textproduct: Cheyenne

KEY MESSAGES

- Cooler temperatures on Saturday alongside some isolated shower or storm chances but remaining weak overall.

- Temperatures warm on Sunday and Monday with increasing precipitation chances, though Monday may see the return of critical fire weather conditions.

- Much cooler on Tuesday with temperatures a few degrees warmer through the end of next week and daily chances of showers and thunderstorms.

SHORT TERM /THROUGH MONDAY NIGHT/

Issued at 145 AM MDT Sat Sep 12 2026

Post-frontal environment will lead to cooler temperatures on Saturday along with another chance of scattered showers and thunderstorms, with temperatures increasing on Sunday and Monday and further shower and thunderstorm chances alongside the return of fire weather concerns by Monday as the surface dries out once again. For today, highs will sit comfortably in the 70's to low 80's for the day. Rawlins will actually be one of the warmest locations for once as the front should be snagged up on the high terrain or lifting just northeast of the area. A weak shortwave should also help to fuel another round of showers and thunderstorms for the day, but with severe parameters lacking not expecting much more than generic precipitation with little in the way of noteworthy activity. Finally, gusty winds expected thanks to the enhanced surface pressure gradient, with westerly winds on the west side of the front, and southerly to southeasterlies east of the front.

Sunday was looking better for stronger to severe thunderstorms, but latest model runs including high resolution guidance are showing a cooler and more stable layer that may inhibit stronger development. The potential is there with some moderate instability and decent wind shear, but even our partners in the SPC have removed the Marginal severe risk we were under. Otherwise, the surface boundary should slowly lift back up as a warm front as a transient ridge moves across, with widespread temperatures back up into the upper 70's to upper 80's for the day. Surface pressure gradients will once again promote breezy to gusty winds, once again split by the boundary as southwesterlies are expected to the west of the Laramie Range and southeasterlies are expected to the east.

Monday a deep upper level Pacific Low will be moving across the US/Canada border with an attendant trough passing through our forecast area. At the surface, another cold front is expected to drop down and move across with another round of precipitation possible but mostly relegated to the I-80 corridor and southward. Severe ingredients are also lacking, so expect general showers and thunderstorms. Temperatures for the day on track to be quite warm, at least east of the Laramie Range with highs in the upper 70's to near 90 degrees for Goshen County and the southern half of the Nebraska Panhandle. West of the Laramie Range meanwhile, the cooler airmass should move across early enough that highs will be limited to the low to mid 70's for the day. This should also be the windiest day of the forecast period, and in-house guidance indicates a 30-40% probability of high wind warnings being needed (gusts 58+ mph). Currently expecting widespread gusts should remain just under the need for products, but as always Wyoming can surprise and will need to keep an eye on how this environment develops. Finally the surface will be quite dry for the day with relative humidity values dropping into the 10-20% range. If this does hold together, a new batch of Red Flag Warnings will be needed, primarily for Southeast Wyoming and looking to remain just outside of Laramie County.

LONG TERM /TUESDAY THROUGH FRIDAY/

Issued at 223 PM MDT Fri Sep 11 2026

Sunday night into Monday morning shows a cold front passing over the CWA. After this front moves out, a ridge starts to build, bringing cooler temperatures and dryer air. Some storm and shower activity is possible Tuesday evening with return flow. A shortwave passes through on Thursday evening, allowing the ridge to continue to build. On Friday the ridge gets pushed out by a trough forming over the region. Some models are showing precipitation potential Friday afternoon, but more to come on that as we get closer. 700mb temperatures are in the 10-15C range in this long term period. Temperatures start to cool off and feel more like fall as the week progresses.

AVIATION /12Z TAFS THROUGH 12Z SUNDAY/

Issued at 534 AM MDT Sat Sep 12 2026

Mostly VFR conditions expected over the next 24 hours. The exception to this would be if any precipitation develops at or moves over TAF sites, which could briefly bring CIGs down or VIS down. Also, some low clouds may move into KSNY/KAIA tomorrow morning, but probs are too low to include at this time. Windy all sites with gusts between 20-35 knots, locally higher near any precipitation and could be erratic. Wind direction will be from the S to W for Wyoming terminals, and from SE for Nebraska terminals. CIGs expected at generally mid levels today, once again lower if precipitation moves over sites, otherwise at SCT through most of the TAF period.

CYS WATCHES/WARNINGS/ADVISORIES

WY...None. NE...None.