072
FXUS65 KRIW 010740
AFDRIW

Area Forecast Discussion
National Weather Service Riverton WY
140 AM MDT Mon Jul 1 2024

.KEY MESSAGES...

- A cold front today brings cooler temperatures and rain
  chances, mainly across the northern half of Wyoming.

- Rain chances for northern Wyoming through midweek, with cool temperatures.

- Warm and dry conditions looking more likely into next weekend.

&&

.DISCUSSION...
Issued at 139 AM MDT Mon Jul 1 2024

A cold front moves through the area today. As a result, it will be
noticeably cooler, especially compared to the highs yesterday that
were in the 90s for many locations, with a few 100s noted. Highs
today peak in the 70s for most, with some low 80s in central
Wyoming. This front also brings the chance of rain. As it sweeps
through the area this morning, a line of showers and storms
accompanies it. The most likely places to get rain are across
northern Wyoming. As the line tracks southeastward, lesser chances
occur over the basins, such as the Green River and Wind River
Basins; chances for these places are more in the 20% to 30% range.
The best chances continue across the northern part of the state
through the day as broad trough influences the area. Outside an
isolated (about 20% chance) shower, southern Wyoming should remain
dry. Some of the storms across the north (mainly the Bighorn Basin
and Johnson County) could be on the stronger side, with gusty
outflow wind or hail. The better chances for strong to severe storms
occurs towards Johnson County and northern Natrona County.

A tight pressure gradient persists today as well, with afternoon
wind gusts 30 to 40 mph across the Wind Corridor, and lesser gusts
elsewhere. These gusts decrease into tonight. Precipitation
continues across the north tonight as the broad trough remains in
place. They should be on a decreasing trend, however, by Tuesday
morning. Isolated (15% to 30%) chances continue across the north
Tuesday, mainly over the mountains. Highs Tuesday will be similar to
that of today, maybe a few degrees higher.

An upper-low moving down from Canada and into the Dakotas brings
moisture ahead of it on Wednesday. Rain chances (20% to 50%) occur
over far northern Wyoming during the afternoon and evening. This
also brings a breezy to windy afternoon. As this low continues to
move down, cooler air makes its way into the area for Thursday, with
highs back into the 70s. Rain chances also continue across the north
and portions of central Wyoming. The night of the 4th is currently
looking dry as the afternoon convection ends around sunset
Thursday, but some lingering showers cannot be ruled out at this
time.

High pressure begins to build in over the western U.S. for this
weekend, favoring warmer and drier conditions. Long range models are
showing the possibility for some systems to pass over eastern
Wyoming, which may bring some rain chances; confidence is low at
this time.

&&

.AVIATION /06Z TAFS THROUGH 06Z TUESDAY/...
Issued at 954 PM MDT Sun Jun 30 2024

Showers and thunderstorms will linger through the overnight hours
with most terminals not seeing any impacts. KCPR would be the only
terminal that may see a stray shower or gusty outflow from any
nearby showers.

Monday morning, a cold front will move west to east across the
region. Showers are possible with the front, but confidence is not
high on intensity of these showers, so have included several PROB30
groups to account for any stronger showers or storms that might
occur along and behind the front. The cold front will not bring a
strong wind shift, but gusty west winds will occur ahead of and
behind the front for most terminals Monday morning. By midday,
additional showers and thunderstorms are expected to develop along
and behind the front. Most terminals will have a chance for showers
and storms through the end of the period. PROB30 groups have been
included at several terminals to highlight this threat. KJAC, KCOD,
and KWRL are the terminals that will likely see the most impact from
any showers or thunderstorms associated with the front. Expect to
see multiple rounds of showers and thunderstorms throughout the
period. Conditions will likely fluctuate from MVFR to IFR, as
showers and thunderstorms move through terminals. All terminals will
likely return to VFR conditions by the end of the TAF period.
Mountain tops will be obscured at times during the period,
especially as the front moves through the state.

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.

&&

$$

DISCUSSION...Wittmann
AVIATION...Dziewaltowski