textproduct: Cheyenne

KEY MESSAGES

- Quieter weather through the evening hours before precipitation chances return starting over the mountains.

- Widespread snowfall possible Monday into Tuesday and early Wednesday morning.

- Next impactful system expected to arrive late Wednesday night through the end of the work week.

SHORT TERM /THROUGH TUESDAY NIGHT/

Issued at 142 AM MST Sun Mar 1 2026

One day of quiet weather is expected today before precipitation chances ramp back up as the next winter system moves through the region to start the week. For Sunday, upper-level ridging remains in place throughout most of the day, but the ridge begins to weaken as an upper-level trough moves into the western CONUS starting late Sunday night into early Monday morning. As a result, upper-level winds will shift from northwesterly during the morning and afternoon hours to westerly starting in the overnight hours and continuing through the early morning hours Monday. A subtle 500mb shortwave is traversing across southern portions of the CWA at this time, leading to the increasing cloud cover overhead and mountain snowfall chances as 500mb cyclonic vorticity advection pushes over the mountains. Additionally, a weak 700mb shortwave is passing through the region now through about mid-morning, further supporting increasing synoptic forcing and precipitation chances. Elevated 700mb winds this morning could lead to some breezy conditions across the Panhandle with gusts up to 40mph possible throughout the overnight hours, but likely dying off come sunrise. The next band of 500mb vorticity move southwest to Northwest across the CWA starting this evening as well as another diffuse 700mb shortwave. This will keep mountain snowfall ongoing and likely increasing precipitation chances in the lower elevations, though mostly along and west of the Laramie Range. Significant snowfall accumulation is not anticipated with this event, but the mountains could pick up a quick 2 to 6 inches of snowfall throughout the day, while the lower elevations may see a few hundredths of precipitation, likely rainfall due to warm 700mb temperatures and surface temperatures in the 50s and 60s today. The best event looks to start impacting the region to start the week, as that upper-level trough moves closer to the CWA.

For Monday, the upper-level ridge will weaken significantly and be pushed off to the east by the approaching upper-level trough. This upper-level trough will be the next significant weather producer for the region, likely resulting in accumulating snowfall for many locations. The region will be under the influence of the left exit region of the upper-level jet starting early Monday morning and continuing through most of the day as the trough pushes further east. This is a favorable location for synoptically-driven ascent across the region. Additionally, the southwesterly flow aloft and through much of the atmosphere will help advect in additional Pacific Moisture, with the NAEFS Mean Integrated Water Vapor Transport suggesting IVT values above the 90th percentile for much of the are. Precipitable Water values are also progged to be in the 99th percentile and higher throughout the day Monday. As a result, ample moisture will be in place to get precipitation, especially with the help of synoptic lift. Additionally, further down at 700mb a low will start to develop over southeastern Idaho, northeastern Utah, and wester Wyoming, leading to enhanced southwesterly flow across the region. This continues to advect Pacific Moisture into the region, especially across the Sierra Madre and Snowy Ranges. With upslope flow ongoing at the surface and 700mb, as well as 700mb warm air advection, the mountains, especially the Sierra Madres, are expected to receive significant precipitation Monday. Precipitation should be primarily snow across the mountains for Monday, but likely rain in the lower elevations with temperatures in the 50s and 60s once more. A cold front pushes through Monday night into Tuesday morning, dropping 700mb temperatures to the -5 to -3C range, a favorable range for snowfall everywhere.

The upper-level trough will push through the region Tuesday, finally exiting to the east into the overnight hours Tuesday. Ample synoptic forcing will be present as the trough moves through, along with the ample 500mb vorticity associated with it. 700mb temperatures will remain around the -6 to -4C range all day Tuesday, leading to all precipitation likely to be snow across the region. Light accumulations are possible outside of the mountains, while heavier accumulations are likely in the mountains. The mountains look to receive another 6 to 12 inches of snow late Monday night through early Tuesday morning, with lower elevations remaining in the trace to 2 inches range, through Wednesday morning. Snow begins to taper off early Wednesday morning into the mid-morning hours as the upper- level trough pushes off to the east of the CWA and northerly upper- level flow returns once again.

LONG TERM /WEDNESDAY THROUGH SATURDAY/

Issued at 142 AM MST Sun Mar 1 2026

Looking mid-week and beyond, Wednesday will likely be the only dry and quiet day of the week. Snow comes to an end early Wednesday morning, with clearing skies expected behind the departing upper- level trough and ridge building over the region. Temperatures will warm nicely on Wednesday, though may be stunted depending on the exact amount of snowfall received, as well as how much of it sticks. Thursday will bring the next upper-level trough through the region, with ample synoptic forcing for another round of precipitation across the region. The 700mb low associated with this incoming trough looks to be positioned a litter further to the north per the GFS and directly overhead per the ECMWF. Both long range models suggest a strong cold front pushing through Thursday, though the ECMWF lags behind the GFS by almost 24 hours with bringing the front through the region. Therefore, Thursday's temperatures forecast is low confidence at this time, due to significant differences in frontal passage in longer range models. Despite this, the cold front should be strong enough to bring another round of beneficial precipitation to the entire CWA. Given very cold 700mb temperatures expected behind the front, any rain falling on Thursday should very quickly transfer over the snow and continue through potentially early Saturday morning. This event is several days out at this time, but it will be something to watch as this first system pushes through the region. Cooler temperatures expected to end the week before a warming trend returns for the weekend.

AVIATION /06Z TAFS THROUGH 06Z MONDAY/

Issued at 1040 PM MST Sat Feb 28 2026

Mid to upper level cloud cover will be increasing overnight across the area. RWL and LAR may see some showers in the area, which will have about a 30% chance to produce brief MVFR conditions at RWL during the early morning hours. Nebraska panhandle terminals will be dealing with some LLWS concerns overnight as strong SSW winds are persisting overtop lighter SE winds at the surface. Stronger gusts breaking down to the surface cannot be ruled out.

Cloud cover will thin temporarily during the day Sunday, but expect this to increase again in the late afternoon with scattered showers developing. Temperatures should be warm enough to support mainly rain as the precipitation type at ground level, but brief MVFR CIGs will be possible.

CYS WATCHES/WARNINGS/ADVISORIES

WY...None. NE...None.