textproduct: Cheyenne

KEY MESSAGES

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

- Marginal Risk of strong to severe thunderstorms this weekend for the western Nebraska Panhandle. Hail and strong gusty winds are possible.

SHORT TERM /THROUGH SUNDAY NIGHT/

Issued at 245 AM MDT Sat Jun 27 2026

Showers and thunderstorm continue early this morning over the northern Nebraska Panhandle as the low level jet increases over the Great Plains. Low to midlevel meso-analysis showing MUCAPE of 1500 j/kg in and around Chadron Nebraska. Was a bit concerned about the South Fork Burn scar west of Chadron and Crawford as a strong thunderstorm moved near the area between 1 to 2 AM. Radar estimates in the core of the cell were nearing 1 inch of rain/hour. Thankfully, the cell redeveloped further south and east...sparing most of the area. Will continue to monitor trends and river levels this morning, but not anticipating any flash flood products at this time as the westward extent of the line enters north central Sioux county at this hour.

Although drier air will continue moving into the region today, it is forecast to advect into the area much slower than previously thought a few days ago. Currently, dewpoints are in the upper 50s and low 60s as far west as Cheyenne, Wheatland, and Douglas under southeast upslope winds. Even some low clouds and patchy fog have been observed early this morning. Fire weather concerns are expected to be delayed a day or two over most of eastern Wyoming and western Nebraska with dewpoints remaining in the low to mid 60s across the Panhandle this morning. In addition, flash flooding was more widespread than expected yesterday with 1 to 2 inches of rain observed in many locations...especially in and around Scottsbluff and Bridgeport Nebraska. A dryline is expected to form this afternoon and slowly drift eastward into far eastern Wyoming and western Nebraska. This will likely result in enough convergence and forcing to initiate isolated to widely scattered thunderstorms over western Nebraska (depending on the dryline location). Added 15 to 25 percent POP and Prob thunder east of a Lusk to Kimball line. Dry air is currently over Carbon county and is going to take its time moving into the I-25 corridor, but do expected this to happen sometime around noon. Most model guidance shows dewpoints remaining in the 50s for portions of the Nebraska Panhandle well into the late afternoon hours. Although high res guidance hasn't caught on to the convection initiation, expect storms to develop somewhere near the Nebraska border and move northeast. With enough shear and CAPE, expect a few to become strong to marginally severe with strong gusty winds the primary concern, and hail and heavy rainfall secondary concerns.

Models show the drier airmass moving into western Nebraska for Sunday as a Pacific upper level trough tracks east of the Great Basin region and into Wyoming and Montana. In fact, some late season snow is expected over Montana from this system. For southeast Wyoming, mainly dry with warm temperatures ahead of the cold front. Highs in the 80s to low 90s are expected with 70s west of I-25 as the cold front begins to push into central Wyoming. Once this front begins to move east later on Sunday, a surface low is expected to form across the plains and rapidly move northeast. Additional moisture advection is expected with return flow off the Great Plains as winds shift into the south or southeast. Models are indicating another round of thunderstorms later Sunday and possibly Sunday night as a rare (for this time of the year) 100kt jet max lifts northeast into the eastern plains. Plenty of upper level diffluence is noted with this feature along with surface convergence near the frontal boundary. Increased POP Sunday evening and Sunday night along and east of the I-25 corridor. Some strong to marginally severe thunderstorms are possible due to pretty good forcing for late June.

LONG TERM /MONDAY THROUGH FRIDAY/

Issued at 121 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 /06Z TAFS THROUGH 06Z SUNDAY/

Issued at 1145 PM MDT Fri Jun 26 2026

Thunderstorms are coming to an end, so expect a return to VFR conditions across all terminals through the remainder of the overnight hours. Winds will ease across most sites, except KCDR and KAIA where gusts will continue to top out to around 30 knots. Otherwise, winds will ramp back up for the remainder sites, with gusts 30 to 45 knots, top end for KLAR and KRWL, by 16Z Saturday. Another round of thunderstorms Saturday afternoon are possible for KBFF, KCDR, and KAIA. However, confidence is low so a PROB30 group was added to account for this.

CYS WATCHES/WARNINGS/ADVISORIES

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