textproduct: Cheyenne

KEY MESSAGES

- A Red Flag Warning is in effect for all areas along and east of the Laramie Range through Saturday evening. Critical fire danger is expected.

- Record warmth will start as early as this afternoon, but more likely to start on Thursday and continue through Saturday.

- Cooler, though still above average, temperatures return Sunday behind a cold front pushing through. Isolated to scattered precipitation chances expected with this frontal passage.

SHORT TERM /THROUGH SATURDAY/

Issued at 149 PM MDT Wed Mar 18 2026

A blustery afternoon continues, especially in the wind prone areas where sporadic gusts over 50 MPH are being observed. A High Wind Warning remains in effect for the Arlington area for occasional gusts to 60 MPH. Cannot rule out a few rogue gusts to 60 MPH in the South Laramie Range as well since winds aloft will be around 50 kts with decent subsidence. Winds will finally ease this evening as 850 and 700 mb height gradients relax. Despite strong winds easing, breezy conditions are still expected overnight across southeast Wyoming.

A strong bubble of high pressure will be in place over the Four Corners region Thursday through Saturday. Over the next three days, temperatures each day will gradually warm a few degrees as the ridge axis slowly meanders eastward. 700 mb temperatures will climb from an already warm +8C on Thursday to a roasty +12C on Saturday. Temperatures this warm are extremely rare and unprecedented, putting them in NAEFS climatological max. High temperatures will be 30 degrees above average, if not a few degrees more. High temperatures both Thursday and Friday will be in the 70s and 80s, with 80 degree temperatures expected for most areas east of the Laramie Range. Most locations are likely to set record highs by Friday, with southeast Wyoming cities expected to set records on both days. The heat wave will peak on Saturday, with some locations hitting the low 90s! On Saturday, it is likely that all climate locations will break daytime record highs, as well as monthly record highs! Due to the strength of the ridge, precipitation is not expected as mostly sunny skies will dominate. The lack of precipitation and dry air under the ridge will lead to critical fire weather conditions through Saturday. The CWA will be within the vicinity of an upper-level jet which will lead to breezy conditions for the duration of the heat wave. Red Flag Warnings are already in effect and will remain in effect through Saturday evening due to the extreme dryness and breezy conditions.

LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/

Issued at 149 PM MDT Wed Mar 18 2026

A shortwave trough passing well to the north of our area will flatten the powerful ridge over the weekend. The upper level system will be followed by a surface high pressure system sliding down into the northern Plains, which will push a cold front through the area Saturday night. While temperatures are expected to drop 20 to 30 degrees from Saturday's highs, Sunday's forecast high is still slightly above average for much of the area, emphasizing the magnitude of this week's warm air event. About 50% of ensemble members have some light rain and snow showers moving through the area with the frontal passage, but this is not expected to provide appreciable rainfall.

The ridge begins to re-strengthen across the western CONUS by early next week, sending temperatures back to values well above average by the end of the forecast period. The second round of warmth should peak around Wednesday of next week, before ensembles diverge wildly beyond. We will also need to watch for the threat for high winds potentially returning around Tuesday of next week. Probabilities are not too high right now, generally around 40%, but with the second phase of this warm spell looking like a little more zonal flow, we will need to watch for winds aloft increasing as it gets closer. NAEFS mean 700-mb winds indeed approach the 90th percentile by the end of the day on Tuesday. Record highs may also creep back into the forecast during this period as 700-mb temperatures push back above the 90th percentile and even close to the 99th percentile on Tuesday into Wednesday.

AVIATION /00Z TAFS THROUGH 00Z FRIDAY/

Issued at 536 PM MDT Wed Mar 18 2026

Low level windshear will be possible for KLAR and KCYS overnight as the 700mb jet will be continuing overnight. Otherwise winds look to pick up in the afternoon for the Nebraska terminals with gusty winds through the night for the Wyoming terminals. Clear skies look to be the predominant sky coverage after this high based clouds push through.

CYS WATCHES/WARNINGS/ADVISORIES

WY...Red Flag Warning until 8 PM MDT Saturday for WYZ417>419- 430>433. High Wind Warning until 6 PM MDT this evening for WYZ110. NE...Red Flag Warning until 8 PM MDT Saturday for NEZ434>437.