textproduct: Cheyenne

KEY MESSAGES

- Cool and unsettled weather will remain in place through tonight with several chances for rain showers.

- Accumulating snow is expected for the higher mountains above 9000 ft in elevation tonight through Wednesday evening.

- After a brief warmup Thursday, another strong cold front will sweep through the area and bring additional chances for rain, snow, and high winds Thursday afternoon into Friday.

SHORT TERM /THROUGH FRIDAY NIGHT/

Issued at 223 PM MDT Wed Apr 1 2026

An active weather work week is finally upon us! Multiple shortwaves will be pushing through the forecast area. Continuing this evening, a negatively tilted shortwave will continue to push in from the West. Model soundings show our dry layer near the surface to slowly erode away allowing for greater precipitation chances to occur overnight. Southwesterly flow at 700mb is expected to continue through the late mornings hours before more westerly flow develops as a 700mb low attempts to develop with the approaching system. A closed system at 700mb is progged to develop by 00Z Thursday in most models, further showcasing the increasing strength of this system. A stout Colorado Low will develop off the Rocky Mountains in eastern Colorado this afternoon and evening, leading to northwesterly flow across areas east of the Laramie Range and colder air funneling down into the region. Mountain precipitation has already begun across the Sierra Madre and Snowy Ranges, but precipitation chances spread northeastward through the late morning and early afternoon hours. Precipitation is anticipated to start as rain across much of the area as 700mb temperatures remain too warm for snow. Some hi-res model soundings suggest some CAPE pockets for the showers to take advantage of. So with this small amount of CAPE available it can't be ruled out for some weak thunderstorms or claps of thunder as these showers pass overhead. NAEFS Mean Precipitable Water is above the 99th percentile this afternoon, so good moisture is anticipated with this system. A brief lull in precipitation is expected early Thursday morning through the afternoon hours before precipitation chances start increasing west to east. Upper-level flow will remain largely zonal throughout the morning hours Thursday before the next upper-level trough starts to move into the Intermountain West and upper-level flow turns southwesterly once more. The closed, 500mb system starts to move into western Wyoming by Thursday evening, with much of the western portions of the CWA under strong, southwesterly flow and within the left exit region of the trough, favoring synoptic lift across the region. Another 700mb system is progged to develop late Thursday night into the early morning hours Friday, leading to increasing height gradients and strong, southwesterly flow across western portions of the CWA and strong, westerly flow across the Laramie Range. There is a little uncertainty with the precipitation chances during this time as it will be a battle between downsloping winds and the enhanced forcing this 700mb system brings. The 700mb jet also ramps up Thursday night into Friday that could possibly have a couple of brief blips of high winds along the I-80 and I-25 corridor of Southeast Wyoming. Because the 700mb jet continues to haphazardly ramp up to possible high wind criteria then die down much like a rough running engine, the high wind watches were left as is. Our in house algorithm also supports the general train of thought for the low confidence high wind forecast as it bounces between 40 to 60 percent probabilities between elevated and high winds.

LONG TERM /SATURDAY THROUGH TUESDAY/

Issued at 223 PM MDT Wed Apr 1 2026

The weekend into early next week will feature a return to drier weather as northwest flow transitions to weak ridging across the western CONUS. Temperatures will run near to slightly above normal throughout the period, however we will not see a return to record high temperatures, at least for the next week or so. Northwest flow behind our departing system on Saturday will result in a seasonably chilly, but sunny day across southeast Wyoming and western Nebraska. As ridging builds in from the southwest and mid-level temperatures warm, expect a moderating trend to temperatures for Sunday with high confidence in dry weather expected once again.

A bit more uncertainty enters the forecast from Monday through Wednesday as a plume of subtropical moisture moves in through the southwestern CONUS. This feature, underneath the building ridge, gives almost a summery-flavor to the weather pattern with increasing chances of afternoon convective showers and possibly thunder over the higher terrain. At the very least, an increase in mid-level moisture will make for cloudier afternoons from Monday through midweek. Despite the cloud cover, warming mid-level temperatures will compensate resulting in highs still running above average through the period. Late in the long-term period on Wednesday into Thursday, attention shifts to the chance of a more robust storm system to move through the Central Rockies. A large amount of spread exists in ensemble guidance for this period, with some members taking a stronger low-pressure system through the region with rain and mountain snow, and others limiting this event to a brief period of moisture and a cold front. Still, the next major opportunity for some form of accumulating precipitation of note looks to arrive on Wednesday evening through Thursday of next week.

AVIATION /06Z TAFS THROUGH 06Z FRIDAY/

Issued at 1052 PM MDT Wed Apr 1 2026

A progressive upper level trough will push east of the region tonight, with rainfall and high elevation snow briefly ending after midnight. Can't rule out some terminals in/out of fog for the rest of the night through 15z Thursday depending on cloud cover. Strong gusty winds expected for KRWL and KLAR after 12z as a strong cold front moves into the region.

HAZARDS/WEATHER TRENDS: Conditions will temporarily improve at the southeast Wyoming terminals over the next few hours with VFR conditions expected by 08z to 11z. Main concern for the rest of tonight and into early Thursday will be the potential for fog and LIFR CIGS. Tweaked the timing at most locations since the extent of precipitation is not quite as widespread as previously thought. Added VCFG for terminals which have a 10% to 25% chance of locally dense fog. KAIA has the highest probability, so left the prevailing LIFR conditions going between 09z and 15z. Fog and low CIGS will lift by 17z for all terminals.

CYS WATCHES/WARNINGS/ADVISORIES

WY...High Wind Watch from Thursday evening through Friday afternoon for WYZ106. High Wind Watch from Thursday morning through Thursday afternoon for WYZ109. High Wind Watch from Thursday morning through Friday afternoon for WYZ110. Winter Weather Advisory until 9 PM MDT this evening for WYZ112- 114. High Wind Watch from Thursday morning through Friday evening for WYZ116-117. High Wind Watch from Thursday evening through Friday afternoon for WYZ118. NE...None.