textproduct: Cheyenne

KEY MESSAGES

- A Red Flag Warning is in effect for all areas along and east of the Laramie Range through Saturday evening. Critical fire danger is expected.

- Record warmth will start as early as this afternoon, but more likely to start on Thursday and continue through Saturday.

- Cooler, though still above average, temperatures return Sunday behind a cold front pushing through. Isolated to scattered precipitation chances expected with this frontal passage.

SHORT TERM /THROUGH FRIDAY/

Issued at 1219 AM MDT Wed Mar 18 2026

Stout, upper-level ridging remains in place through much of the week as a closed, upper-level high over the southwestern CONUS builds and remains nearly stationary through the end of the week. 500mb temperatures are expected to soar to above the 99.5th percentile through Sunday morning, per NAEFS Mean Temperature Climatological Percentiles. 700mb temperatures will soar into the +8C to +10C range by this afternoon and continuing through Saturday. These temperatures are above the 99.5th percentile per NAEFS Mean Temperature Climatological Percentiles, leading to strong support for well above average to record breaking heat starting as early as this afternoon, though more likely to start Thursday afternoon when 700mb temperatures surpass the 99.5th percentile. The biggest question with this heat will be exactly how warm it gets, as we still do not have nearly as much daylight hours as the summer months. Additionally, skies will be largely clear, but some clouds make sneak into the area and potentially decrease daytime high temperatures. Decided to blend the NBM75th with the GFS to get record temperatures, but not in the realm of completely obliterating the records. The fewer number of daytime hours will likely prevent the area from completely obliterating the records, but with some downslope expected along and east of the Laramie Range, this can also not be completely ruled out. Still kept temperatures in the 70s and 80s for most days, leading to record temperatures for much of the area. Wednesday will be the coolest day until Sunday with highs currently forecast to be in the upper-60s west of the Laramie Range and low- to mid-70s east, with a couple sites around 80F.

Unfortunately, this ridge will be quite dry with precipitation and moisture no where to be found. As a result, record warmth combined with seasonal dryness will lead to afternoon minimum humidities dropping into the 10 to 15% range every afternoon through Saturday, with overnight humidity recoveries expected to only be around 30 to 45%. With seasonal breeziness expected, this will be the perfect set up for critical fire danger every afternoon with limited recovery overnight. The Red Flag Warning will remain in effect through Saturday evening, with very dangerous fire conditions expected. Outdoor burning is not recommended, even in enclosed fire pits, etc.

LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/

Issued at 1219 AM MDT Wed Mar 18 2026

No major changes to the forecast. Please see previous discussion...

The upper-level ridge will dominate the pattern through most of the weekend. NAEFS percentiles for 500mb geopotential heights are currently forecasted to be at climatological maximum. Regional sounding site climatology indicates recorded maximum 500mb heights for this period are near 5,800 meters with ensembles predicting heights greater than 5,820 meters through Friday. All this to say this is an anomalous pattern, with very warm weather expected.

This ridge will be responsible for pushing the 700mb jet northward, which should lessen the winds by Sunday, though Friday and Saturday could still be gusty. Warm and dry air from the desert Southwest will be advected into the Intermountain West. Unseasonably warm conditions are threatening daily record maximum temperatures Thursday through Saturday. The Intermountain basins may reach the 70s, while areas on the plains are progged to reach the 80s, and in some valley spots of the Nebraska Panhandle could make it to 90 Saturday.

This dry and warm air will drive dewpoints into the teens and at the highest elevations into the single digits. Relative humidity remains impressively low during the daytime in the range of 10-15 percent. The poor overnight recoveries will dry out most fuels. The red flag warning that starts Wednesday Morning will continue until 8 PM MDT this Saturday for forecast zones north and west of the Laramie Range. Overnight Saturday may mark a departure from this pattern in the form of a weak cold front passage. A mid-level moisture plume could support some enhanced precipitation chances, especially at higher elevations. Locations along I-25 and west may become saturated enough to allow some showers to reach the surface. Temperatures will drop into the 50s yet remain about 5 degrees average for this time of year. Beyond this brief disturbance, ridging pattern appears likely to rebuild and linger into the middle of next week.

AVIATION /06Z TAFS THROUGH 06Z THURSDAY/

Issued at 1104 PM MDT Tue Mar 17 2026

VFR conditions will dominate across all terminals for the duration of this TAF period. Winds may pose a threat to aviation operations for the southeast Wyoming sites as they remain gusty, 25 to 45 knots tonight into Wednesday afternoon. After 00Z Thursday, winds will diminish to less than 15 knots. For the Nebraska terminals, winds will remain less than 10 knots tonight and pick right back up after 18Z Wednesday with west/northwest gusts 20 to 30 knots. By 03Z Thursday, winds across the Nebraska panhandle will decrease to less than 10 knots.

CYS WATCHES/WARNINGS/ADVISORIES

WY...Red Flag Warning from 10 AM this morning to 8 PM MDT Saturday for WYZ417>419-430>433. High Wind Warning until 6 PM MDT this evening for WYZ110. NE...Red Flag Warning from 10 AM this morning to 8 PM MDT Saturday for NEZ434>437.