textproduct: Cheyenne

KEY MESSAGES

- Today & Tuesday brings another chance for strong to severe thunderstorms in the afternoon and evening. There is a slight risk (level 2 of 5) across the eastern high plains on Monday. Large hail, severe wind, and an isolated tornado possible.

- A warming and slight drying trend appears likely after Wednesday with temperatures climbing into the 80s by later in the week and during next weekend.

SHORT TERM /THROUGH TUESDAY/

Issued at 428 AM MDT Mon Jun 1 2026

Some showers have moved their way northward from Colorado, however it doesn't appear that any rain is making it to the ground looking at the traffic cams and observations. Today, showers and thunderstorms look to return to the Intermountain West and High Plains. A shortwave will eject off the parent low sitting over the Montana/Saskatchewan border and push through the region. Depending on the timing, this afternoon and evening is a good chance for strong to severe thunderstorms across far southeast Wyoming and most of the western Nebraska Panhandle. Current Hi-res models have reached some consensus and all begin to fire storms around 20/21z for Southeast Wyoming and 23/00z for those storms to reach the Nebraska Panhandle. However, the best moisture return doesn't look to occur til around 00z and may limit the severity of the storms before then. All other parameters look good with 0-6km shear around 40-50 knots. Although some models like the NEST and RRFS show pockets of 60-70 knots of shear after 2z which if that does occur may also limit storm severity as well due to the shear shredding or blowing over the storms. SPC expanded their severe Wind, Hail, and Tor outlooks more to the north to encompass more of the southern half of the Panhandle and is now from Alliance to the CO border.

Tuesday, Models show a subtle shortwave lifting northeast across the area through the day with ample low level moisture and dewpoints in the upper 40s to mid 50s possible. Models depict deep shear and SBCAPE as high as 2000 j/kg for another conducive environment for severe thunderstorms. Relatively low LCL's and with some low level spin (SRH) along and east of the I-25 corridor may indicate a repeat of today's severe risks to which all hazards may be possible but large hail may be most likely. SPC still encompasses majority of our forecast area along and east of the I-25 corridor but the slight risk does end right at our doorstep of the Nebraska/South Dakota border.

LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/

Issued at 150 PM MDT Sun May 31 2026

We remain under SW flow aloft upstream of a high amplitude positively-tilted ridge centered over Ontario and the Great Lakes region, resulting in mostly dry and above-average temperatures heading into the second half of the week. Thanks to trajectories stemming from the Gulf of Mexico, PWAT over SE Wyoming and W Nebraska will be in the 80th-90th percentile relative to climatology. This will allow for daily chances of showers and thunderstorms despite the absence of any large-scale forcing for ascent. Despite anomalously high PWAT, long range ensemble forecast soundings continue to show large dewpoint depressions at the surface and inverted-V profiles, so any showers or storms will likely produce far more wind than any beneficial moisture. The threat for any severe weather looks to remain low towards the end of the week as deep-layer shear is weak due to the lack of mid and upper level flow. Going into the weekend, high temperatures are expected to push 80 degrees west of the I-25 corridor, with even a few 90s for our Nebraska counties as we remain under longwave ridging through the end of the long term period.

AVIATION /06Z TAFS THROUGH 06Z TUESDAY/

Issued at 1118 PM MDT Sun May 31 2026

Mostly quiet conditions expected overnight as a few showers slowly drift across portions of the Nebraska Panhandle. These showers may briefly produce gusty and erratic winds. KBFF has the best chance to see the showers over the next 1 to 3 hours. Isolated thunderstorms may develop early this morning across the Nebraska Panhandle, but confidence is low. KBFF, KSNY, and KAIA have the best chance of seeing isolated thunderstorms. More widespread thunderstorms are expected in the afternoon and evening hours. All hazards are possible with these storms: hail to 2 inches, damaging winds, and an isolated tornado or two.

CYS WATCHES/WARNINGS/ADVISORIES

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