textproduct: Cheyenne

KEY MESSAGES

- The High Wind Warnings has been expanded to include the Interstate- 80 Summit and Foothills from 3 AM this morning until noon this afternoon.

- 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 213 AM MDT Wed Apr 8 2026

High clouds are slowly filtering in across western portions of the CWA this morning, with clear skies east of I-25. A weak cold front is visible on low-level water vapor imagery tonight across far northern portions of the CWA along a line from about Douglas eastwards through Lusk. Temperatures behind the front are around 10 to 15 degrees cooler than out ahead of the front, with stout northerly winds. This front will continue moving southward through the morning hours, briefly turning out winds northerly and leading to a slightly cooler day today, but minimal precipitation chances. Very gusty winds are ongoing across the Arlington/Elk Mountain wind prone area this morning, with gusts between 58 and 60 mph ongoing. Strong winds may develop across the I-80 Summit and Foothills later this morning due to subtly increasing height gradients at 700mb. Therefore, the High Wind Warning was expanded to include the I-80 Summit and Foothills from 3 AM through noon today. The cold front should act to limit high wind duration later this morning into the afternoon hours.

The cold front slowly moving across this region today is associated with an upper-level low over southern Canada with impressive vertical stacking and strong cyclonic vorticity advection at 500mb. The front looks to be through the entire CWA by 9AM this morning, with northerly winds behind it. However, the 700mb low is progged to wiggle southwards through the morning hours today, leading to increasing 700mb height gradients across the CWA and westerly flow along and west of the Laramie Range. East of the Laramie Range, winds will start northerly, before flipping easterly as a diffuse surface low over Colorado attempts to develop and the region is placed within the easterly flow found in the northern sector of the surface low. As a result, stout, upslope flow is expected along the I-80 corridor this afternoon and evening. Despite the favorable upslope flow, moisture across the area is noticeably lacking. Forecast soundings from the RAP suggest an impressive Inverted-V signature for much of the I-80 corridor. Therefore, virga showers may develop today, but one again little to no precipitation is expected to reach the surface. These showers may produce gusty and erratic winds this afternoon. Kept about 15 to 20% PoPs in the forecast to highlight the potential for highly isolated virga showers, but minimal precipitation is expected near the surface. Highs today will be in the mid-50s to mid-60s behind the weak cold front this morning with partly cloudy skies, leading to another pleasant day across the region.

Zonal flow returns to the region for Thursday as a broad, flat trough moves across central Canada. An upper-level low just west of California will slowly meander eastward, though it is currently expected to stall briefly throughout the day Thursday as a weak ridge attempts to develop out ahead of the trough. Isolated lobes of 500mb vorticity will eject out of the trough out west across the CWA Thursday evening, leading to isolated synoptic ascent for portions of the area. 700mb flow remains largely light and zonal for Thursday as the 700mb system moves off to the east by late Wednesday night/early Thursday morning. Warm air advection will develop for Thursday morning and afternoon, mainly along and east of the Laramie Range, leading to warmer temperatures and increasing synoptic ascent. A secondary, weak cold front will move through Thursday evening, allowing for more focused synoptic ascent for much of the area. Northerly flow will develop once again on the backside of the front, leading to cooler temperatures Thursday night into early Friday morning. With the incoming front, combined with warm air advection through the early afternoon hours, multiple vorticity maxima moving across the region, and improving PW values, more precipitation is possible Thursday afternoon through the evening hours. However, forecast sounding from the RAP continue to suggest Inverted-V profiles, suggesting a higher potential for dry microbursts and evaporating precipitation. Therefore, more is a relative term, as a few hundredths is more than nothing, but a drought busting event is not anticipated with the setup. Temperatures Thursday afternoon will climb into the mid-60s to mid- 70s before the weak cold front pushes through and cools temperatures back into the 20s and 30s Thursday night into Friday morning.

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, leading to PW values increasing towards the 99th percentile for this time of year, per the NAEFS Mean Precipitation Water Climatology. 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 into the day Saturday (more on this in the long term discussion below). 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 the area. Temperatures will only increase into the mid-50s to mid-60s, with the coolest temperatures east of the Laramie Range where the cooler, upslope flow will be ongoing as well as increasing cloud coverage with the increased moisture and upslope flow.

LONG TERM /SATURDAY THROUGH TUESDAY/

Issued at 213 AM MDT Wed Apr 8 2026

Saturday has the potential to be the most active day of the forecast period, with concerns for strong to severe storms increasing. Upper- level flow will remain largely southwesterly as the upper-level ridge continues to move eastward as the upper-level trough approaches from the west. As the trough continues to push through, it is anticipated to take on more of a negative tilt through the early afternoon hours Thursday. Much of the CWA will be in the left exist region of the upper-level jet, suggesting increased synoptic ascent. Additionally, strong cyclonic vorticity advection is anticipated as multiple vorticity maxima eject out ahead of the approaching trough. A weak, 500mb shortwave will attempt to develop with the increasing CVA across the area, leading to additional synoptic ascent as the shortwave digs across. 700mb flow showers a very similar story, with stout southwesterly flow increasing through the afternoon and evening hours, with a shortwave trough developing later into the evening, increasing height gradients and increasing the 700mb jet. WAA is expected to continue Friday night through much of the day Saturday, favoring lower-level support for ascent and warming temperatures into the mid-60s to mid-70s, with the warmest temperatures across the Nebraska Panhandle. With stout, southwesterly flow ongoing for multiple days as the upper-level trough digs across the CONUS, PW values are expected to increase past the 99th percentile for this time of year, especially across the Nebraska Panhandle. With strong synoptic support, as well as ascent in the lower-levels, isolated to scattered showers and likely thunderstorms are anticipated to develop across areas east of the Laramie Range, with just isolated showers west. As of now, the GFS suggests around 500 to 600 J/kg of SBCAPE Saturday afternoon in the Panhandle, with forecast soundings suggesting good directional shear throughout the lower-level of the atmosphere. Therefore, an isolated strong thunderstorm could be possible across the Panhandle, with the main threat likely being strong winds and possibly large hail. This event is still several days out, but it will be interesting to see what the HIRES models start suggesting as Saturday comes into their domain. It will definitely be a day to watch for the first potential strong to severe thunderstorm day of the 2026 Severe Season.

The remainder of the long term forecast will mainly feature the upper-level trough slowly pushing through the region and daily, isolated to scattered, precipitation chances across the region. The upper-level trough is expected to depart from the region by mid- week, with much cooler temperatures looking to return. Tuesday will be the coolest day as the upper-level trough moves directly overhead and cooler air flow into the region. However, there is some significant disagreement between the GFS and ECMWF on exactly what will cause the coolest temperatures Tuesday. The GFS suggests a strong, Colorado Low bringing rain and snow back to the region throughout the day Tuesday, while the ECMWF suggests just cooler air associated the the trough leading to the cooler temperatures on Tuesday. The GFS solution would give the CWA more precipitation with stronger bands possible, while the ECMWF suggests lower precipitation totals will less intense bands. This potential system will need to be monitored, especially with the differences currently seen in the longer range models.

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.

CYS WATCHES/WARNINGS/ADVISORIES

WY...High Wind Warning until 3 PM MDT this afternoon for WYZ110. High Wind Warning until noon MDT today for WYZ116-117. NE...None.