textproduct: Cheyenne

KEY MESSAGES

- Strong westerly winds and critical fire danger will continue through early Saturday evening.

- A strong cold front Saturday evening will bring much colder temperatures and a quick round of locally heavy snow showers, with potential for widespread light accumulations.

- Strong northwest to north winds will continue over the High Plains into Sunday, producing sub-zero wind chill temperatures.

- Record breaking warm temperatures are expected to return to the forecast for the second half of the week ahead.

SHORT TERM /THROUGH SUNDAY NIGHT/

Issued at 300 PM MDT Sat Mar 14 2026

Widespread strong winds continue across the area today, but big changes are just around the corner. Unfortunately, these changes will not mean less wind, just a flip to a much colder northerly wind instead of the warm westerly wind. Today's wind is mostly proceeding as expected, although the westerlies were a little slower than expected to push the shallow, cool airmass out of the High Plains this morning. Widespread gusts of 50 to 70 mph are being observed over southeast Wyoming this afternoon. Wind gusts up to around 80 mph are showing up in the typical areas as well. Cloud cover has been on the increase as a powerful Pacific trough approaches the area. This system will be carrying a very strong cold front along with it. Current observations put the front around a Buffalo to Gillette to Rapid City line now. This will race southward over the afternoon and evening, reaching Douglas and Glenrock around 7-8PM, and then the I-80 corridor between 10PM and midnight. This front will have several impacts, including more wind, snow, and cold temperatures. We'll break down each below.

WIND: A narrow, more powerful 700-mb jet will push southward just ahead of the frontal boundary, so we may see winds peak later this afternoon or early evening, just before the wind direction changes. A few gusts in the 80 to 90 mph range cannot be ruled out during this period in the wind prone areas. Temperatures will plummet quickly behind the front, by perhaps 15-20F in a half hour or so. Winds will also suddenly shift to the north or northwest. The frontal boundary itself could push some gusts in the 60 to 70 mph range, but this should drop back to around a more consistent 45 to 60 mph later tonight over the High Plains. A few hours after the frontal passage, the threat for high winds will decrease in Carbon and Albany counties. These High Wind Warnings should be able to expire on time. Along and east of the Laramie Range, a very strong pressure gradient will keep elevated to high winds in place through Sunday morning. Confidence isn't all that high in reaching 60+mph consistently, but the probability of at least a few gusts exceeding this criteria is high enough to warrant upgrading all remaining High Wind Watches. The pressure gradient will begin to weaken late Sunday morning through the afternoon, and we should be able to enjoy perhaps 12-18 hours without any high wind headlines in affect for the area.

SNOW: A narrow plume of elevated moisture will push through the area with tonight's cold front. Extracting this moisture will be somewhat difficult, as models show clear, strong negative theta-e advection behind the front. However, strong frontogenesis and mechanical forcing caused by rapid surface pressure rises, with a little boost from favorable jet streak dynamics and QG ascent. This will allow for a short window for fairly good forcing. Instability and steep lapse rates will also be present along the front, so some snow showers could take on convective characteristics. Precipitation rates will be heavy at times, and when combined with the plummeting temperatures and strong winds, we could see some areas reaching the criteria for snow squalls. While scattered snow showers will continue through the night and into Sunday morning, the snow squall potential should be concluded by around midnight as the best frontogenesis and mechanical forcing pushes south and east. Overall accumulations are fairly modest due to the brief nature of this event. However, impacts could be higher than your typical light snow event due to the snowfall rates, wind speeds, and temperature drop. Therefore, the Winter Weather Advisory was expanded to include Converse and Niobrara counties, and the I-80 corridor near Arlington/Elk Mountain. These areas have the highest confidence in seeing more than 1" of snow, which will probably cause travel impacts as it blows around. We will also need to watch the Laramie Valley, I-80 summit, and the remaining Pine Ridge/US-20 corridor towards Chadron for possible expansions of the Advisory. Elsewhere, look for between 0.5 and 1.5" of snow (that will be very difficult to measure with the wind).

Snow showers may pick up in coverage and intensity again Sunday afternoon. Behind this shortwave trough, models show a stratospheric intrusion pushing the tropopause down to around 500 to even 600-mb. In fact, 500-mb temperatures are pushing climatological minimums per the NAEFS mean, indicating unusually cold temperatures aloft. That will lead to steep lapse rates, and shallow convective snow showers should develop with weak daytime surface heating. This activity could be locally intense once again. The main areas to watch will be the typical northwest flow low level lee convergence zones, including northern Laramie county/southern Platte county (converging in the lee of the northern Laramie range), and Dawes county (converging in the lee of the Black Hills). Models often under-do this type of post-storm system convective snow shower activity, so later shifts may need to nudge PoPs up as confidence improves later.

COLD: Lastly, we have the cold temperatures. This will be an unusually cold airmass for mid-March, especially so considering it will be bookended by near record warmth both before and after. 700- mb temperatures bottom out around -16 to -20C across the area, which will actually be close to the climatological first percentile. A very cold airmass combined with strong winds will push wind chills well below zero for much of the area by Sunday morning. Actual high temperatures will be stuck in the 20s for most of the area during the afternoon. While cloud cover will start increasing from the west again Sunday night, we should have several hours of clear skies that will allow for temperatures to take another dive as winds lighten up, especially for Laramie and eastward. Monday may start off in the single digits for much of the area.

Warm air advection will return to the area Monday as the synoptic weather pattern concluded zonal flow and returns to the western ridge/eastern trough configuration. The exceptionally strong western ridge will begin to encroach eastward on Monday, pushing highs back to near seasonal averages for Monday. As with most warm air advection setups, we will need to watch for gap winds increasing again too. The Arlington area has a 50 to 60% of high winds beginning around daybreak Monday, but the probability for high winds is lower across the rest of the area.

LONG TERM /MONDAY THROUGH FRIDAY/

Issued at 300 PM MDT Sat Mar 14 2026

On Tuesday, An upper level ridge will be pushing into the Western Coast centered near the California\Nevada border. The Intermountain West will be in Northwest flow with the strongest part of the jetstream centered over Southeast Montana and the Dakotas. With a weak shortwave diving into the Northern Red River Valley our height gradient becomes compressed intensifying the 700mb jet to generally around 55-60 knots with the GFS having a couple brief instances of accelerations greater than 60. The Craig to Casper height gradient difference increases from 50meters to 85meters by the afternoon increasing our confidence in potential high winds for Tuesday. Our in-house high wind algorithm places high confidence in the wind prones hitting high wind criteria from 40 percent to 80/90 percent by noon on Tuesday. As this ridge slowly approaches the Four Corners region, the jetstream should be slowly pushing north as well tapering off our winds throughout the day Wednesday. Looking at cluster analysis there is some uncertainty in the timing of the arrival of the ridge as some members of the grand ensemble have it arriving later and less amplified than others. A later and less amplified ridge equates to the extension of the high winds through the end of the week as the jetstream won't be pushed North without the amplified Ridge. In warmer news, this ridge also has the makings of a fun death ridge by the middle to end of the week. Meaning 700mb temperatures rise between 10 to 14C and surface temperatures rise into the 90 to 99th percentile later this week depicted by NAEFS. To give everyone an idea of the potential magnitude of this ridge. The high winds look to potentially stop by Wednesday afternoon/evening and the high temperatures start in the 30/40's at the beginning of the week and end in the 70's to 80's upon the arrival of this ridge with no precipitation chances as well after Tuesday. So this ridge will be something to keep an eye on as Fire weather concerns look to amplify as well with this ridge.

AVIATION /00Z TAFS THROUGH 00Z MONDAY/

Issued at 545 PM MDT Sat Mar 14 2026

Strong cold front will push south across the region this evening with strong westerly winds becoming more northerly over the next 6 hours. Periods of light to moderate snow expected with IFR conditions through early Sunday morning.

HAZARDS/WEATHER TRENDS:

Over the next few hours, will be dealing with strong winds ahead of the cold front (00z and 05z). Already seeing gusts as high as 65 knots, and expected this to continue over the next few hours until the front moves into southeast Wyoming by 03z. Winds will then briefly decrease, shift into the north, and become gusty after 06z through most of the day on Sunday.

Otherwise, snow will develop from north to south between 03z and 07z. The most favorable areas to see prolonged IFR conditions in snow will be KCDR, KAIA, and KLAR and KRWL for southeast Wyoming. All other terminals may see brief IFR conditions in moderate snow and/or snow squall-like conditions, but duration and areal coverage is pretty uncertain at this time...so will go with MVFR prevailing for now.

CYS WATCHES/WARNINGS/ADVISORIES

WY...Red Flag Warning until 8 PM MDT this evening for WYZ418- 430>433. High Wind Warning until noon MDT Sunday for WYZ101-102-106>108- 116>119. Winter Weather Advisory from 7 PM this evening to 9 AM MDT Sunday for WYZ101>103. High Wind Warning until midnight MDT tonight for WYZ103>105- 109-113. High Wind Warning until 3 AM MDT Sunday for WYZ110-115. Winter Weather Advisory from 9 PM this evening to 9 AM MDT Sunday for WYZ110. Winter Weather Advisory until noon MDT Sunday for WYZ114. NE...Red Flag Warning until 8 PM MDT this evening for NEZ435>437. High Wind Warning from 8 PM this evening to 3 PM MDT Sunday for NEZ002-003-021-055. High Wind Warning until 3 PM MDT Sunday for NEZ019-020-054-095- 096.