318
FXUS65 KRIW 100726
AFDRIW

Area Forecast Discussion
National Weather Service Riverton WY
126 AM MDT Thu Jul 10 2025

.KEY MESSAGES...

- Widely scattered rain showers will continue over the southern
  half of the forecast area this morning. Isolated showers will
  be possible across areas east of the Divide this afternoon.

- A cold front will move over areas east of the Divide early
  Friday morning, becoming stationary along the Divide. Highs in
  the 70s will be widespread in these areas as a result.

- Dry conditions and a warming trend over the weekend with
  elevated fire weather conditions returning by Sunday.

&&

.DISCUSSION...
Issued at 120 AM MDT Thu Jul 10 2025

Weak showers will continue over the southern half of the CWA this
morning, as a remnant low approaches the area from southern ID. Any
rainfall amounts will be very low, a trace to 0.02", along with very
isolated lightning strikes. Showers will remain isolated over this
area through the rest of the morning after sunrise, as the low
reaches far southern WY. The focus for precipitation will shift east
of the Divide this afternoon, as the low exits over eastern portions
of the state. Wind gusts of 50 to 55 mph will be the main threat,
along with some lightning. Instability will be limited, as CAPE
values will range between 200-500 J/kg. Temperatures will be about
10 degrees cooler across the CWA as a result of the passage of this
remnant low. Fire weather conditions will remain elevated as well,
with critical RH values returning to portions of the Wind River and
Bighorn Basins and Sweetwater County.

A cold front will reach northern WY sometime between 06Z and 12Z
Friday, quickly progressing southward and reaching the Divide by
15Z. Any precipitation looks to be confined to northern portions
through much of the day Friday, but could progress into the Wind
River Basin in the afternoon. Any thunderstorms look to occur along
the Divide, due to the front. Highs in the 70s east of the Divide
remains in the forecast, while areas west of the Divide stay in the
low to middle 80s. Locations in northern Johnson County may not
reach 70 degrees, which would be a 30 degree dip from yesterday.

Dry conditions then return for the weekend, with a somewhat
northwest flow pattern aloft. This will lead to seasonal
temperatures on Saturday and highs in the 90s return for areas east
of the Divide on Sunday. Showers and thunderstorms could be possible
Monday and Tuesday, as another trough drops south from British
Columbia and bringing the trough/cold front through Tuesday
night.

&&

.AVIATION /06Z TAFS THROUGH 06Z FRIDAY/...
Issued at 930 PM MDT Wed Jul 9 2025

VFR conditions expected throughout the period at all TAF sites.
Some ongoing rain showers west of the Divide to include
KBPI/KPNA/KRKS through the morning at 13Z with no confidence of
any other station at this time. Otherwise, light winds and
increasing mid level clouds overnight into Thursday morning.
Increasing winds up to 18kts at most locations, highest at KPNA
up to 25kts after 16Z-18Z through peak heating until sunset
after 01Z-02Z with radiational cooling. Improving skies towards
the end of the period for Thursday night into Friday with
scattered to broken high clouds. No other significant weather
elements at this time with the strong winds at KLND no longer
expected to start the period this evening.

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 120 AM MDT Thu Jul 10 2025

Elevated fire weather conditions will return for one more day
today, with critical RH values occurring along eastern portions
of the Bighorn Basin, the Wind River Basin and Sweetwater
County. Winds will not be a contributing factor, however gusty
outflows could occur (20% chance) from showers over the
Absaroka, Bighorn and Wind River Mountains this afternoon.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$

DISCUSSION...LaVoie
AVIATION...Lowe
FIRE WEATHER...Dziewaltowski