039
FXUS65 KRIW 110348
AFDRIW

Area Forecast Discussion
National Weather Service Riverton WY
948 PM MDT Thu Jul 10 2025

.KEY MESSAGES...

- Warm but more seasonable temperatures across the Cowboy State today

- Isolated showers and thunderstorms will be possible this
  afternoon and evening mainly over central and northern WY.

- Cooler temperatures arrive for Friday as a cold front moves through
  the state. Highs may be 10 to 15 degrees cooler than
  Thursday.

- The frontal passage will bring chances for showers and thunderstorms
  throughout the day Friday.

&&

.UPDATE...
Issued at 1249 PM MDT Thu Jul 10 2025

Showers and thunderstorms that developed over portions of western
and southern WY this morning have dissipated. Satellite imagery
shows clearing skies with some isolated convection starting to
develop over central and southern WY. Coverage will be limited
mostly to east of the Divide and gradually spread to the east
throughout the afternoon and evening. The main concern with any
showers and thunderstorms will be strong gusty outflows of 50
mph or more. The atmosphere remains fairly dry which may lead to
virga showers and an isolated dry thunderstorm or two.
Temperatures are still on the warm side with highs in the upper
80s to low 90s east of the Divide and mid 80s west of the
Divide. A cold front is nearing the state and is expected to
start moving into the area by the late evening tonight.

The frontal passage is expected to bring cooler temperatures and
chances for precipitation. Highs are forecast to be nearly 10 to 15
degrees cooler than Thursday. Temperatures east of the Divide will
range in the mid to upper 70s with values in the upper 70s to low
80s west of the Divide. Shower and thunderstorms will be possible on
Friday as the front passes with the best chances remaining across
central and northern WY. Elevated PWAT values do look to possibly
move into the region for Friday with above normal amounts
mainly east of the Divide. This may create some brief heavy
downpours but these are expected to remain fairly isolated.

The weekend sees warmer and drier conditions return to the area with
highs reaching the upper 80s to low 90s. The next chance for
precipitation does not look to arrive until the start of next week
as a trough moves across the region. Another front moves through the
area around Tuesday night bringing in a brief period of cooler
temperatures. The remainder of the week looks to have increased
chances for precipitation as multiple disturbances move through the
region.

&&

.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 SATURDAY/...
Issued at 945 PM MDT Thu Jul 10 2025

VFR conditions expected to persist through the period with the
cold front continuing to slide through the CWA overnight.
Increasing northeast winds behind it at CPR/COD/WRL to start the
period through 12-13Z. Confidence has diminished even more for
any rain shower activity around COD in the morning and only
down to carrying VCSH at this point in time (<15%). Otherwise,
in wake the front and post frontal trough, expect another round
of isolated thunderstorm activity east of the Divide. Confidence
has increased (30-40%) for a more confined timeframe between
19-00Z for all but CPR, that will occur later between 00-02Z.
Minor restrictions to visibility and stronger winds with these
weaker, more cold-pooled based storms. Improving conditions
with weaker winds and scattered upper level clouds towards
sunset and overnight Friday into Saturday morning.

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

&&

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

&&

$$

UPDATE...Dziewaltowski
DISCUSSION...LaVoie
AVIATION...Lowe