textproduct: Cheyenne

KEY MESSAGES

- Hot, dry and breezy conditions expected through the end of the week.

- Monsoon flow in the long term intensifies, lowering our afternoon highs and increasing rain chances.

SHORT TERM /THROUGH THURSDAY NIGHT/

Issued at 124 AM MDT Wed Jul 15 2026

Hot and dry conditions are expected to continue for the foreseeable future as a stout, upper-level ridge remains firmly in place across the CONUS. The 500mb ridge remains largely unchanged for the next couple of days, though the 595dm 500mb high across the East Coast attempts to stretch northwestward towards the region. Luckily, if that is even the proper term, this high should remain just to our east with a "measly" 591dm high across the Intermountain West. There are some hints at the monsoon attempting to develop, though much of the moisture looks to remain well south of the CWA for the next several days. Unsurprisingly, 700mb temperatures will remain in the 12 to 15C range Wednesday, with Thursday starting to see 15 to 20C temperatures returning to the region. As a result, surface temperatures will rise back into the upper-80s to low-100s once again both Wednesday and Thursday, and likely most days through the weekend as well. Mostly clear skies will persist under this strong ridge, leading to sunny, hot, and dry conditions. Little to no precipitation is expected outside of the mountain for the next two days, with the mountains only seeing a slight chance (~15%) for precipitation Thursday afternoon. However, less than 0.01in of precipitation is possible for the mountains Thursday. "Better" precipitation chances return towards the end of the week into the weekend, but still remain rather low. Winds will remain fairly breezy today and Thursday, leading to slightly "cooler" highs for the Cheyenne area due to cooler, southerly flow from upslope along the Cheyenne Ridge. However, the Heat Advisory remains in effect through midnight tonight, as overnight lows only drop into the mid- 50s to mid-60s tonight and mid-50s to low-70s Thursday morning. Extensions may be needed for the Heat Advisory, but will let the daytime shift take another look. With hot, dry, and breezy conditions, the Red Flag Warning remains in effect through the day today. Slight humidity improvements are possible Thursday afternoon, though elevated fire conditions are still expected.

LONG TERM /FRIDAY THROUGH TUESDAY/

Issued at 124 AM MDT Wed Jul 15 2026

No major chances, please see previous forecast discussion...

The ridge is still dominating the weather at the start of the long term, though it appears that it will be weakening slightly compared to what it was this past weekend. A retrograding cut off low to our south will lower dam heights overhead and elongate the ridge axis. Monsoonal moisture streaming in on the western edge of the ridge will reach the area and may promote a few showers and storms, particularly for higher elevations near the Snowy and Sierra Madre Ranges and points west. The mean flow will cause storms to drift southwest. High temperatures in the 90s to low 100s and clear skies are most likely for the majority of us. Humidity values will be low for most of the area, but thankfully winds will not be very strong and values don't stay below 15 percent long enough to warrant a red flag warning at this time. However, conditions would suggest elevated fire concerns.

This type of pattern holds for the next few days. The ridge builds slightly as the upper level low slowly decays well to our south. Daily afternoon showers and storms in the mountains and western counties of our CWA are possible. Temperatures climb slightly each day with more places hitting the 100s east of I-25, with Saturday and Sunday appearing to be the hottest days. Elevated fire weather continues.

The monsoonal flow continues to be advected north from the Pacific Ocean during this time. Interestingly our weather could be influenced by tropical cyclone activity starting Monday. A disturbance is forming in the East Pacific which could mature and move northwest ahead of upper level troughing off the west coast. Moisture from this cyclone would then be channeled north in this troughing flow and add to the monsoon. This is dependent on the track of the future system and would only impact the available moisture content of the monsoon and jet positions for our area. The deterministic GFS is producing widespread PWATs of above 1 inch starting Monday. While an imperfect proxy to gauging the magnitude of this moisture, we turn to the Riverton PWAT climate for this period. The maximum measured PWAT for this time is between 1.10 and 1.20 inches. The GFS is giving PWATs of 1.10 inches for the Rawlins area. So in other words the atmosphere will be holding an anomalously high amount of moisture. Storms and showers chances naturally increase with all this ambient moisture. Some of these storms could produce heavy rains. The WPC has marginal excessive rainfall outlooks for areas west with the current monsoonal flow, so it would not be that far of a stretch that future outlooks cover our area as well for this period. With increasing moisture the extra cloud coverage will keep afternoon temperatures in check with hopefully most locations staying below 100. This moisture is expected to linger into Tuesday, so much the same weather can be expected then.

AVIATION /06Z TAFS THROUGH 06Z THURSDAY/

Issued at 945 PM MDT Tue Jul 14 2026

Upper level high will drift eastward over the next 24 hours allowing some moisture to move into the area on Wednesday and later in the week. Winds will remain out of the south to southeast over the next 24 hours.

HAZARDS/WEATHER TRENDS: VFR conditions will continue over all terminals. Gusty south to southeast winds up to 30 knots, mainly between 17z and 02z. Winds will remain gusty at KCDR tonight and likely Wednesday night due to the low level jet.

CYS WATCHES/WARNINGS/ADVISORIES

WY...Red Flag Warning until 8 PM MDT this evening for WYZ417>420- 423-427-430>433. Heat Advisory until midnight MDT tonight for WYZ101-102-107- 108-118-119. NE...Red Flag Warning until 8 PM MDT this evening for NEZ434>437. Heat Advisory until midnight MDT tonight for NEZ002-003- 019>021-054-055-095-096.