textproduct: Cheyenne

KEY MESSAGES

- Critical fire weather conditions and record warmth continue through Wednesday evening.

- A cold front arrives on Thursday with a cool-down in temperatures through the end of the week.

SHORT TERM /THROUGH SATURDAY NIGHT/

Issued at 115 PM MDT Wed Mar 25 2026

Record warmth continues over southeast Wyoming and western Nebraska this Wednesday afternoon. Most observation sites east of the Laramie Range are at or above 80 degrees, with mid to upper 80s reported in Scottsbluff, Sidney, and throughout much of the Nebraska Panhandle. Daily record highs will be shattered by at least 10 degrees at nearly all climate sites today, with temperatures coming within a degree or two of the March monthly record temperatures, many of which were just set this past Saturday. Critical fire weather conditions with RH well below 15% and wind gusts over 25 mph are also common throughout southeast Wyoming and into southwest Nebraska. The current Red Flag Warning highlights continue in all but the high mountain zones through 8-10pm this evening.

Despite the extremely dry weather and record warmth, there remains a slight chance of showers and possibly some thunder late this afternoon and early evening. While upper-level forcing is almost nonexistent, the extremely hot surface temperatures should breach convective temperatures late this afternoon even despite such high T/Td surface spreads. Forecast soundings show a slight increase in mid and upper-level moisture around peak heating and a few scattered high-based convective clouds can already be seen on GOES visible satellite imagery as of 20z. Most CAM guidance does show initiation of a few isolated very- high-based showers around or slightly after 0z in the southeast NE panhandle as well as far southern Wyoming. While confidence is fairly high that showers will form, any precipitation will have to fall through a deeply mixed surface layer. Most, if not all of the shower activity should evaporate before it reaches the ground however an isolated 0.01" of rainfall or so can not be ruled out along the I-80 corridor, especially in southwest Nebraska. CAM guidance also indicates around 100-300 J/kg of CAPE in the mid-levels, perhaps enough instability to generate some thunder. Any isolated cloud to ground lightning could result in fire starts, so we will have to monitor any convection closely.

Attention turns to the next weather event, a cold frontal passage, which will dive south through the high plains on Thursday. The front will reach the northern zones including Douglas and Chadron before sunrise, and will slide southward through BFF, SNY and eventually CYS by early afternoon. This front will bring a sharp drop in temperatures and a dramatic increase in surface RH values. Low stratus behind the front will develop through the evening as east to northeasterly upslope flow sets in. Another reinforcing front will move through on Thursday night into Friday morning, which will cool things down even more and enhance upslope flow. Isolated stratiform showers and drizzle will be possible in the southern Laramie Range and perhaps along the Cheyenne Ridge on Thursday night through Friday morning, however HREF ensemble QPF does not amount to more than a few hundredths of an inch.

High confidence exists for much cooler weather from Thursday night through Saturday morning. In fact, high temperatures on Friday will end up around or perhaps even a degree or two below average behind the frontal passage. This will feel like quite a shock to the system after such warm weather over the past several weeks (and months), however much of the area should only be in the low 50s for highs in late March! Temperatures will quickly rebound on Saturday as ridging returns aloft and the shallow post-frontal surface layer is mixed out. With a dry and warm airmass in place, there is high confidence in near-record warmth this weekend once again.

LONG TERM /SUNDAY THROUGH WEDNESDAY/

Issued at 115 PM MDT Wed Mar 25 2026

- Sunday will be dry and mild. Increasing chances for showers will occur for Monday through Wednesday as a weather disturbance and cold front approach the forecast area.

Saturday night-Sunday...The warming and dry trend continues as the flow aloft backs to westerly, inducing surface lee trough development across our forecast area. 700 mb temperatures near 9 Celsius will produce maximum temperatures in the 70s to lower 80s.

Monday...Continued mild as the flow aloft remains from the west. With some low and mid level moisture, we may see isolated to widely scattered late day showers.

Tuesday...As a shortwave trough aloft and its associated cold front pass by the forecast area, high temperatures will decrease into the 60s to mid 70s. Looks like enough low and mid level moisture to combine with frontal lifting to produce scattered showers, most numerous near the Colorado state line.

Wednesday...Even cooler in the wake of the Canadian origin cold front. With broad troughiness across the forecast area and increasing low and mid level moisture, we will see scattered to numerous showers develop.

AVIATION /06Z TAFS THROUGH 06Z FRIDAY/

Issued at 1115 PM MDT Wed Mar 25 2026

Isolated to scattered showers are ongoing across much of southeast Wyoming and western Nebraska. These showers are expected to remain weak, but a few may produce a few flashes of lightning and claps of thunder. Showers slowly dissipate through the overnight hours. A cold front will sweep through the area early this morning, leading to wind shifts and lowering ceilings. Precipitation with the frontal passage is expected to be fairly minimal at the terminals. Gusty winds are expected as the front moves through and after the front passes for a few hours.

CYS WATCHES/WARNINGS/ADVISORIES

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