textproduct: Cheyenne

KEY MESSAGES

- Red Flag Warnings are in effect for areas east of the Laramie Range through Monday due to dry conditions.

- High Wind Watches in effect for the Arlington area and South Laramie Range late tonight into Monday afternoon.

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

SHORT TERM /THROUGH TUESDAY/

Issued at 221 PM MDT Sun Apr 12 2026

A pleasant day will continue this afternoon with mild, above average temperatures and mostly sunny skies. Fire weather concerns also continue this afternoon with very dry and breezy conditions. However, a shortwave ejecting into northwest Wyoming overnight could bring some minor precipitation chances to areas west of the Laramie Range. Hi-Res models like the HRRR show a few light showers developing in and around the high terrain after 10 PM tonight. Cannot rule out a dusting of snow with these late night showers. This shortwave could also trigger brief high winds after midnight. MSLP gradients aren't great, however, there is a noticeable uptick in both 850 and 700 mb CAG to CPR height gradients late tonight/early Monday morning. 700 mb winds respond to this, ramping up to about 50 kts. Adequate subsidence could be enough to get these winds down to the surface. Given the brevity of this event and marginal signal, issued a High Wind Watch for the Arlington zone and the South Laramie Range. The Watch lasts from midnight tonight through mid-Monday afternoon. The most likely time for high winds will be Monday morning when winds aloft are at their strongest.

The blustery conditions expected Monday will contribute to the ongoing critical fire weather conditions. Dry conditions east of the Laramie Range will persist at least through the afternoon hours as dry desert air continues to be advected out of the southwest. The downslope regime from the high winds will also add to the dryness, hence the Red Flag Warning already in place for tomorrow afternoon. Besides the wind and fire weather concerns, the shower threat will continue out west throughout much of the day. As the previous shortwave exits Wyoming, another one will takes its place, keeping enough vorticity present in order for scattered showers to develop. Light snow accumulations can also be expected in the mountains during this time.

Precipitation chances on Tuesday will increase across the entire forecast area. An even larger trough will swing into the Rockies, bringing ample moisture with it. Hi-Res guidance shows precipitation moving into the Interstate 80 corridor early Tuesday morning, and spreading northeastward throughout the day. Modeled QPF amounts exceed a few tenths in some locations, meaning this could be a decent precipitation event to help combat some of the dryness this past season. The mountains are also likely to pick up a few inches of late season snow, however accumulations at this point look sub- Advisory.

LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/

Issued at 221 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 /00Z TAFS THROUGH 00Z TUESDAY/

Issued at 520 PM MDT Sun Apr 12 2026

VFR conditions will remain in place throughout the TAF period with WSW flow ranging from 20 to 25 knots for our Wyoming terminals. KRWL will see gusts up to 40 knots before briefly relaxing until 09Z. All our Nebraska and Wyoming terminals will see an increase in gusts after daybreak and are expected to gust up to 45 knots, while the Nebraska terminals will be slightly calmer gusting from 35 to 40 knots. Scattered to broken clouds at or above 18 kft are anticipated throughout the period with no low ceiling/visibility concerns.

CYS WATCHES/WARNINGS/ADVISORIES

WY...Red Flag Warning until 8 PM MDT Monday for WYZ417>419-430>433. High Wind Watch from midnight MDT tonight through Monday afternoon for WYZ110-116. NE...Red Flag Warning until 8 PM MDT Monday for NEZ434>437.