textproduct: Cheyenne

KEY MESSAGES

- Red Flag Warning remains in effect through 9 PM Sunday for all of southeast Wyoming for very low humidities and significant gusty winds.

- Elevated to critical fire weather conditions will likely persist into the early work week, with further Red Flag Warnings likely needed each day.

- Hot temperatures continue through the start of the week before a pattern change begins to occur as precipitation chances start to rise and temperatures fall, dropping to below normal by the later half of the week.

SHORT TERM /THROUGH MONDAY NIGHT/

Issued at 200 AM MDT Sun Aug 9 2026

Sunday and Monday will look almost identical to each other as we see the ridge over the Four Corners area flattened by a pair of shortwaves passing across our area each day. Under this pattern, temperatures will be largely similar, with widespread highs in the upper 80's to upper 90's, with a few triple digit highs also possible for our easternmost counties. These warm conditions will help to produce a notably dry surface layer as daytime minimum RH values continue to descend into the teens. Another critical day is expected on Sunday, with Red Flag Warnings remaining in effect through 9 PM. On Monday, we may see a smaller critical environment and a more widespread elevated environment, and overnight recoveries should be much better compared to the past couple of days. Therefore will likely analyze and issue fresh warnings overnight into Monday morning based on what locations can see strong enough winds to go along with the dry surface. Finally, as we saw yesterday, even the high based thunderstorms that we develop can take advantage of their environment. Expect a bit more widespread coverage on Sunday as compared to Saturday, with most storms still remaining gusty virga showers alongside potential dry lightning, but with DCAPE values into the 1500-2000 J/kg range and PWAT values at or just above average, a strong to severe thunderstorm capable of producing some hail alongside the gusty winds cannot be ruled out. Best environment once again will be our easternmost counties into the Nebraska Panhandle. Monday afternoon and evening may be similar in coverage, with CAMs indicating an uptick in potential compared to ensemble guidance. For now, did some slight adjustments to POPs on Monday, and ramped them up dramatically for today, with the same thing likely needed tomorrow night. Because of the dry lower levels though, have kept QPF minimal. Also added plenty of smoke into the forecast alongside our Air Quality Alert valid through Monday, with high resolution guidance showing a clearing into Monday morning but a fresh push of PacNW smoke later in the day.

LONG TERM /TUESDAY THROUGH SATURDAY/

Issued at 256 PM MDT Sat Aug 8 2026

This long-term forecast period will continue a suppressed ridge pattern. The 500mb jet keeps stationed over the PNW and into the Rockies and high plains areas of Montana through northern Wyoming. Precipitation chances increase as the week goes on, with PWAT values increasing daily. Wednesday through Friday looks to be the best chances of precipitation. Severe weather does not appear to be a threat at this time in southeast Wyoming due to mostly light westerly flow in the mid and upper levels. Nebraska on the other hand has better chances of severe weather. As the ridge pushes south and suppresses, faster flow aloft moves in. Wind shear values look to be around 30-40 knots which have the potential to produce multicellular storms. Warm conditions continue through most of this long-term period, but with those precipitation chances mid - end week, temperatures likely will likely be lower than earlier in the week. 700mb temperatures show ranges from the teens to mid-teens, supporting a cooler end of the week. Fire weather will continue to be a concern through Monday with low RHs and some gusty winds. With precipitable water, RHs, RH recoveries, and precipitation chances increasing throughout the week, fire weather concerns fade away.

AVIATION /12Z TAFS THROUGH 12Z MONDAY/

Issued at 531 AM MDT Sun Aug 9 2026

This TAF period brings chances of showers/thunderstorms to all terminals this afternoon. These showers/storms will bring variable, gusty winds between 35-45 knots. Once the showers/storms move out of the area, winds are expected to return to around 15 knots across most terminals, and clouds will mainly be scattered to broken. VFR conditions are expected through this TAF period however, visibility may drop below 3sm under the strongest storms but most of the time should stay around 5 to 6sm.

CYS WATCHES/WARNINGS/ADVISORIES

WY...Air Quality Alert until noon MDT Monday for WYZ101>119. Red Flag Warning until 9 PM MDT this evening for WYZ417>433. NE...None.