880
FXUS65 KRIW 062352
AFDRIW

Area Forecast Discussion
National Weather Service Riverton WY
552 PM MDT Thu Aug 6 2026

.KEY MESSAGES...

- Warmer than normal temperatures continue into the weekend,
  with many highs in the 90s. Some highs around 100 are
  possible for basins east of the Continental Divide this
  weekend.

- Areas of dense smoke from wildfires across the Pacific
  Northwest will continue to drift over Wyoming, leading to poor
  air quality and reductions in visibility.

- Low humidity and gusty wind bring critical fire weather
  conditions to much of southern and eastern Wyoming this
  evening. Elevated fire weather conditions continue for
  portions of the state into the weekend.

- Monsoonal moisture may (60% chance) return late next week,
  leading to an increase in humidity, and increased chances for
  showers and thunderstorms.

&&

.UPDATE...
Issued at 200 PM MDT Thu Aug 6 2026

No major changes to the forecast for the week ahead, with hot,
dry, and breezy conditions over the next several days. There are
minimal chances for showers or thunderstorms until next week,
with large scale subsidence over the region. Fire weather
conditions remain elevated tomorrow (Friday), but winds
currently look to be just short of causing critical conditions.
Winds increase area-wide Saturday, and if the current forecast
holds, further fire highlights may be needed. Updated winds over
the next 24 hours using the latest high-resolution forecast
guidance to support fire partner operations in the forecast area,
but no other notable tweaks to the going forecast.

&&

.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 /00Z TAFS THROUGH 00Z SATURDAY/...
Issued at 531 PM MDT Thu Aug 6 2026

VFR conditions are expected to prevail through the TAF period. Smoke
from wildfires across the PACNW are still expected to move through
the region during the TAF period. As a result, all terminals are
expected to see some reduced visibilities but still maintain VFR
conditions. However, patches of dense smoke cannot be ruled out from
mixing down to the surface and possibly creating periods of MVFR to
even IFR conditions. At this time uncertainty is high in regards to
this occurring as models are doing a poor job of forecasting these
smoke plumes. Otherwise, winds are expected to remain breezy across
nearly all terminals this evening. These winds decrease shortly
after sunset with light winds prevailing through the overnight into
Friday morning. Winds begin to increase once again near the end of
the TAF period with nearly all terminals seeing breezy conditions
for Friday afternoon. Winds of 10 to 15 knots with occasional gusts
around 20 to 25 knots will be possible at times. Mountain
obscuration will be possible at times during the TAF period
especially as denser plumes of smoke move across the area.

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 Friday for WYZ001>013-
016>018.

Red Flag Warning until 9 PM MDT this evening for WYZ277>281-
283-288-289-300.

&&

$$

UPDATE...VandenBoogart
DISCUSSION...Hattings
AVIATION...Dziewaltowski
FIRE WEATHER...Hattings