textproduct: Western and Central Wyoming

KEY MESSAGES

- Scattered showers and thunderstorms develop between 1 PM and 3 PM Monday with stronger storms possible between 4 PM and 8 PM. The best chances for showers and storms will be across western, central, and northern Wyoming.

- A few strong to severe storms cannot be ruled out with the main concerns being frequent lightning, strong wind gusts around 50 mph, and hail one-half to one inch diameter hail.

- Another round of showers and thunderstorms Tuesday, although coverage will be less widespread. Chances further decrease Wednesday.

- Warm and dry conditions return for the second half of the week with record-breaking heat possible the weekend of July 11-12.

DISCUSSION

Issued at 243 AM MDT Mon Jul 6 2026

Sunday saw some of the warmest temperatures of the season so far across the Cowboy State. Portions of the Bighorn Basin flirted with the century mark, while central WY saw highs in the mid to upper 90s and locations west of the Divide hit the upper 80s to even 90F. These warm temperatures may be a brief hint at what could possibly be on the horizon. However, there is still a whole week of weather to address before that.

The work week will start with a nice break from the heat and possibly some precipitation across the CWA today. A weak cold front has worked its way across northern WY this morning and is likely to remain stationary over the northern portion of the state. The frontal passage has brought some cooler temperatures but more importantly increased dewpoints mainly over northern WY. High temperatures are expected to get into the upper 80s to low 90s east of the Divide and low to mid 80s west of the Divide. A shortwave will gradually start making its way across northern Idaho, portions of Montana, and northwestern Wyoming this afternoon and evening. This will begin to initiate convective development, while also slowly pushing in above normal PWATs to much of the area. A few isolated showers cannot be ruled out during the morning hours mainly over western WY. Convection really kicks off after noon, across western/central WY with showers and storms gradually spreading north through the afternoon and evening. Precipitation chances will be the greatest across western, central, and northern WY. Chances range from 20 to 40% for much of the previously mentioned area with higher chances of 30 to 60% over northern WY. Drier air will likely hinder precipitation chances from Rock Springs to Casper. The Storm Prediction Center has highlighted portions of northern and central WY this afternoon/evening for a marginal risk (1 out of 5) of severe storms. The main hazards being strong gusty winds and possibly hail greater than 1 inch. The greatest instability will likely remain across northern WY where dewpoints may near 50F. CAPE values look to range from 500 to possibly 1,000 J/kg over this area. Lesser CAPE around 500 J/kg will be across much of central and southwestern WY. The nearing shortwave looks to create some favorable 700-500 mb shear with values of 30-40 kts across portion of central and especially northern WY. Favorable steep lapse rates are likely to be in place leading to the potential for a strong to severe storm or two during the mid to late afternoon. PWAT values look to be nearly 100-150% above normal, so some storms especially across northern WY may be capable of producing a period of moderate to heavy rainfall as well. Overall, scattered showers and thunderstorms will be possible during the afternoon and evening mainly across western, central, and northern WY. The main concerns will be frequent lightning, strong gusty winds, small to large hail (~1"), and possibly a few moderate to heavy rain showers. One thing to mention is that dewpoint depressions across Sweetwater and portions of Natrona/Fremont County will likely be around 45-55F. This means if any storms do develop nearby, which does not look likely (10-20%) there could be a few strong gusty outflow winds of 45 mph or more.

Showers and weakening storms may linger after sunset but should gradually dissipate through the late evening Monday into the early morning hours Tuesday. Some CAMs do show another round of light showers move through western WY during the early morning hours Tuesday. Currently, chances sit around 20-40% with lesser chances east of the Divide. Tuesday could see another day of scattered showers and thunderstorms but the caveat being widespread above normal moisture. Some strong to severe storms cannot be ruled out with the main concerns likely being strong gusty winds and hail. Due to above normal PWATs, some minor flooding cannot be ruled out, especially in poor drainage areas. Temperatures Tuesday look to get into the mid to upper 80s east of the Divide and low 80s west of the Divide.

After Tuesday models are trending towards a drier and warmer second half of the work week. Temperatures look to gradually warm back into the low 90s east of the Divide and mid to upper 80s west of the Divide. Some showers and thunderstorms cannot be ruled out Wednesday but at this time chances for moisture look slim.

Long range forecast models have been hinting at this for a little while now and that "thing" is a rather anomalously potent ridge building over the western/central CONUS. While still nearly a week out there is time for things to change but at the moment, there is good consensus among long range forecast models. 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. Temperatures continue to soar for the weekend with probabilistic models showing a 30-70% chance for highs near or above 100F east of the Divide and 40-80% chance for highs around 105F for portions of the Bighorn Basin. Locations west of the Divide do not look to be spared with a 20-50% chance of highs to get into the mid 90s. There is certainly potential to see widespread daily high temperature records broken and the potential for all time high temperature records to be broken too. Overnight temperatures do not look to cool all too much with breezy winds keeping lows above 60 across locations east of the Divide. Overall, there is still time for things to shift and change. However, there is certainly an increasing potential for a record breaking prolonged period of heat. So unlike that one song, the dog days are not over, so you better be sure to check that A/C is working properly!

AVIATION /12Z TAFS THROUGH 12Z TUESDAY/

Issued at 423 AM MDT Mon Jul 6 2026

VFR conditions are expected to prevail across all terminals through much of the TAF period. Winds remain light through much of the morning at 5 to 10 knots. Winds increase by the afternoon with speeds of 10 to 15 knots and gusts of 15 to 20 knots. Showers and thunderstorms are expected to start developing after 18Z Monday. All terminals will have chances for showers and thunderstorms with KRKS being the lone terminal with only vicinity precipitation. Showers and thunderstorms will be capable of producing strong gusty outflow winds of 40 knots or more at times. 22Z Monday to 02Z Tuesday will likely be the best window for thunderstorm activity across nearly all terminals. If any storms move directly over a terminal brief MVFR to IFR conditions may be possible. KJAC, KPNA, and KBPI may see scattered rain showers after 04Z Tuesday with conditions likely to improve and dry out by the end of the period. Some showers and thunderstorms may linger into the early morning hours on Tuesday nearby KCOD. Otherwise, nearly all terminals should dry out by the end of the TAF period with light winds and clearing skies.

RIW WATCHES/WARNINGS/ADVISORIES

None.