCUMULATION...Ranging from 5 to 8 inches in Central
  Sweetwater County to up to 15 inches in Eastern Sweetwater
  County.

* MAIN IMPACT...Roads may become slick and snow covered. Blowing
  and drifting snow may significantly reduce visibility and could
  make travel rather difficult.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A winter storm watch means there is a potential for significant
snow and/or blowing snow that may impact travel. Continue to
monitor the latest forecasts.

&&

$$

WYZ017-018-222200-
/O.CON.KRIW.WS.A.0012.170223T0600Z-170224T1800Z/
Wind River Basin-Lander Foothills-
Including the cities of Riverton, Shoshoni, and Lander
1107 PM MST Tue Feb 21 2017

...WINTER STORM WATCH REMAINS IN EFFECT FROM WEDNESDAY EVENING
THROUGH FRIDAY MORNING...

* TIMING...Snow will develop Wednesday night and may become heavy
  at times after 2 am. Snow will continue through the day
  Thursday, Thursday night and through mid day Friday. The
  heaviest snowfall will likely occur between 2 am Wednesday night
  through 11 am Thursday morning.

* SNOWFALL ACCUMULATION...10 to 13 inches in Eastern Fremont
  County, 6 to 10 inches in the Riverton/Lander area, and 3 to 5
  inches around Kinnear and Pavillion.

* MAIN IMPACT...Roads may become slick and snow covered. Blowing
  and drifting snow may significantly reduce visibility and could
  make travel rather difficult.  

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A winter storm watch means there is a potential for significant
snow and/or blowing snow that may impact travel. Continue to
monitor the latest forecasts.

&&

$$

WYZ007-222200-
/O.CON.KRIW.WS.A.0012.170223T0600Z-170224T1800Z/
Owl Creek and Bridger Mountains-
1107 PM MST Tue Feb 21 2017

...WINTER STORM WATCH REMAINS IN EFFECT FROM WEDNESDAY EVENING
THROUGH FRIDAY MORNING...

* TIMING...Snow will develop Wednesday night and may become heavy
  at times after 2 am. Snow will continue through the day
  Thursday, Thursday night and through mid day Friday. The
  heaviest snowfall will likely occur between 2 am Wednesday night
  through 11 am Thursday morning.

* SNOWFALL ACCUMULATION...6 to 10 inches.

* MAIN IMPACT...Roads may become slick and snow covered. Blowing
  and drifting snow could make travel rather difficult, including
  travel through the Wind River Canyon. Blowing snow may
  significantly reduce visibility, especially at the southern end
  of the Wind River Canyon.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A winter storm watch means there is a potential for significant
snow and/or blowing snow that may impact travel. Continue to
monitor the latest forecasts.

&&

$$

WYZ011-222200-
/O.CON.KRIW.WS.A.0012.170223T0600Z-170224T1800Z/
Southeast Johnson County-
Including the city of Kaycee
1107 PM MST Tue Feb 21 2017

...WINTER STORM WATCH REMAINS IN EFFECT FROM WEDNESDAY EVENING
THROUGH FRIDAY MORNING...

* TIMING...Snow will develop Wednesday night and may become heavy
  at times after 2 am. Snow will continue through the day
  Thursday, Thursday night and through mid day Friday. The
  heaviest snowfall will likely occur between 2 am Wednesday night
  through 11 am Thursday morning.

* SNOWFALL ACCUMULATION...6 to 10 inches with the heaviest 
  snowfall expected near the Natrona County line. 

* MAIN IMPACT...Roads may become slick and snow covered. Blowing
  and drifting snow may significantly reduce visibility and could
  make travel rather difficult. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A winter storm watch means there is a potential for significant
snow and/or blowing snow that may impact travel. Continue to
monitor the latest forecasts.

&&

$$

What forecasters said that day

The local office's own words before this winter storm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Riverton, WY wrote its last area forecast discussion before this winter storm warning went out at Feb 19, 11:07 PM MST, 4 hours 8 minutes earlier.

Area forecast discussion, Feb 19, 11:07 PM MST, 4 hours 8 minutes before
Area Forecast Discussion
National Weather Service Riverton WY
1107 PM MST Sun Feb 19 2017

.Short Term...Tonight Through Wednesday (Issued at 248 PM MST)

There will be a break in the heavier snow in the west tonight
through Monday.  Strong west to southwest winds will bring
periods of high winds to the Cody foothills. A high wind warning
has been issued.  As the strong winds aloft shift further south,
high winds will be possible across Fremont and Natrona county.
Pacific moisture will increase significantly bringing a long
duration heavy snow event to the western mountains.  A strong
Pacific storm will bring heavy snow to the western mountains from
Monday afternoon through Tuesday evening. Strong west to
southwest winds will cause blowing and drifting snow. The western
valleys will see mainly rain. Snowfall of 12 to 24 inches is
expected, possibly up to 30 inches in the Teton mountains. West to
southwest winds of 25 to 30 mph with gusts of 45 to 50 mph on the
passes and upper ridges. Visibility frequently below a quarter
mile in heavy snow and blowing snow. Some rain and rain snow mix
may spill over the mountains to areas east of the continental
divide but this should be light and very spotty.

.Long Term...Wednesday Night Through Sunday

The main concern in the long range continues to be the potential
snow storm in the Wednesday night and Thursday timeframe. One change
is the models have trended a little bit slower in the onset of the
precipitation across areas East of the Divide. As a result, we
lowered POPS a bit in that area. Future shifts may want to lower
them further if this trend continues. The exception may be across
the Interstate 80 corridor which will be in the more favorable left
front quadrant of the jet.

The models have come into somewhat better agreement with the
evolution of the snowstorm, although the exact details remain in
question, as would be expected this far out from the storm. It still
appears that the biggest impact would be further east, especially in
the favored northeasterly upslope flow, especially in Natrona
County. However, the latest runs of both the GFS and European have
shifted the the best lift and QPF a bit further to the east and into
eastern Wyoming. The GFS especially so and has a place like Riverton
with only light snow. It is too early to bite too hard on these
solutions though since it is still a few days out though. For now,
we maintained the likely POPS over the favored upslope areas but
lowered them a bit elsewhere. Thursday will be a shock to the system
after the recent run of mild weather with chilly temperatures with
possible falling temperatures all day. Nothing unusual for February
however. The heaviest snow will move out after Thursday evening.

Friday looks like a cloudy and chilly day at this point. Another
wave will move through the area with another chance of snow.
However, this one is weaker and has much less moisture to work with
so mainly light snow is anticipated with it. As for next weekend, we
made few changes with many slight to chance POPS across the west
with a couple of waves moving down and mainly dry conditions
persisting East of the Divide. Temperatures will be below normal,
but not extremely cold and certainly nothing unusual for the end of
February.

&&

.Aviation.../06Z Issuance/

WEST OF THE DIVIDE...KBPI/KJAC/KPNA/KRKS ROUTES

A few snow showers in the western mountains overnight. Snow will
be developing over the western mountains Monday morning and snow
will continue through Monday night. MVFR/IFR conditions will occur
in and near the mountains. KJAC airport will see snow starting
around 15Z and snow is expected through Monday night with MVFR to
IFR conditions. KPNA and KBPI airports will see VCSH by 19Z with
snow developing at these sites between 00Z and 05Z Tuesday.
KRKS airport will have VFR conditions through the period.

EAST OF THE DIVIDE...KCOD/KCPR/KLND/KRIW/KWRL ROUTES

VFR conditions will prevail at the terminal sites through the
period. A gusty wind will occur at KCPR airport after 15Z and
this gusty wind will continue through Monday night.

&&

.Fire Weather...

There will be a break in the heavier snow in the west tonight
through Monday.  Strong west to southwest winds will bring
periods of high winds to the Cody foothills. A high wind warning
has been issued.  As the strong winds aloft shift further south,
high winds will be possible across Fremont and Natrona county.
Pacific moisture will increase significantly bringing a long
duration heavy snow event to the western mountains.  A strong
Pacific storm will bring heavy snow to the western mountains from
Monday afternoon through Tuesday evening. Strong west to
southwest winds will cause blowing and drifting snow. The western
valleys will see mainly rain. Snowfall of 12 to 24 inches is
expected, possibly up to 30 inches in the Teton mountains. West to
southwest winds of 25 to 30 mph with gusts of 45 to 50 mph on the
passes and upper ridges. Visibility frequently below a quarter
mile in heavy snow and blowing snow. Some rain and rain snow mix
may spill over the mountains to areas east of the continental
divide but this should be light and very spotty.   The areas with
precipitation in the west will have poor smoke dispersal through
Wednesday, while the winder areas east of the mountains will see
fair to good smoke dispersal in the afternoons. The Bighorn basin
and Wind River basin will have less wind and poor smoke dispersal.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...

Winter Storm Watch from Monday afternoon through Tuesday evening
for WYZ001-002-012-014-024.

High Wind Watch from late tonight through Tuesday morning for
WYZ015-018>020.

High Wind Warning from 6 PM this evening to 5 PM MST Monday for
WYZ003.

&&

SHORT TERM...C.Baker
LONG TERM...CH
AVIATION...AR
FIRE WEATHER...C.Baker
Hazardous weather outlook, Feb 20, 2:43 AM MST, 32 minutes before
Hazardous Weather Outlook
National Weather Service Riverton WY
243 AM MST Mon Feb 20 2017

WYZ001>020-022>030-211315-
Yellowstone National Park-Absaroka Mountains-Cody Foothills-
North Big Horn Basin-Southwest Big Horn Basin-
Southeast Big Horn Basin-Owl Creek and Bridger Mountains-
Bighorn Mountains West-Bighorn Mountains Southeast-
Northeast Johnson County-Southeast Johnson County-
Teton and Gros Ventre Mountains-Jackson Hole-
Wind River Mountains West-Wind River Mountains East-
Upper Wind River Basin-Wind River Basin-Lander Foothills-
Green Mountains and Rattlesnake Range-
Natrona County Lower Elevations-Casper Mountain-Star Valley-
Salt River and Wyoming Ranges-Upper Green River Basin Foothills-
Upper Green River Basin-South Lincoln County-
Rock Springs and Green River-Flaming Gorge-East Sweetwater County-
243 AM MST Mon Feb 20 2017

...Flood Advisory remains in effect for the Big Horn River
roughly between Manderson and Greybull Today...

...Winter Storm Warning for the Western Mountains this Afternoon
through Tuesday Night...

...Multiple High Wind Warnings and Watches for areas east of the
Divide through Tuesday Evening...

This Hazardous Weather Outlook is for Western and Central Wyoming.

.DAY ONE...Today and Tonight

Ice jam flooding continues to slowly decrease across portions of
northern Wyoming.

Significant snow and blowing snow developing over the western
mountains today, continuing through Tuesday night. Please see the
winter storm warning for more details. Snow developing in the
western valleys today, but mixing with or changing to rain below
7000 feet in the afternoon and tonight.

Strong to high wind developing late this afternoon across portions
of central Wyoming east of the Continental Divide. Please see the
high wind product for more details.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday

Tuesday through Tuesday night...Periods of moderate to heavy snow
will continue across the western mountains. Rain will mix with
snow in the valleys, changing back over to snow by Tuesday
evening.

Strong to high wind continues over portions of the area, east of
the Continental Divide Tuesday and Tuesday evening.

Late Wednesday Night Through Thursday Night...Significant snow
possible in central Wyoming along with windy conditions causing
significant blowing and drifting snow.

.SPOTTER INFORMATION STATEMENT...

Spotters are encouraged to report any river or creek flooding, as
well as snowfall amounts. Thank you!

Team Riverton

The office that day

Everything else NWS Riverton, WY issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Feb 20, 8:11 AM MSTAreal Flood WarningRIWBig Horn48 hr
Feb 20, 8:21 AM MSTAreal Flood WarningRIWBig Horn48 hr

Nearby

Winter Storm Warnings in Wyoming, 2017Every winter storm warning in 2017

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.