textproduct: Cheyenne

KEY MESSAGES

- Breezy winds will continue behind a passing cold front this morning into the afternoon hours.

- Temporary relief from the critical fire weather conditions expected this weekend behind the cold front Saturday and a secondary cold front moving through Sunday.

- Fire weather concerns increase significantly Monday through at least Friday, with dry, breezy conditions and very warm temperatures. Minimal precipitation expected at this time.

SHORT TERM /THROUGH SUNDAY NIGHT/

Issued at 143 AM MDT Sat Jun 13 2026

A weak, upper-level low will slowly traverse across Montana and northeastern Wyoming today, bringing a strong cold front through the CWA. The upper-level low looks to stall across eastern Montana before being largely absorbed into the upper-level flow by Saturday afternoon. 700mb flow suggests the 700mb front pushing through the region in the late morning to early afternoon hours, with surface flow also suggesting the front to move through in the late morning to early afternoon hours. However, this front may stall somewhere across the Laramie Range, leading to meager precipitation chances for northern portions of the region (northern Converse and Niobrara Counties), while the rest of the CWA is able to warm back into the 60s and 70s. Breezy winds are expected as the front passes, with very strong surface pressure gradients expected north to south across the CWA due to the development of a stout surface high across northern Wyoming. Reverse pressure gradients will lead to northerly to northeasterly winds around 20 to 25mph with gusts up to 40+mph. The Arlington wind prone area may see elevated winds with gusts over 50mph possible, due to the stout reverse surface pressure gradient across the region, but high winds are not anticipated. Thankfully, the front will improve humidity across the region, leading to afternoon minimum humidity values remaining in the 30 to 45 percent range for much of the region, with 20 to 25 percent possible across Carbon and Albany counties. Fire weather concerns will be lesser today than previous days, due to the cooler temperatures and increasing humidity values.

Sunday will feature a similar situation to Monday, with a weak, upper-level low, but this low is anticipated to strengthen across the Intermountain West. As this low deepens just to the north of the CWA, strong zonal flow will develop aloft. However, strong cyclonic vorticity advection just downstream of the upper-level trough axis will lead to the low becoming a strong, short-wave trough with a decent positive tilt. This orientation does not change much for the region, but northwesterly flow will develop briefly before the short-wave moves off the the east far enough that zonal flow returns to the region once more. A stout ridge slowly develops off the West Coast, resulting in northerly flow late Sunday night into early Monday morning across the region. A second cold front moves across the region as the upper-level shortwave pushes through. This front will drop 700mb temperatures significantly, with locations east of the Laramie Range seeing 700mb temperatures around the -1 to 3C range, while west of the Laramie Range remains warmer in the 4 to 6C. As a result, temperatures will be in the 60s to low-70s everywhere. Sunday morning after the secondary front, surface flow turns easterly as the front gets hung up on the Rockies and brings the front back westward. With increasing humidity and dew points behind the cold front and decreasing temperatures, fog may be possible along and just east of the Laramie Range as moist, upslope flow continues during the very early morning hours. The fog should clear through the early morning hours, just in time for isolated rain showers to develop along and east of the Laramie Range. This looks to be the best chance at precipitation for the next several days, but will be a fairly localized area. Drier conditions return for the evening hours as easterly, upslope flow weakens.

LONG TERM /MONDAY THROUGH FRIDAY/

Issued at 143 AM MDT Sat Jun 13 2026

Monday onwards will largely be dominated by stout, upper-level ridging across the western CONUS. Dry, northwesterly flow aloft develops Monday morning and continues through at least Friday morning. 700mb temperatures will skyrocket into the 12 to 16C range by Tuesday evening, with temperatures remaining in this range through at least Friday, with a temporary break Thursday. With increased subsidence across the region from the upper-level ridge and very warm 700mb temperatures, a hot week is in store for southeast Wyoming and western Nebraska. Daily high temperatures will largely remain in the 80s to 90s, with the warmest day looking to be Friday at this time, with Wednesday not too far behind. Unfortunately, very dry conditions are expected, with minimum afternoon humidity values dropping well into critical levels each day this work week. Winds will remain breezy through the week, with the potential for high winds in the wind prone locations Wednesday. With little to no precipitation expected, hot, dry, and windy conditions are anticipated daily, leading to increasing fire concerns through the week. Precipitation looks to return Friday evening, but most of the week will be dry and warm.

AVIATION /12Z TAFS THROUGH 12Z SUNDAY/

Issued at 501 AM MDT Sat Jun 13 2026

Mostly clear skies this morning across KCYS, KLAR, KRWL, and KSNY, while KBFF, KCDR, and KAIA are seeing some low clouds move over the terminals. Lower clouds look to stick around for the next 2 to 4 hours before clearing out and/or lifting. Gusty winds return this afternoon with many terminals seeing northerly to northeasterly winds gusting 25 to 30kts. Winds start to decrease late this evening, with lower ceilings moving back into the region and more easterly winds returning.

CYS WATCHES/WARNINGS/ADVISORIES

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