textproduct: Cheyenne

SHORT TERM /THROUGH SATURDAY NIGHT/

Issued at 1230 PM MDT Fri Jul 10 2026

Weather conditions become mostly benign today as high pressure ridging begins to deepen and lift up over the region. For today, a weak surface trough and upslope flow could help to fuel very isolated showers and thunderstorms from the southern Laramie range through Laramie County. However, very dry surface conditions as RH values drop into the mid to low 20% range and inverted V soundings could prohibit precipitation actually making it to the surface by the time activity makes it off the high terrain, fueling a dry thunder and gusty shower/virga threat. Otherwise, the start of our very warm period begins as temperatures rise into the 80's to mid 90's today.

And tomorrow as the ridge continues to build in, temperatures rise further with highs in the widespread upper 80's to upper 90's, with a few locations possibly already peaking into the triple digits. Another surface trough may once again be the focal point for the atmosphere to attempt creating convection, and high resolution model guidance does try to produce some sort of initiation off this feature, but the inverted V feature will be even deeper on Saturday, so the chance of virga actually making it to the surface tomorrow feel slim to none. Instead we'll likely just get another round of gusty conditions from these attempts at precipitation. Finally, heat advisories are in effect beginning tomorrow for locations along and east of the I-25 corridor, and will continue into early next week as temperatures rise through Monday. A fire weather watch is also in effect for our far southwestern zone in Carbon County where fuels are critical, as well as for our Wyoming zones and the northernmost Nebraska zone as winds will begin to pick up tomorrow and continue to gust alongside the dry conditions through early next week.

LONG TERM /SUNDAY THROUGH THURSDAY/

Issued at 1230 PM MDT Fri Jul 10 2026

Sunday through Thursday...Primary challenges will be the heat and fire weather conditions. A 5980 dekameter 500 mb ridge lies over Wyoming Sunday morning, moving to the northern Great Planes Monday morning, and then remains entrenched across the northern Rockies and northern Great Planes through the period. Models suggesting typical monsoonal moisture creeping into our counties Wednesday through Friday with weak perturbations and some mid level moisture to spark isolated to widely scattered thunderstorms over and near the Snowy and Sierra Madre Ranges, as well as the Southern Laramie Range and Laramie Valley from Wednesday through Friday, with coverage of storms slowly increasing through that aforementioned period.

Ridging aloft dominates our region, with quite dry air at low and mid levels, accompanied by typically toasty 700 mb temperatures, thus chances for late day showers and thunderstorms will be nearly nil and non existent, and dry weather will prevail through Tuesday.

The 700 mb temperatures will yield maximum temperatures mainly in the 90 to 105 degree range. Weak perturbations and a slight increase in mid level monsoonal moisture may spark isolated high based thunderstorms on Wednesday, and moreso on Thursday and Friday, again dependent on how much mid level monsoonal moisture advects into our CWA, County Warning Area.

AVIATION /18Z TAFS THROUGH 18Z SATURDAY/

Issued at 1152 AM MDT Fri Jul 10 2026

Ridging aloft will bulge over the forecast area through the TAF period. However, low level convergence along and near the I-25 corridor will produce isolated to widely scattered showers and thunderstorms near the KLAR and KCYS sites from late afternoon through early evening, in close proximity to the 850/700 mb theta-e ridge axises and low level convergence.

Wyoming TAFS...VFR prevails. High confidence in isolated to widely scattered thunderstorms developing near the KLAR and KCYS sites late this afternoon and early evening, per the consistent HRRR hourly runs. Went with PROB30s at Laramie and Cheyenne from 23Z to 02Z, with relatively steep dry adiabatic lapse rates aiding in downward transport of wind gusts to 30 knots from some gusty showers and high based thunderstorms. As always near thunderstorms, expect turbulence, wind eddy effects and gusty and shifting winds. Nearly clear skies at Rawlins. At all sites, skies will clear quickly this evening, with as usual, gusty mix down and gradient winds until sunset, and after 15Z Saturday.

Nebraska TAFS...Clear skies prevail. High confidence in a few high based CU, cumulus clouds developing, but no showers or thunderstorms. Gusty mix down and gradient winds until sunset, and again after 15Z at Alliance and Sidney.

CYS WATCHES/WARNINGS/ADVISORIES

WY...Fire Weather Watch from Saturday afternoon through Sunday evening for WYZ417-418-423-430>433. Heat Advisory from noon Saturday to 9 PM MDT Monday for WYZ101- 102-107-108-118-119. NE...Fire Weather Watch from Saturday afternoon through Sunday evening for NEZ434. Heat Advisory from noon Saturday to 9 PM MDT Monday for NEZ002- 003-019>021-054-055-095-096.