textproduct: Cheyenne

KEY MESSAGES

- The potential for a few afternoon and evening strong to severe thunderstorms will continue through the remainder of the work week.

- Temperatures will slowly warm to well above seasonal averages by the weekend as thunderstorm chances become more isolated.

SHORT TERM /THROUGH THURSDAY NIGHT/

Issued at 117 AM MDT Wed Jun 3 2026

Stronger thunderstorms have finally departed the region just to the northeast across the Nebraska/South Dakota border area. Some low clouds or fog may redevelop though through this morning, with the best potential across the northern Nebraska Panhandle and perhaps into Niobrara County. Otherwise we should remain clear and relatively quiet through the rest of the morning hours into the day, when we'll be looking at our next chance of thunderstorms and some strong to possibly severe activity. Aloft, we'll see a small embedded shortwave moving over the region within the stronger flow from an upper level low just over the border in Canada. At the surface, we'll be looking at a weaker environment than the previous several days, with dewpoints struggling a bit more particularly into Wyoming in the 40's with some 50's for the Nebraska Panhandle, while instability remains relatively meager in the 500-800 J/kg range, though some 1000-1300 values are possible in the Nebraska Panhandle. Meanwhile SRH will also be limited with values barely into the 100 m2/s2 range, though once again we may see some 200-300 values int he Panhandle. Convection should get going just after noon in southeastern Wyoming and will continue into the Panhandle through the beginning of the evening, but by the time the sun goes down the bulk if not all activity should be eastward and out of the region. Any storms that do form will have the potential for the bare minimum of severe potential, with gusty winds or some hail not out of the question.

Moving into Thursday the upper low over Canada will progress eastwards and clear the area, but another shortwave embedded in the overall flow should pass across and bring another risk of thunderstorms during the afternoon and evening once again. The bulk of the strongest activity on Thursday should actually be further north across Converse and Niobrara Counties and into the northern Nebraska Panhandle where a surface low and frontal boundary will be located. Latest high resolution guidance indicates the environment in this region will be primed for much stronger convection compared to Wednesday, with around 1000-2000 J/kg of MUCAPE, though isolated values in excess of 2500 in Dawes County can't be ruled out. This alongside SRH values 200-400 m2/s2 will promote stronger to severe storms with strong winds, large hail, and perhaps even an isolated tornado or two. Convection does begin to wane though into the early evening timeframe and as the front and low pass eastwards, but lingering activity from remnant boundaries can't be ruled out with favorable convective parameters still lingering. By the overnight hours though convection should be exiting the area. And for already saturated areas such as Dawes County, storms will be fairly quick moving and so the potential for heavier precipitation should be lower, leading to a lessened flood risk.

Outside of our thunderstorm potential, we'll be looking at a pair of fairly warm days in the short term, with highs in the upper 70's to upper 80's today, jumping to the 80's to low 90's on Thursday. Some breezier conditions may also be possible on Thursday across Carbon and Albany Counties from an enhanced pressure gradient, but we're definitely not back in high wind territory at this time.

LONG TERM /FRIDAY THROUGH TUESDAY/

Issued at 1242 PM MDT Tue Jun 2 2026

Storm chances will drop back somewhat for Friday as drier air pushes eastward to encompass most of the forecast area. A deep Pacific trough pushing into the northwest CONUS will amplify the downstream ridge over the Rockies and Plains, pushing temperatures upward into the weekend. Most areas will reach the 80s on Friday, with fairly widespread 90s possible Saturday as the ridge axis shifts overhead. 700-mb temperatures peaking around +12 to +16C will be around the climatological 90th percentile. Sunday's highs may drop slightly for our western zones, but should be fairly similar to Saturday over the High Plains, with widespread mid 80s to mid 90s. Current forecast remain comfortably below daily record highs, but it will certainly be a warm to hot few days.

While precipitation on Friday looks very isolated, moisture will begin to slowly tick upwards again Saturday onward. Moisture will improve aloft first, increasing on Saturday. This could lead to a few isolated high-based showers and possibly a dry microburst hazard, but this is fairly low confidence several days out. Low- level moisture looks to recover Sunday into early next week, which will then allow for higher chances for appreciable precipitation, but also strong to severe thunderstorms. An early look from the ECMWF ensemble suggests fairly potent instability and thus more prevalent thunderstorm chances on Monday and Tuesday.

AVIATION /12Z TAFS THROUGH 12Z THURSDAY/

Issued at 514 AM MDT Wed Jun 3 2026

Mostly VFR conditions expected, with two exceptions. The first will be low clouds near KCDR and KAIA, with the most likely location to see low CIGs being KCDR. That being said, with enough uncertainty, have left lowered conditions out and placed SCT005 in for now, but this may need an amendment through the morning hours. Secondly will be thunderstorms which could bring lowered VIS, primarily impacting KCYS and the Nebraska terminals. Storms could also be strong and cause variable gusty winds. Otherwise look for primary CIGs to be either medium to high based or clear outside of thunderstorms, with prevailing winds generally 10 knots or less outside of KLAR and KRWL where some breezy conditions are possible today.

CYS WATCHES/WARNINGS/ADVISORIES

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