Alert archive / Wyoming / Winter Storm Warnings in 2018

Winter Storm Warning 14, NWS Riverton, WY

December 11, 20184 counties in Wyoming

NWS Riverton, WY issued this winter storm warning at Dec 11, 2018, 11:21 AM MST for 4 counties in Wyoming. It took effect at Dec 11, 2018, 11:00 PM MST. It was in force for 16 hr. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Dec 11, 2018, 11:21 AM MST (18:21 UTC)
In effect from
Dec 11, 2018, 11:00 PM MST
Expired
Dec 12, 2018, 3:16 PM MST
In force
16 hr
Issued by
NWS Riverton, WY

Counties Fremont County, WY, Lincoln County, WY, Sublette County, WY, Teton County, WY

The radar

The Riverton/Lander radar (KRIW), 120 km from the middle of the area, began a volume at 18:24 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.

The nearest sounding before it

Elko, NV (KLKN), launched 12:00Z, 6.4 hours before the alert went out and 424 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, Elko, NV at 12:00Z on 2018-12-11Temperature 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, Elko, NV at 12:00Z on 2018-12-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -2 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
677 m above ground
0-6 km bulk shear
34 kt
0-1 km storm-relative helicity
-2 m²/s²
0-3 km storm-relative helicity
35 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

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 Dec 11, 9:53 AM MST, 1 hour 28 minutes earlier.

Area forecast discussion, Dec 11, 9:53 AM MST, 1 hour 28 minutes before
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Hazardous weather outlook, Dec 11, 2:52 AM MST, 8 hours 29 minutes before
Hazardous Weather Outlook
National Weather Service Riverton WY
252 AM MST Tue Dec 11 2018

WYZ001>020-022>030-121000-
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-
252 AM MST Tue Dec 11 2018

...High Wind Warning for Cody Foothills from 2 PM Today until 5 AM
Wednesday...
...High Wind Warning for Southeast Fremont and Natrona Counties
from 11 PM Tuesday night until 2 PM Wednesday...
...Winter Storm Watch Teton and Gros Ventre Ranges late Tuesday
Night and Wednesday...
...High Wind Watch for the WInd River Basin and Northeast Johnson
County Late Wednesday Evening through Thursday Morning...

This Hazardous Weather Outlook is for Western and Central
Wyoming.

.DAY ONE...Today and Tonight.

Strong winds developing across the Cody Foothills late this
afternoon through this evening. Strong southwest winds developing
from southeast Fremont County through the Casper area late
tonight. Please see High Wind Warnings for details.

Snow increasing across the western mountains and Far West valleys
tonight.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday.

Wednesday...Significant snow expected in the far west mountains
and valleys along with gusty to strong wind. A period of very
strong wind and snow along the Interstate 80 corridor. A chance of
snow showers with brief heavy snow showers possible across
central Wyoming.

Wednesday night and Thursday morning...Strong northwest wind
possible across the Wind River Basin and northeast Johnson County
including Interstates 25 and 90.

.SPOTTER INFORMATION STATEMENT...

Please report wind gusts over 50 mph and any snow amounts.

The office that day

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

IssuedProductOfficeCountiesLasted
Dec 11, 2:52 AM MSTHigh Wind WatchRIWFremont, Johnson24 hr
Dec 11, 2:52 AM MSTHigh Wind WarningRIWFremont, Hot Springs, Johnson, Natrona, Park, Sweetwater42 hr
Dec 11, 11:21 AM MSTWinter Weather AdvisoryRIWLincoln, Park, Sublette, Teton28 hr

Nearby

Winter Storm Warnings in Wyoming, 2018Every winter storm warning in 2018

Sources

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