textproduct: Cheyenne

KEY MESSAGES

- Red Flag Warning in effect for Converse and Niobrara Counties.

- Warming and drying trend expected through the end of the week.

- Precipitation chances return for the beginning of next week.

SHORT TERM /THROUGH TONIGHT/

Issued at 327 AM MDT Thu Sep 3 2026

Looking at Mid-level water vapor, there are two low pressure systems over the pacific northwest and adjacent Canadian Provinces. As the ridge starts to retrograde to the west, it is pushing these systems further north into the Canadian Provinces. This ridge will increase the height gradient between the systems in the Pacific Northwest and the ridge, causing breezy conditions tomorrow. The dry air mass currently sitting over eastern Colorado/western Kansas will be advected northward into our region. This dry air mass will limit the amount of available moisture over the region and drop afternoon dewpoints into the low teens and single digits. A red flag warning was issued for Converse and Niobrara County as the breezy winds will overlap with the lower dewpoints for the required 3 hours. Platte and Goshen County could also have red flag conditions however it was uncertain if the stronger winds would last the required minimum of 3 hours before the ridge cuts off those breezy winds. Warmer temperatures are to be expected today and Friday with minimal to no shower activity as the convective temperature remains in the mid 90s according to the model soundings. The more mountainous areas can expect to remain breezy today and tomorrow as the gradient will remain rather compressed over that area. But areas east of the I-25 corridor can expect the winds to be lighter Friday than they would be this afternoon. High-res models show little to no CAPE over our forecast area for today and Friday adding higher confidence that the dry air mass will be advecting over our area and cutting off the moisture supply.

LONG TERM /FRIDAY THROUGH WEDNESDAY/

Issued at 201 PM MDT Wed Sep 2 2026

Saturday...Southwest flow aloft prevails. Looks like with a minor stream of the monsoonal moisture tap, we anticipate isolated to widely scattered showers and thunderstorms in the afternoon and evening.

Sunday...The precipitable water values increase somewhat as monsoonal moisture increases. With that said, expect scattered afternoon showers and thunderstorms to form over and near our Snowy Range and Laramie Range in the afternoon due to orographic effects and differential heating, with most of the convection propagating over the Nebraska Panhandle in the evening.

Monday...Somewhat drier air aloft moves overhead under southwest flow aloft, which should correspond to an areal decrease in afternoon and evening showers and thunderstorms.

Tuesday and Wednesday...Again, somewhat drier air infiltrates our western counties using precipitable water values, with a bit better moisture further east, thus isolated to scattered showers and thunderstorms expected mainly over the mountains and eastward.

AVIATION /12Z TAFS THROUGH 12Z FRIDAY/

Issued at 514 AM MDT Thu Sep 3 2026

Clouds will start to clear out through the morning. Winds are expected to pick up around 15z for most locations and then back off around 23z for the Nebraska sites and around 02/03z for the Wyoming sites. No showers are currently anticipated for this afternoon and evening as an upper level ridge starts to push into the region. A few high based clouds may push through the area but that is about it for today.

CYS WATCHES/WARNINGS/ADVISORIES

WY...Red Flag Warning from noon today to 7 PM MDT this evening for WYZ417-418. NE...None.