textproduct: Cheyenne

KEY MESSAGES

- There is a Slight Risk (2 of 5) of strong to severe thunderstorms Friday afternoon. Isolated large hail and strong gusty winds are possible east of Interstate 25.

- Warming temperatures, falling humidity, and increasing winds will increase fire weather concerns this weekend into early next week.

SHORT TERM /THROUGH SUNDAY NIGHT/

Issued at 118 PM MDT Fri Jun 26 2026

Development is beginning this afternoon generally along the front range and just east where a stationary boundary is located. We should see instability rise once again through the afternoon hours, with some light shear currently present but should be strengthening into the evening hours with bulk shear around 30-50 knots. With this environment, it appears that widely scattered thunderstorms will be possible in the next couple of hours and continue into the evening, with large hail and strong wind gusts the primary hazards.

Into Saturday we'll see the dryline move eastwards and bring a much drier environment across the CWA. The one exception to this could be our far eastern Nebraska Panhandle counties, which could see some development during the later afternoon and evening hours, but with how dry low levels will be expectation is that this activity should either be ramping up in this area and will be strongest just east of these counties, or may even be dry in nature as better moisture remains just east. In either case, we should be seeing a break from the stronger storm activity, with daytime relative humidity values back down into the teens and breezy winds accompanying. This should bring an elevated fire weather threat to the area, with the strongest risk for our zones west of the Laramie Range as strong wind gusts are expected with the 700mb jet strengthening to around 45-50 knots. Currently we do not anticipate a Red Flag Warning as last reported fuels remain green, however with how strong these winds may be combined with the dry conditions we are still considering breaking the glass for a warning across this area. Will consult with the evening and nighttime shifts, but a decision may not be made until tomorrow morning.

Sunday we'll see a shortwave rounding the base of the larger western US trough moving across the area with the bulk of the best moisture and storm parameters to the north. This will bring a sliver of a marginal risk for stronger storms across our northern zones, but for the most part we'll only have a slight risk of some showers or possible storms in a mostly mediocre environment. Breezy winds expected again from the low-level jet kicking in, but RH values should slightly increase and limit critical fire weather conditions, with an elevated environment expected. Otherwise expect a meager cold front pass across the region through the day, with highs west of the Laramie Range just under or around 80 degrees, with further east highs sit in the 80's to low 90's, but descending as we move into the long term period.

LONG TERM /MONDAY THROUGH THURSDAY/

Issued at 118 PM MDT Fri Jun 26 2026

The persistent troughing that has been glued to the northwest the better part of the weekend will still be with us to start off the long-term. A strong shortwave on the southern end of this trough will swing by Sunday night into Monday morning with a cold front. We will start off Monday on the backside of the front with winds shifting from the northwest and drier continental air advecting in. High temperatures will be slightly cooler than Sunday's, reaching the upper 70s west and 80s east. Skies should stay mostly clear and winds breezy up to 45-50 mph in some portions of the area. Some high wind conditions may show up along the Laramie Range near the Wheatland area. Most will see gust up to 30 mph. Despite the rainfall we have received the last few days, fuels remain dry in the Nebraska and most eastern Wyoming firezones. The anticipated conditions do incite some concerns in elevated wildland fire possibilities that basically stick around the rest of the long-term period.

Tuesday sees much the same as Monday. Winds relax slightly as the shortwave moves off to the northeast and a ridge axis noses in. This will also mark the start of a warming trend through at least Friday, if not longer. Another shortwave associated with the larger troughing will swing by Tuesday. At the surface enough return flow out of the southeast may allow a few storms to develop as the shortwave moves overhead, primarily for the eastern areas. Past Tuesday temperatures continue to increase each day with a slight chance of afternoon thunderstorms. Bulk windshear stays elevated through this period, so I wouldn't discount some risk of severe thunderstorms. Unfortunately after Friday global ensemble models are hinting at a large upper level high pressure system developing and persisting. If this is indeed the reality of the very long term, we could be in for a long period of hot and dry weather.

AVIATION /18Z TAFS THROUGH 18Z SATURDAY/

Issued at 1155 AM MDT Fri Jun 26 2026

Scattered thunderstorms and showers are expected to develop later this afternoon near the Laramie Range and foothills. This activity could bring heavy rains, lightning, and variable gusty winds. Storms are capable of producing gusts above 50 kts. The coverage is not great enough to include in tempo groups, therefore prob30 groups have been added to terminal TAFS. Outside convection gusty south to southwest winds between 20-35 kts can be expected this afternoon with scattered to broken ceilings around 10 kft.

This evening a few scattered showers may linger at terminals in the Nebraska Panhandle along with lowering ceilings. These ceilings do not appear to be low enough to incite MVFR, however KAIA may have ceilings that dip to MVFR for a few hours in the morning. At KBFF low level wind shear is expected to develop during the morning hours.

Tomorrow winds greatly pick up for most of the Wyoming terminals with some gusts to 40 knots out of the southwest possible. Otherwise, mostly clear skies can be expected through 18z.

CYS WATCHES/WARNINGS/ADVISORIES

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