textproduct: Western and Central Wyoming

KEY MESSAGES

- The heat returns today with many locations having highs in the 90s. Heat will last into early next week, with the warmest temperatures from Friday through Sunday when some highs around 100 are possible.

- Low humidity and gusty wind will likely bring critical fire weather to the southeastern half of the area this afternoon and evening.

- Fire weather concerns continue into the weekend as well. Concerns may ease early next week with less wind and somewhat higher humidity move in.

- Monsoonal moisture should return next week with an increased chance of showers and thunderstorms, although details with the most active day remains in flux.

DISCUSSION

Issued at 227 AM MDT Thu Aug 6 2026

As a member of Generation X, one of the music genres I listen to one shift is 80s music. And I heard a song tonight that remains me of my main dilemmas over the next few days. And this song is by one of the greatest artists of that era of music, Madonna, And it was her first Top 10 hit back in 1984, the song "Borderline". The juxtaposition the weather and the song is criteria for potential hazards, mainly of the fire weather and heat variety, which could be borderline the next few days. We will handle each hazard individually in the discussion. So we will see if the atmosphere can keep on pushing criteria over the borderline of hazard criteria.

HEAT...The overall reasoning of the forecast remains the same this morning, with ridging over the Desert Southwest gradually building northward into the Great Basin and toward Wyoming. This will raise heights through Saturday, resulting in a more stable atmosphere and basically no chance of convection through that period. It is also raising 700 millibar temperatures, bring some of the over 20 degrees celsius variety starting Friday and continuing into Sunday. This will lead to another period of hot temperatures across the area, with some record highs once again possible. It will be hot today, with widespread 90s in the lower elevations East of the Divide, The really warm temperatures kick in starting Friday. The National Blend of Model Ensembles give a greater than 2 out of 5 chance of over 100 degree temperatures from Worland to Thermopolis as well as locations under 5000 feet in the Wind River Basin and similar elevations around Casper. The heat looks to peak on Saturday, with most locations under 5300 feet having a 1 out of 2 chance of high temperatures over 100. Like the heat last weekend, the most hottest conditions should be in central Wyoming, where the warmest temperatures aloft will be. It may be a bit cooler on Sunday, probably similar to Friday. And even into Monday and Tuesday, it will remain quite hot. A bit cooler than the weekend but still above normal for this time of year. The main reasons for things being a bit cooler than in July are the smoke over the area, which may filter the sun a bit, along with the longer nights and somewhat shorter days allowing more cooling and less time to heat up during the day.

And this leads to the concern for possible Heat Advisories. The time of concern would be Friday into Sunday. It is borderline because dew points and humidity will remain very low. In addition, with the dry air and longer nights, most locations should cool into the 50s at night, providing some relief. So, we will hold off for now. The day shift can take another look today.

FIRE...The reasoning here is the same as yesterday as well. There is nearly an 100 percent chance of critical humidity through the weekend, with some locations having humidity as low as 5 percent. The borderline condition is the wind. Unlike the past two heat waves, we will be closer to the top of the ridge. And this will bring more wind. For today, given the very low humidity and very dry fuels, we hedged toward issuing Red Flag Warnings. The area with the warnings is the area that has at least a 1 out of 2 chance of wind gusts over 25 mph for three hours this afternoon and evening. And it encompasses most of the southeastern portion of the county warning area.

We will still have to take this day to day. With the ridge building northward, it could decrease wind somewhat Friday and Saturday, especially for areas East of the Divide, dropping wind gusts below the borderline of Red Flag Criteria. I did give thought to a multi day Red Flag across southern Wyoming, especially Sweetwater County where wind is expected to remain rather gusty. But with still some uncertainty, we held off for now. Again, the day crew can take a look and see if we need to extend some of the warnings. These borderline conditions continue into the weekend as well. These concerns may finally begin to ease early next week as humidity starts to rise a bit and wind decreases somewhat.

We may see a bit of a pattern shift next week. The ridge will weaken somewhat and retreat to the south and east, allowing some monsoonal moisture to begin to slide up the backside of the ridge. We can't rule out a stray shower even late Saturday, but coverage would be very sparse. The chance does increase somewhat on Sunday, mainly across the west. In addition, much of the moisture looks to be of the mid level variety so any shower or storm would produce more wind than rain. This looks to be the pattern into the middle of next week, with some convection possible each day but with precipitable waters remaining fairly close to normal, not a lot of rain. Some guidance indicates somewhat deeper moisture moving in for next weekend, but this is still 10 days out so uncertainty, needless to say, is very high. So, the concerns of the forecast, to sum it up, are whether or not certain criteria for hazards could be pushed, as was stated earlier, over the Borderline.

AVIATION /06Z TAFS THROUGH 06Z FRIDAY/

Issued at 1011 PM MDT Wed Aug 5 2026

Primarily VFR conditions will prevail through the period under a dry northwest upper flow. However, wildfire smoke may occasionally result in MVFR conditions through the period. Low confidence on this precludes keeping MVFR conditions in the forecast for now. Wind will increase again after 18Z, with gusts to around 20 knots for several terminals. Lighter wind prevails at all terminals after around 02Z Friday.

Please see the Aviation Weather Center and/or CWSU ZDV and ZLC for the latest information on smoke, icing, and turbulence forecasts.

FIRE WEATHER

Issued at 227 AM MDT Thu Aug 6 2026

A combination of humidity falling as low as 5 percent and wind gusting to 30 to 35 mph should bring critical fire weather to much of central and southern Wyoming today. Elsewhere, although wind should remain below critical levels, dry fuels and low humidity will bring elevated to near critical fire conditions this afternoon and evening. Fire weather concerns continue into the weekend, with elevated to critical fire weather possible through at least Sunday, with some variability in most impacted areas each afternoon and evening.

RIW WATCHES/WARNINGS/ADVISORIES

Air Quality Alert until 11 AM MDT this morning for WYZ001>020- 022>030.

Red Flag Warning from noon today to 9 PM MDT this evening for WYZ277>281-283-288-289-300.