textproduct: Western and Central Wyoming

KEY MESSAGES

- Another day of seasonable temperatures with scattered showers and thunderstorms by the afternoon and evening.

- A few strong to severe storms cannot be ruled out, with the main concerns being frequent lightning, strong wind gusts around 50 mph, and pea-to dime-sized hail.

- Wednesday may see another round of afternoon/evening showers and thunderstorms before things warm and dry out for the end of the work week.

- The upcoming weekend has the potential to be record-breaking with many locations likely to see temperatures near or exceed the century mark!

DISCUSSION

Issued at 328 AM MDT Tue Jul 7 2026

A few showers and thunderstorms continue to linger across the state early this morning. As of writing this around 0100 MDT, a couple flashes of lightning have been detected over portions of western WY. However, convective activity is gradually waning with clusters of lightning continuing to decrease. Precipitation chances will remain mostly across western and northern WY through the predawn hours. Showers and storms will continue to trek east through the morning with the bulk dissipating by sunrise.

A shortwave will be the main instigator for the "active" weather today and Wednesday. The shortwave currently is making its way across Montana while ushering in above normal moisture to the region. This can be seen with PWATs being nearly 100-150% above normal across much of the area. Dewpoints also reflect this with portions of the Bighorn Basin and Johnson County likely to see values in the 50s this afternoon. As for temperatures, they will be similar to Monday with highs in the upper 80s to low 90s east of the Divide and low to mid 80s west of the Divide. Scattered showers and thunderstorms will once again be possible later this afternoon and evening. Coverage today will shift farther south with northwestern WY likely having lesser chances of seeing a shower or storm compared to elsewhere. Precipitation chances across the forecast area aside from northwestern WY look to range from 20-40% with the best chances being over central and portions of southern WY.

The other aspect regarding the convection possible this afternoon and evening, will be the potential for a few strong to severe storms developing. The Storm Prediction Center has highlighted much of the state with a marginal risk (1 out of 5). The only exception to this is portions of northwestern and western WY, specifically much of YNP and the Tetons/Jackson Hole where the marginal risk has been excluded. There is a very small sliver of slight risk (2 out of 5) for a portion of Johnson County mainly due to large hail threat. The setup is a wide swath of above normal moisture across the area. Morning cloud cover is expected to gradually clear by the early afternoon with daytime heating helping produce CAPE values around 500 J/kg over much of the state. Some CAMs are highlighting portions of Johnson County and central WY with swaths of CAPE nearing 1000 J/kg. So if this were to occur, there could be more juice for any storms that develop. Steep low to mid level lapse rates are forecast over much of the state as well. The other factor will be favorable dynamics as a result of the nearby short wave. Low to mid level wind shear values currently look to range from 25 to 35 knots. Overall, the main threat today will be strong gusty winds with CAMs highlighting favorable Downdraft CAPE values. Storms could produce strong gusty outflow winds of 50 mph or more at times. There does remain a threat for hail with the most favorable locations being central and northern WY, specifically Johnson County. Otherwise, frequent lightning and brief moderate rainfall may be possible with any storms. Showers and thunderstorms may linger into the late evening hours Tuesday and possibly into the early morning hours Wednesday.

Wednesday has trended towards another day with possible afternoon showers and thunderstorms. This once again is the result of lingering moisture and the exiting shortwave. Currently, much of the state looks to have similar chances for precipitation as Tuesday. However, chances for strong to severe storms looks to diminish and shift farther east. The SPC currently has far eastern portions of Johnson and Natrona Counties in a marginal risk with the main concerns being strong gusty winds and hail. Aside from these locations, the remainder of the state will see similar hazards as the previous days with frequent lightning, gusty winds, and small hail possible.

No, there does not seem to have been a technical glitch in the long term forecast models, it really is looking to be that hot this weekend. Some long term models have done a good job of indicating this heat as early as last week. Barring some miraculous shift in the weather pattern, we are likely to see a period of dangerously hot, record breaking temperatures this weekend. This heat will be the result of an anomalously potent high pressure ridge that builds across the western/central CONUS. Temperatures start to turn up Friday with current highs getting into the mid to upper 90s east of the Divide and upper 80s to low 90s west of the Divide. The warmest temperatures look to arrive for the weekend. Guidance is showing western valleys such as Star Valley and Jackson Hole possibly seeing highs around 95F Saturday. Locations east of the Divide to no surprise are warmer, with central basins seeing highs nearing the century mark. Northern locations, such as portions of the Bighorn Basin may see highs nearing 105F. Sunday looks even warmer with locations west of the Divide seeing 20-40% of highs nearing 100F. East of the Divide central basins have 20-50% for highs around 105F. Portions of the Bighorn Basin may see highs near 110F with chances sitting around 10-30%. These percentages are to show the potential range for high temperatures. So if there is a 20-50% for highs near 105F, its likely the highs will at least be greater than 100F. There is increasing likelihood that numerous daily high temperature records and even all-time high temperature records may be met or broken. Climate data at KLND goes back to 1891 and the current all time high temperature is 102F set back in 1935 on July 27th. Currently, the NBM has a forecast high of 104F for Sunday, so that should give an idea of how historic this period of heat may be. Yes, this degree of heat can be dangerous for those who are at risk or do not use caution. So be sure to stay up to date on the forecast and be prepared, especially if planning outdoor activities!

AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/

Issued at 438 AM MDT Tue Jul 7 2026

A few isolated showers and thunderstorms linger across the area this morning but far enough away from all terminals to keep conditions VFR. VFR conditions are expected to prevail across all terminals through much of the TAF period. Skies will gradually clear through the morning hours before clouds return by the afternoon with developing convection. Winds remain light at around 5 to 10 knots through the morning. A breeze is expected for most terminals shortly after 18Z Tuesday with winds of 10 to 15 knots and gusts of 20 to 25 knots at times. Showers and thunderstorms are expected to begin developing around 19Z with coverage increasing by 21Z. All terminals except KJAC have PROB30 groups for thunderstorms which may briefly create MVFR to possibly IFR conditions its overhead. Winds will be the other concern with storms capable of producing strong gusty outflows in excess of 40 knots. The majority of showers and thunderstorms should gradually dissipate after 00-01Z Wednesday. A few showers and storms may linger after with VCSH possible at KRKS to end the TAF period.

RIW WATCHES/WARNINGS/ADVISORIES

None.