276
FXUS65 KRIW 031103
AFDRIW

Area Forecast Discussion
National Weather Service Riverton WY
503 AM MDT Wed Jun 3 2026

.KEY MESSAGES...

- Mostly sunny skies today with highs in the 70s east of the
  divide and 80s to the east.

- A few showers and thunderstorms move across far northern
  Wyoming Thursday afternoon, with a low chance of stronger
  storms for northern Johnson County. The main threats would be
  gusty winds and hail.

- Warm conditions continue through the upcoming weekend. with
  highs in the 70s and 80s. Saturday will be warmer, with highs
  east of the Divide reaching the 90s.

&&

.DISCUSSION...
Issued at 212 AM MDT Wed Jun 3 2026

The warm year we`ve had so far will continue today, as ridging
returns briefly between weather systems. Skies today will be
mostly sunny, with only fair weather CU along higher elevations
during the afternoon. Highs will again range from the mid 70s
west of the Divide, to the low to mid 80s east of the Divide.

Late Wednesday night, the next shortwave sweeps across the
Northern Rockies. The trough axis will be stretched across
central WY around noon, which will put most of the best lift
already into eastern WY, similar to today. With temperatures
still reaching the 80s east of the Divide tomorrow, the trough
will build more daytime CU, with tiny showers bubbling in the
instability. But with the trough already moving east early
afternoon, the threat for any stronger thunderstorms remains
limited to northern Johnson County, which could see a brief
threat for gusty winds and hail.

The passing trough will also bring a tighter gradient across the
state, so gusty winds will also ramp up, with frequent gusts
above 30 mph expected. This along with humidity levels of 10 to
15 percent in the afternoon will lead to an elevated to near
critical fire weather concern for most lower elevations
Thursday.

After the Thursday system sweeps through, the pattern changes as
a large-scale trough drops down into the PacNW. This will build
ridging across the Plains, with generally southwest flow across
Wyoming. The ridge placement will be favorable for building
temperatures aloft, especially on Saturday. H7 temps of 16 to 18
degrees C will translate to sfc temps in the 90s for the lower
elevations east of the Divide and mid to upper 80s for southern
WY. Southwest flow will be stronger as well, with current
forecast gusts of 30 to 40 mph across a wide swath of the state.
This southwest flow will also be very dry, with humidity levels
plunging to 5 to 10 percent in the afternoon. This points to a
near-critical fire weather day, especially those areas that
haven`t seen considerable rainfall so far this spring.

&&

.AVIATION /12Z TAFS THROUGH 12Z THURSDAY/...
Issued at 501 AM MDT Wed Jun 3 2026

Low cloud deck has shifted in from the northeast into KCPR and
KBYG this morning, but once daytime heating picks up, this layer
should thin quickly. After this, all sites will be VFR through
the next 24 hours. Winds will start to increase this afternoon,
with many locations gusting 15 to 25 knots.

&&

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

&&

$$

DISCUSSION...Straub
AVIATION...Straub