textproduct: Cheyenne

KEY MESSAGES

- Remaining hot on Monday as the upper level ridge axis shifts east into the plains, expect highs to top out in the upper 80s to upper 90s. A few locations may reach the century mark across western Nebraska.

- Conditional thunderstorm chances return Monday in response to increasing moisture.

- Strong to Marginally Severe thunderstorms possible Tuesday through Thursday.

- A ridge builds late in the long term, drying us out and perhaps breaking heat records.

SHORT TERM /THROUGH TUESDAY NIGHT/

Issued at 225 AM MDT Mon Jul 6 2026

Models continue to be in good agreement early this week with very warm/hot conditions remaining over the area for at least another day or two. Breezy early this morning as the low level jet remains over the high plains, with gusts around 40 MPH reported at Chadron, and gusts of 20 to 25 MPH elsewhere across western Nebraska and even far eastern Wyoming. This jet is important because low level moisture advection has brought dewpoints into the 50s across the eastern plains, and mid 40s into Albany county. Although daytime mixing will bring these surface dewpoints down a bit, boundary layer moisture should be sufficient to start seeing an uptick of thunderstorm activity today and continuing for most of the week.

The upper level ridge axis today won't be quite as strong as Sunday as the ridge axis shifts eastward and weakens a bit once a subtle shortwave clips the northern zones late Monday afternoon. Some midlevel cooler air will enter the area which should be just enough to initiate some scattered rain showers and isolated thunder along and east of the Laramie Range. Kept POP around 15 to 30 percent through late Monday evening, highest where a line of multicell thunderstorms attempts to develop just ahead of the shortwave disturbance. This line will struggle to grow upscale due to limited shear, but we can't totally rule it out either. Laramie Valley may get some of this activity early in the afternoon, but boundary layer moisture will be limited. Thunderstorms look sub-severe at this time with only about 15 to 20 knots of shear and MLCAPE between 400 to 800 j/kg, highest over the southern Nebraska Panhandle. Gusty outflow/microburst winds appear to be the main threat from any thunderstorm activity this afternoon. Otherwise, High temperatures will be similar to Sunday with highs in the upper 80s to upper 90s. May see a few locations reach the century mark across western Nebraska.

For Tuesday, slightly better convective parameters and shear compared to Monday with 0-6km shear nudging towards 25 to 30 knots by the end of the day. Models show a better defined shortwave lifting northeast out of Utah and into eastern Wyoming by late Tuesday afternoon. With moisture advection continuing over the area, NAEFS shows east central Wyoming and most of the Nebraska Panhandle above the 90th percentile for PWAT and dewpoints near 60 degrees. High res CAMs show a noticeable uptick in thunderstorm coverage with some organized cells showing up east of I-25 during the afternoon. Expect some strong to marginally severe thunderstorms Tuesday afternoon and evening with isolated large hail and strong gusty winds. Models not in good agreement with boundary layer moisture above the surface and CAPE with the GFS as low as 500 to 1000 j/kg of MLCAPE east of I-25, but the NAM as high as 2500 j/kg. Will keep severe wording out of the forecast for now due to this discrepancy. A slightly cooling trend is expected to begin on Tuesday with high temperatures still very warm in the mid 80s to mid 90s.

LONG TERM /WEDNESDAY THROUGH SUNDAY/

Issued at 131 PM MDT Sun Jul 5 2026

The long term features some storm chances to start off the period and a slight cooling trend as monsoonal moisture advects in from the west. By next weekend the ridge over the four corners region may strengthen pushing temperatures towards all time record highs.

Wednesday and Thursday feature much the same weather as Tuesday. The moisture does potentially increase some allowing more widespread precipitation chances. Wind shear does increase, so we may see a few more organized storms with hail and wind threats. The increased cloud coverage and storms may keep most of the region under 90 degrees. This will be possibly the last good chance we get for rainfall for some time as the ridge builds over the area. Ensemble members have this ridge reaching some 8 to 10 decameters above climatological average. Deterministic models have up to 15 to 18 decameters above average. Such a strong ridge will create significant subsidence in the lower levels, warming and drying us out. Relative humidity values in the single digits and temperatures over 100 are certainly possible over the weekend east of I-25. Critical fire weather would arise from these conditions and receptive fuels. While a ways out, there is a possibility that all time record highs are broken Sunday or Monday at a few locations. If the ridge center shifts to our east we also have a downsloping effect that would nudge temperatures up a few degrees. Hopefully the ridge ends up not as intense as models are suggesting.

AVIATION /18Z TAFS THROUGH 18Z TUESDAY/

Issued at 1143 AM MDT Mon Jul 6 2026

Most terminals will experience VFR conditions through this afternoon. A complex of thunderstorms and showers are expected to develop near the Laramie Ranges and along the boundary of this mornings showers and thunderstorms just north of the Nebraska Panhandle. These storms could impact terminals through the early evening with the main hazards being reduced visibilities from heavy rain and blowing dust along with strong downburst winds, possibly to 40-45 knots, and lightning. Therefore, PROB30 groups are maintained for airports with the greatest chances of storms. Winds will be variable at times outside of storm cores and could have long distance influences.

Tomorrow morning continues VFR conditions. Winds in the Nebraska Panhandle pick up from a low level jet with gusts to 30 knots possible out of the south. Before the jet reaches the surface, there is a slight risk of low level wind shear over KBFF from 08-11z.

CYS WATCHES/WARNINGS/ADVISORIES

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