textproduct: Cheyenne

KEY MESSAGES

- Near record warmth and critical fire weather conditions will continue through Monday evening.

- More widespread shower activity expected this afternoon, bringing the potential for gusty and erratic winds and isolated lightning.

- A strong cold front arriving Monday night will bring cooler temperatures and a chance for rain and snow Tuesday into Wednesday.

SHORT TERM /THROUGH TUESDAY NIGHT/

Issued at 100 AM MDT Mon Mar 30 2026

Another warm and dry day is expected today as broad, zonal flow remains in place aloft and 700mb temperatures surge towards the 10C mark this afternoon. Weak, westerly 700mb flow will continue through the afternoon and evening hours, with modest downward omega values across the Laramie Range. As a result, downsloping is expected this afternoon, acting to increase wind speeds at the surface, dry out the lower-levels more, and increase temperatures due to downslope warming. As a result, temperatures today will max out in the mid-70s to mid-80s east of the Laramie Range and mid- to upper-60s west of the Laramie Range. Another day of record temperatures are anticipated, with the question remaining how much will these records be broken by. With downslope drying, afternoon minimum humidities will be in the 10 to 15 percent range everywhere, with winds likely gusting between 40 and 50mph this afternoon. Therefore, the Red Flag Warning will remain in place through the afternoon hours, especially after fairly poor overnight recoveries expected overnight tonight into the early morning hours.

The spell of warm and dry conditions will come to and end, briefly, late this evening into the overnight hours as a cold front moves in from the northwest as a messy surface low pressure system develops across the central plains. Gusty, northerly winds are expected behind this front, as 700mb temperatures quickly drop into the -1C to 1C range by Tuesday afternoon. Temperatures Tuesday will be about 20 to 30F colder than Monday afternoon, with overcast skies expected throughout the day. The initial frontal passage Monday evening will be mostly dry, with some isolated to scattered showers possible across the area, especially in the higher terrain. Hi-Res models suggest SBCAPE values around 50 to 150 J/kg Monday afternoon, so a few lightning strikes cannot be ruled out, but widespread thunderstorms are not expected. The best precipitation chances are not expected until Tuesday evening as a surface low attempts to develop over western Wyoming, turning winds along and east of the Laramie Range to an easterly to southeasterly direction. At the same time, an upper-level shortwave trough is expected to move across the Intermountain West, with a fetch of moisture from the Pacific Ocean. As a result, moist, upslope flow is expected to develop by Tuesday evening and continuing through much of the day Wednesday. As a result, a much cooler and wetter pattern is expected Tuesday through the end of the week, but more details about that in the long term discussion below.

LONG TERM /WEDNESDAY THROUGH SUNDAY/

Issued at 100 AM MDT Mon Mar 30 2026

No major changes. Please see previous discussion for more details...

We remain in an active and cooler pattern into the middle of the week ahead of a dampened shortwave trough embedded in mid-level zonal flow. This will provide a source for ascent and hence chances for beneficial precipitation across Southern Wyoming and Western Nebraska. Models continue to show isentropic ascent throughout this period, in addition to southeasterly anticyclonic upslope flow, which which increases confidence that we will see beneficial moisture from this rather weak wave Wednesday into Thursday. NBM has 60-70% probabilities of exceeding 0.25" of liquid (either in the form of rain and/or snow) through Thursday morning, with odds of 40- 50% of exceeding the same threshold for our Nebraska counties. The LREF has around 20% lower probabilities through this timeframe so there is still some uncertainty which will likely become ironed out in the next couple of days.

As for precipitation type, temperatures look to be borderline cold enough for snow east of the Laramie Range, with 50th percentile temperatures hovering at or slightly above freezing on Wednesday morning and Wednesday high temperatures primarily in the 40s given extensive cloud cover and upslope surface flow. While a mixture of rain and snow seems the most likely, any changes in forecast temperature could result in areas seeing more snow versus rain, or vice-versa.

Thursday is expected to be the warmest day of the period as west- southwesterly 700 mb flow increases to 45-50 knots resulting in a warm, downsloping regime in the lee of the Laramie and Snowy Ranges. Omega fields also show a mountain wave pattern with strong descent in the lee of the aforementioned ranges. This will bring an increase in the high wind threat especially for the favored areas of Arlington and Bordeaux Thursday afternoon into Friday morning. In- house machine learning guidance currently has high wind probabilities(gusts > 58 mph) for both locations around 70-80%. As we know, with wind usually comes the warmth, so high temperatures on Thursday should easily exceed 60 degrees for areas east of the I-25 corridor.

Late Thursday into Friday, a more amplified shortwave trough ejects off to the east, however at this time the bulk of the forcing for ascent looks to remain to our north over South Dakota and NE Wyoming. As a result of the surface low ejecting off the higher terrain and associated lee cyclogenesis to our north and east, a cold front will slice across Southern Wyoming into Friday morning bringing a decrease in high temperatures on Friday and chances for precipitation depending on the eventual track of the lee cyclone. Given ample low-level cold advection behind the front, expect Friday and Saturday's high temperatures to remain 5-10 degrees blow climatology.

AVIATION /06Z TAFS THROUGH 06Z TUESDAY/

Issued at 1104 PM MDT Sun Mar 29 2026

VFR conditions will continue across all terminals for the duration of this TAF period. Winds overnight will not be much of an issue as they remain generally 10 knots or less. However, these calmer conditions wont last long as winds will once again ramp back up in the morning and by 17Z to 21Z, earlier for the Wyoming terminals and a bit later for the Nebraska sites, winds will gust into the 30 to 40 knot range across southeast Wyoming and around 25 knots in the Nebraska Panhandle. By 00Z Tuesday, winds will once again be trending down to less than 10 knots, KRWL may be an exception as winds will remain around 15 knots.

CYS WATCHES/WARNINGS/ADVISORIES

WY...Red Flag Warning until 9 PM MDT this evening for WYZ417>423- 425-427>433. NE...Red Flag Warning until 9 PM MDT this evening for NEZ434>437.