textproduct: Cheyenne

KEY MESSAGES

- Red Flag Warnings continue for areas east of the Laramie Range through this afternoon due to gusty winds and dry conditions.

- High Wind Watches remain in effect for the Arlington area and South Laramie Range into this afternoon.

- Precipitation chances increase Tuesday through the end of the week with the threat of thunderstorms and snow.

SHORT TERM /THROUGH TUESDAY NIGHT/

Issued at 202 AM MDT Mon Apr 13 2026

Enjoy those mostly sunny skies and above normal temperatures for the daytime hours today because changes are in store Monday night into Tuesday, more on that in a bit. Rinse and repeat, fire weather concerns continue into this afternoon as conditions remain very dry along with gusty winds. A shortwave that slid across the CWA tonight may kick start high winds over the next several hours and persist through 3pm this afternoon for the Arlington and South Laramie Range zones. Dynamics are meager at best, but there is enough of a signal to keep the High Wind Watch out that was issued yesterday for said zones. Winds at 700mb ramp up to around 50 knots through the morning hours, and with enough subsidence aloft, per GFS, these winds may mix down to the surface. In-house guidance indicates a 60 percent chance of high winds, with the peak of high winds later this morning for the areas of concern, mentioned earlier, along I-80.

Switching gears to the ongoing fire weather concerns. Southwest flow aloft and a lee-side trough, east of the Laramie Range, will keep winds gusty into the Nebraska Panhandle. This along with an abundance of dry fuels has influenced the SPC to introduce an area of critical fire weather concerns across eastern Wyoming into the Nebraska Panhandle through this afternoon. This area aligns nicely where west to southwest winds 15 to 20 mph, gusting up to 35 mph, will occur along with min RH values dipping down to 8-12 percent. Therefore, the Red Flag Warning that is out will continue through 8pm this afternoon. Locations west of the Laramie Range will escape the fire weather threat as isolated showers are possible for most of today, which is depicted nicely by hi-res guidance. Another shortwave will rotate in over western portions of the CWA, this will keep chances of showers in the forecast, snow at higher elevation (above 7K feet), Monday night through Tuesday.

Speaking of Tuesday, a 500mb trough and vort max will slide in and cross the region through the day, this will spread precipitation chances east into the lower elevations, encompassing most of the CWA. This shows up nicely on the hi-res model suite, with precipitation chances along the I-80 corridor initially and spreading east/northeastward throughout the day. Ensembles show at least a 60 percent chance of a tenth of liquid, which will be a welcomed sign as our CWA has been extremely dry this season. Just like with the precipitation Monday night, the higher terrain may see a few inches of late season snow, not reaching advisory criteria at the moment. Temperatures will be a tad cooler with highs in the 50s west of I-25 and mid 50s/60s east of the corridor. Regarding winds, what winds you'll be saying, as winds for Tuesday/Tuesday night will remain relatively calm.

LONG TERM /WEDNESDAY THROUGH SUNDAY/

Issued at 222 PM MDT Sun Apr 12 2026

The period begins with a departing shortwave trough and building of a weak mid-level ridge downstream of a more amplified trough, which will be the culprit of more active weather later in the week and into the weekend. As a result, mild temperatures will remain in place on both Wednesday and Thursday, followed by an increase in our winds as quasi-zonal 700 mb flow ramps up to 35-40 knots. In-house guidance has 30-40% probabilities of high wind conditions for the usual wind-prone areas starting Wednesday morning before tapering off Thursday night into Friday. While not as impressive as what we have seen in recent, previous events, omega fields continue to show a mountain wave pattern across the Snowy and Laramie Ranges, so will see an increase in our winds during this time at the very least. Ensemble guidance suggests that temperatures will peak in the low to mid-50s west of the Laramie Range, and in the 60s to perhaps 70 degrees east of the I-25 corridor. Thursday is forecast to be our warmest day of the period under warm advection ahead of an advancing cold front that will move across Southern Wyoming and Western Nebraska overnight Thursday into Friday. However if the front and associated surface low trends more progressive, we likely won't warm up as much on Thursday as ensembles are currently showing, as much of our Nebraska counties are showing 50th percentile maximum temperatures in the mid 70s.

Friday will feature much cooler temperatures behind the front, with temperatures dropping a good 20-25 degrees relative to Thursday given strong low-level cold air advection in combination with blustery NNW surface flow. As for any beneficial moisture...don't get your hopes up. Current LREF PWAT percentiles are at or below the 50th percentile for Southeastern Wyoming and Western Nebraska through Friday with ensemble mean QPF at or less than 0.1". The only exception are the Snowy and Sierra Madre Ranges where probabilities of exceeding 0.2" of QPF through Saturday afternoon look to be about 60%. Saturday will again feature below-average temperatures primarily in the 30s and 40s which is running around 15-20 degrees below climatological values. Expect temperatures on Sunday to rebound nicely to at or slightly above seasonal values as a weak mid- level ridge will build in from the west. Dry conditions are expected at this time.

AVIATION /12Z TAFS THROUGH 12Z TUESDAY/

Issued at 525 AM MDT Mon Apr 13 2026

VFR conditions will prevail across all terminals for the duration of this TAF period. Winds will ramp up and become west/southwesterly around 12Z for all sites, with gusts in the range of 30 to 40 knots, possibly higher at times for KRWL and KLAR. Winds will diminish between 00Z and 03Z. Low end precipitation chances at the tail end of this forecast, kept it out of the TAFs due to low confidence.

CYS WATCHES/WARNINGS/ADVISORIES

WY...Red Flag Warning until 8 PM MDT this evening for WYZ417>419- 430>433. High Wind Watch until 3 PM MDT this afternoon for WYZ110-116. NE...Red Flag Warning until 8 PM MDT this evening for NEZ434>437.