textproduct: Cheyenne

KEY MESSAGES

- Multiple, weaker cold front will push through over the next couple of days, leading to slightly cooler temperatures and increasing precipitation chances heading into the weekend.

- The first strong thunderstorms could arrive as early as Saturday afternoon to the western Nebraska Panhandle.

SHORT TERM /THROUGH FRIDAY NIGHT/

Issued at 254 PM MDT Wed Apr 8 2026

Looking at Mid-level water vapor, the upper level low that was traversing across the Canadian providences is now slowly diving south into the Northern Plains. As this kind of wobbles along the Canadian/US border, a stream of vorticity will push through our CWA later tonight. This vorticity will help develop some light showers with the increased synoptic lift however, looking at the QPF fields and model soundings very little precipitation is expected to reach the ground if any at all. The probabilities were kept at 15 percent or less with the greatest chance for 0.01 inches being around Chadron tonight at a whopping 20 percent. Another shortwave or broad trough will pass through the Canadian providences Thursday turning our winds more westerly. These westerly winds will put us in a dry downslope regime. Model soundings show the mid to upper levels becoming saturated but the lower levels remain quite dry. Winds will be light in the morning and gradually increase Thursday afternoon. While high winds aren't expected, the winds will be strong enough to reinforced that dry layer near the surface severely limiting the amount of precipitation if any to reach the surface. This broad trough will put up a good fight as multiple lobes of vorticity combined with the increased mid-level moisture and warm air advection (WAA) to increase the synoptic forcing to provide a fighting chance for some precipitation Thursday afternoon and increasing chances later that evening. Currently the greatest chances for precipitation for the region lies near the Wyoming Colorado border and the Sierra Madre mountains as the westerly winds create a favorable upslope enhancing the chances for precipitation for the mountains. A cold front is progged to transit through the forecast area Thursday evening into the overnight hours. With the cold front passing through the later portion of the day, the atmosphere will have begun to saturate due to the falling temperatures and thus provide more moisture parcels to be lifted by the front. POPs were gradually increased throughout the afternoon and into the overnight period to reflect this. Southwesterly flow is anticipated to return for Friday afternoon as the upper-level trough starts to push into the West Coast and digs across central and southern California. The weak, upper-level ridge will start to push into the CWA late Friday morning with the apex of the ridge moving through by the early afternoon hours. Once the apex moves through, southwesterly flow returns on the western side of the ridge. With the strong trough across the West Coast, southwesterly flow across the CWA will act to advect in pacific moisture, with NAEFS to show mean PW values to be in the 90-97th climatological percentile across Southeast Wyoming and the western Nebraska Panhandle area. Multiple 500mb vorticity lobes will eject out ahead of the approaching trough, favoring increasing synoptic ascent across the CWA for Friday afternoon and evening. 700mb warm air advection will increase significantly Friday morning into the early afternoon hours, with even stronger WAA expected overnight Friday. With a surface high over Minnesota and lower pressure west of the Rocky Mountains, a strong surface pressure gradients will develop, leading to easterly winds as wind flow from the higher pressure towards the lower pressure. As a result, moist, upslope flow is expected east of the Laramie Range, increasing precipitation chances once again. Isolated to scattered showers and potentially a rumble or two of thunder is expected throughout the afternoon and evening on Friday. Once again, this does not look to be a drought busting event, but another 0.03 to 0.10 in of precipitation is possible across most of the area.

AVIATION /18Z TAFS THROUGH 18Z THURSDAY/

Issued at 1142 AM MDT Wed Apr 8 2026

Mainly a wind forecast for the upcoming TAF period. At all terminals except RWL, winds will veer through nearly the entire compass over the next 24 hours. North to northeast winds this afternoon will turn east and then southeast overnight. A brief surge of southerly winds is expected Thursday morning, before winds flip back to the west or northwest near the end of the period.

In addition, some isolated virga showers late this afternoon through the evening may lead to brief gusty and erratic winds. VIS or CIG drops are not expected. Expect increasing mid to upper level cloud cover. a few low clouds cannot be ruled out Thursday morning, but the probability (10%) is too low to add to the TAF.

AVIATION /00Z TAFS THROUGH 00Z FRIDAY/

Issued at 530 PM MDT Wed Apr 8 2026

Winds will be all over the compass over the TAF period, especially over the High Plains. Winds will turn east to southeast this evening. Then, expect a brief surge in southerly winds Thursday morning, before winds ease and turn southwest mid morning, and then west to northwest by the early afternoon. Winds finally return back to north or northeast by Thursday evening.

Isolated virga showers may produce some brief gusty winds and a possible sprinkle over the next few hours in Wyoming, with mid to upper level cloud cover filtering through into Thursday. Thursday's shower activity will be more widespread, kicking up mid afternoon. PROB30 groups were introduced for gusty and erratic winds. Rain may actually reach the ground, so a brief VIS/CIG drop and a few rumbles of thunder can't be ruled out on Thursday afternoon and evening.

CYS WATCHES/WARNINGS/ADVISORIES

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