textproduct: Cheyenne

KEY MESSAGES

- A Red Flag Warning is in effect for portions of southeast Wyoming and western Nebraska from noon to 9 PM Monday.

- A Fire Weather Watch is in effect for all areas along and east of Interstate 25 from noon Tuesday through 8 PM Wednesday.

- A High Wind Watch has been issued for the typical wind prone regions of southeast Wyoming from 6 PM Tuesday through 3 PM Wednesday.

- Fire weather concerns continue Tuesday through at least Friday, with dry, breezy conditions and very warm temperatures. Minimal precipitation expected during this time.

SHORT TERM /THROUGH WEDNESDAY/

Issued at 147 AM MDT Mon Jun 15 2026

Upper-level ridging will begin to dominate the region starting this morning and continuing through Friday. The upper-level ridge is strengthening over the Pacific Ocean and will move eastward very slowly through the first half of the week. By Wednesday morning, the ridge axis will finally move onshore across the West Coast. Northwesterly flow will continue Monday throughout the week due to the upper-level ridge placement, which favors dry air from Canada to sink into the region most days this week. A 700mb shortwave will push through the Northern Plains and Midwest this evening into early Tuesday morning, likely resulting in increasing winds across eastern portions of the region as a 700mb jet kicks up in association with the passing shortwave. This shortwave will bring a weak cold front through the region early Tuesday morning, but 700mb temperatures rebound quickly and cooler temperatures will likely not be felt Tuesday afternoon. 700mb temperatures Monday will warm into the 5 to 10C range by the afternoon hours, leading to surface temperatures in the mid-70s to low-80s. 700mb temperatures warm quickly into the 13 to 16C range by Tuesday afternoon leading to surface high temperatures in the mid-80s to low-90s everywhere. With subsidence aloft from the ridge, very dry conditions are expected in addition to the warm temperatures, with afternoon humidity values dropping into the 10 to 15 percent range each afternoon Monday through Wednesday. As a result, a Red Flag Warning remains in effect for Monday afternoon and evening, with a Fire Weather Watch in effect from noon Tuesday through 8PM Wednesday evening. Very favorable conditions for rapid fire spread are expected both days.

Wednesday looks to be the most interesting day for the week ahead as a stout 700mb shortwave digs into eastern Montana southeastward through the Upper Midwest. This shortwave will eventually strengthen, becoming a closed low by Wednesday morning. 700mb height gradients across the region will increase in response to the passing and deepening 700mb shortwave, leading to a 55 to 60kt jet Tuesday night into the early morning hours Wednesday. GFS Omega fields suggests ample downward motion along and east of the Laramie Range, as well as near the Snowy and Sierra Madre ranges. Surface pressure gradients will increase Tuesday night into Wednesday morning as the attendant surface low strengthens across central Nebraska, leading to a 3 to 4mb gradient across the Laramie Range and 5 to 6mb gradient across the Snowy Range near Arlington. In-house random forest guidance suggests around a 60% chance for high winds at Arlington/Elk Mountain and the I-80 Summit, with around a 50% chance at Bordeaux. As a result, high winds in the wind prone regions are looking increasingly likely, so a High Wind Watch has been issued from 6 PM Tuesday evening through 3 PM Wednesday afternoon.

LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/

Issued at 147 AM MDT Mon Jun 15 2026

More benign weather returns Wednesday onwards at northwesterly flow continues across the region and the 700mb low responsible for high winds Tuesday into Wednesday moves well out of the region. Temperatures Thursday will likely be the coolest of the weak as cooler air funnels in behind the departing 700mb low. Daytime high temperatures will be in the low-70s to low-80s, with dry conditions continuing. Afternoon humidity values will drop to the 20 to 25 percent range Thursday afternoon, so a brief reprieve from critical fire danger is possible Thursday afternoon. Critical fire danger looks to return Friday as afternoon temperatures warm back into the mid-80s to low-90s once more and afternoon humidity values drop back into the 15 to 20 percent range once again. Little to no precipitation is expected through at least Friday. However, an upper- level trough attempts to develop and move into the western CONUS Friday into Saturday afternoon, potentially bringing widespread precipitation chances to the region and limiting fire danger into the weekend. Long range models are in good agreement with this trough moving through, so a cooler, wetter weekend is likely in store for the CWA.

AVIATION /18Z TAFS THROUGH 18Z TUESDAY/

Issued at 1147 AM MDT Mon Jun 15 2026

Northwest flow aloft will continue to strengthen through the TAF period. Confidence is high that VFR prevails with clear skies. Sufficient pressure gradients will exist, producing wind gusts from 25 to 31 knots through early this evening, then winds will subside after sunset. Wind gusts will again pick up after mid morning Tuesday, with gusts of 23 to 33 knots.

CYS WATCHES/WARNINGS/ADVISORIES

WY...Red Flag Warning until 9 PM MDT this evening for WYZ417-418- 432-433. Fire Weather Watch from Tuesday afternoon through Wednesday evening for WYZ417-418-430>433. High Wind Watch from Tuesday evening through Wednesday morning for WYZ106. High Wind Watch from Tuesday evening through Wednesday morning for WYZ110. High Wind Watch from Tuesday evening through Wednesday afternoon for WYZ116-117. NE...Red Flag Warning until 9 PM MDT this evening for NEZ434>437. Fire Weather Watch from Tuesday afternoon through Wednesday evening for NEZ434>437.