High Wind Warning 4, NWS Riverton, WY

094 
WWUS75 KRIW 010240
NPWRIW

URGENT - WEATHER MESSAGE
National Weather Service Riverton WY
740 PM MST Thu Feb 29 2024

WYZ019-020-011800-
/O.CON.KRIW.HW.W.0004.240301T0600Z-240302T0000Z/
Green Mountains and Rattlesnake Range-
Natrona County Lower Elevations-
Including the cities of Jeffrey City and Casper
740 PM MST Thu Feb 29 2024

...HIGH WIND WARNING REMAINS IN EFFECT FROM 11 PM THIS EVENING TO
5 PM MST FRIDAY...

* WHAT...Southwest winds 25 to 40 mph with gusts up to 65 mph
  expected.

* WHERE...Green Mountains and Rattlesnake Range and Natrona 
  County Lower Elevations.

* WHEN...From 11 PM this evening to 5 PM MST Friday.

* IMPACTS...Travel could be difficult, especially for high 
  profile vehicles.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

People should be careful in forested areas and around trees. Use
extra caution when driving, especially if operating a high
profile vehicle. Secure outdoor objects.

&&

$$

WYZ018-011500-
/O.CON.KRIW.HW.A.0004.240301T0300Z-240301T1500Z/
Lander Foothills-
Including the city of Lander
740 PM MST Thu Feb 29 2024

...HIGH WIND WATCH REMAINS IN EFFECT THROUGH FRIDAY MORNING...

* WHAT...Southwest winds 25 to 40 mph with gusts up to 65 mph 
  possible.

* WHERE...Lander Foothills.

* WHEN...From 8 PM MST this evening through Friday morning.

* IMPACTS...Travel could be difficult, especially for high 
  profile vehicles. There is potential for strong mountain waves 
  that would bring very strong wind to the Lander Foothills and 
  the town of Lander. If this occurs, damage to trees and power 
  lines is possible.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Monitor the latest forecasts and warnings for updates on this
situation. Fasten loose objects or shelter objects in a safe
location prior to the onset of winds.

&&

$$

For more information from the National Weather Service visit
https://weather.gov/riw

600 
WWUS75 KRIW 010920
NPWRIW

URGENT - WEATHER MESSAGE
National Weather Service Riverton WY
220 AM MST Fri Mar 1 2024

WYZ018-011030-
/O.CAN.KRIW.HW.A.0004.000000T0000Z-240301T1500Z/
Lander Foothills-
Including the city of Lander
220 AM MST Fri Mar 1 2024

...HIGH WIND WATCH IS CANCELLED...

High wind is not longer expected. Wind gusts to 50 mph will remain
possible through the night, especially in the higher elevations to
the west of Lander.

$$

WYZ019-020-020000-
/O.EXT.KRIW.HW.W.0004.000000T0000Z-240303T0000Z/
Green Mountains and Rattlesnake Range-
Natrona County Lower Elevations-
Including the cities of Jeffrey City and Casper
220 AM MST Fri Mar 1 2024

...HIGH WIND WARNING NOW IN EFFECT UNTIL 5 PM MST SATURDAY...

* WHAT...Southwest winds 30 to 40 mph with gusts up to 65 mph.

* WHERE...Green Mountains and Rattlesnake Range and Natrona 
  County Lower Elevations.

* WHEN...Until 5 PM MST Saturday. Many areas will see a decrease
  in the wind Friday night before increasing again on Saturday.

* IMPACTS...Travel could be difficult, especially for high profile
  vehicles.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

People should be careful in forested areas and around trees. Use
extra caution when driving, especially if operating a high
profile vehicle. Secure outdoor objects.

&&

$$

For more information from the National Weather Service visit
https://weather.gov/riw

395 
WWUS75 KRIW 011923
NPWRIW

URGENT - WEATHER MESSAGE
National Weather Service Riverton WY
1223 PM MST Fri Mar 1 2024

WYZ019-020-021400-
/O.CON.KRIW.HW.W.0004.000000T0000Z-240303T0000Z/
Green Mountains and Rattlesnake Range-
Natrona County Lower Elevations-
Including the cities of Jeffrey City and Casper
1223 PM MST Fri Mar 1 2024

...HIGH WIND WARNING REMAINS IN EFFECT UNTIL 5 PM MST SATURDAY...

* WHAT...Southwest winds 40 to 50 mph with gusts up to 60 to 70 
  mph.

* WHERE...Green Mountains and Rattlesnake Range and Natrona 
  County Lower Elevations.

* WHEN...Until 5 PM MST Saturday. Many areas will see a decrease
  in the wind Friday night before increasing again on Saturday
  with the peak being late Saturday morning and into the mid
  afternoon hours.

* IMPACTS...Travel could be difficult, especially for high profile
  vehicles.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

People should be careful in forested areas and around trees. Use
extra caution when driving, especially if operating a high
profile vehicle. Secure outdoor objects.

&&

$$

For more information from the National Weather Service visit
https://weather.gov/riw

358 
WWUS75 KRIW 020942
NPWRIW

URGENT - WEATHER MESSAGE
National Weather Service Riverton WY
242 AM MST Sat Mar 2 2024

WYZ019-020-030000-
/O.CON.KRIW.HW.W.0004.000000T0000Z-240303T0000Z/
Green Mountains and Rattlesnake Range-
Natrona County Lower Elevations-
Including the cities of Jeffrey City and Casper
242 AM MST Sat Mar 2 2024

...HIGH WIND WARNING REMAINS IN EFFECT UNTIL 5 PM MST THIS
AFTERNOON...

* WHAT...Southwest winds 40 to 50 mph with gusts up to 60 to 70 
  mph.

* WHERE...Green Mountains and Rattlesnake Range and Natrona 
  County Lower Elevations.

* WHEN...Until 5 PM MST this afternoon. The strongest wind is
  expected from late morning to mid afternoon.

* IMPACTS...Travel could be difficult, especially for high 
  profile vehicles.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

People should be careful in forested areas and around trees. Use
extra caution when driving, especially if operating a high
profile vehicle. Secure outdoor objects.

&&

$$

For more information from the National Weather Service visit
https://weather.gov/riw

761 
WWUS75 KRIW 022356
NPWRIW

URGENT - WEATHER MESSAGE
National Weather Service Riverton WY
456 PM MST Sat Mar 2 2024

WYZ019-020-030100-
/O.EXP.KRIW.HW.W.0004.000000T0000Z-240303T0000Z/
Green Mountains and Rattlesnake Range-
Natrona County Lower Elevations-
Including the cities of Jeffrey City and Casper
456 PM MST Sat Mar 2 2024

...HIGH WIND WARNING WILL EXPIRE AT 5 PM MST THIS AFTERNOON...

Wind gusts of 50 to 55 mph will remain possible for the next hour
or two before a strong cold front moves through the area. An
isolated gust up to 60 mph could occur with snow showers along and
behind the front. Thus, the main threat for high winds has
subsided and the warning will be allowed to expire. 

$$

For more information from the National Weather Service visit
https://weather.gov/riw

Area Forecast Discussion
National Weather Service Riverton WY
1022 AM MST Thu Feb 29 2024

.KEY MESSAGES...

- Significant winter storm approaching western Wyoming tonight,
  with heavy snow and strong winds continuing through Saturday.

- Strong winds expected across central Wyoming Friday and
  Saturday.

&&

.DISCUSSION...
Issued at 221 AM MST Thu Feb 29 2024

Once more day of strong ridging bringing temps well above
average, with widespread 40s and 50s across the region. Should
do some considerable melting to the outdoor hockey rink here in
Riverton... Southwesterly gradient flow between systems tonight
will bring high winds to a section of central Wyoming overnight
tonight into Friday. Have done some adjustments to the High Wind
Watches for tonight, mainly focused on the most prone areas in
central Wyoming.

The well-advertised winter storm then arrives for western
Wyoming tonight. Pacific moisture tap still forecast to remain
strong ahead of the next trough, so snow production will be
considerable across all zones of western Wyoming. Add in an
associated jet max drawing around the bottom of the Pacific
trough, which will mix down into the higher elevations tonight
and Friday. This will result in significant blowing snow both at
higher elevations and in western valleys. Have upgraded Jackson
Hole, Star Valley, and the upper Green River Foothills to a
Winter Storm Warning for snow accumulation and blowing snow.
With the trough gradually making landfall by Saturday, the deep
southwest flow continues ahead of it, continuing to directly
impact the western mountains. Overall accumulations in the
mountains over 18 inches remains near definite (>90%), with
isolated areas peaking near 3 feet.

Placement of the jet streak will keep the Central Wyoming wind
corridor in a favorable location for strong winds again on
Saturday, which may need another High Wind Warning for the
daylight hours again.

Once the trough finally lifts out of the Rockies early next
week, semi-zonal flow tries to set up. While there are some
differences in model solutions, there is consistent flow off the
Pacific, which would keep light snow going out west well into
the middle of next week.

&&

.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 1012 AM MST Thu Feb 29 2024

West of the Divide... KBPI/KJAC/KPNA/KRKS Terminals

VFR conditions to start the period with some nearing light snow
west of JAC, carrying VCSH as such. Otherwise, relatively light
southerly winds less than 10kts will increasing to 25kt gusts by
22Z at JAC through the overnight due to downsloping. Winds will
not increase at RKS until later Friday morning towards the end
of the period. Higher confidence in snow on station at PNA, BPI,
and JAC by 12-13Z Friday morning with the stronger first wave.
MVFR ceilings and visibility at that point in alignment with
LAMP and BUFKIT sounding data. This will last through the end of
the period and into the next TAF cycle throughout much of
Friday.

East of the Divide...KCOD/KCPR/KLND/KRIW/KWRL Terminals

VFR conditions expected for all TAF sites throughout the period
with some scattered mid and upper level clouds. Gusty winds at
COD and CPR with funneling out of the southwest up to 25-35kt
respectively. RIW and WRL will remain relatively light around
10-12kts. LND will be the same as well, however, models are
hinting at a downsloping nocturnal wind event after 05Z gusting
up to 45kts down snow showers over the Winds near to the south
and southwest until around 12Z before sunrise Friday morning.
Medium confidence with short term FVS data supporting occurrence
as well as some others but not as high in velocity.

Please see the Aviation Weather Center and/or CWSU ZDV and ZLC for
the latest information on icing and turbulence forecasts.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...
Winter Storm Warning from 5 PM this afternoon to 11 PM MST
Saturday for WYZ001-002-012>015-023>025.

Winter Storm Watch from this evening through Saturday evening
for WYZ016.

High Wind Watch from 8 PM MST this evening through Friday
morning for WYZ018.

High Wind Watch from late tonight through Friday afternoon for
WYZ019-020.

Winter Storm Watch from Friday afternoon through Saturday
evening for WYZ027.

&&

DISCUSSION...Straub
AVIATION...Lowe

Hazardous Weather Outlook
National Weather Service Riverton WY
229 AM MST Thu Feb 29 2024

WYZ001>020-022>030-011330-
Yellowstone National Park-Absaroka Mountains-Cody Foothills-
North Bighorn Basin-Southwest Bighorn Basin-Southeast Bighorn 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-
229 AM MST Thu Feb 29 2024

...Winter Storm Warnings in effect for a large portion of western
Wyoming tonight through Saturday...

This Hazardous Weather Outlook is for Western and Central Wyoming.

.DAY ONE...Today and tonight.

Strong winds continue across central Wyoming this afternoon.

Moderate to heavy snow begins in northwestern Wyoming overnight
tonight. Winds will also increase in these areas overnight, causing
widespread blowing snow.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday.

Snow expands across western Wyoming through the day Friday. Wind
remains strong across central Wyoming, with some gusts near 60 mph.

Friday night through Saturday afternoon...Moderate to heavy snow
persists across western Wyoming, with light snow spreading south, and
east of the Continental Divide. Wind remains elevated, with High
Wind possible again Saturday afternoon. Widespread blowing snow will
occur across western Wyoming.

.SPOTTER INFORMATION STATEMENT...

Weather spotters are encouraged to report significant weather
conditions according to Standard Operating Procedures.