745
FXUS65 KRIW 011745
AFDRIW

Area Forecast Discussion
National Weather Service Riverton WY
1145 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 /18Z TAFS THROUGH 18Z TUESDAY/...
Issued at 1145 AM MDT Mon Jul 1 2024

A weather system, with an associated cold front is passing through
the area today. As a result scattered rain showers and thunderstorms
will develop/have developed and will continue to develop across the
northern half of the area this afternoon through tonight. Terminals
most likely to be impacted by these showers and storms are KJAC,
KCOD, and KWRL where TEMPO groups are included in the TAFs. The cold
front is passing through the area this afternoon/evening and wind
will shift northerly once it passes. An area of rain is likely (60-
70%) to pass over KCOD early Tuesday morning. Conditions will remain
VFR through the TAF period, excluding terminals where a thunderstorm
moves directly overhead, which will result in reductions in VIS to
MVFR (possibly IFR 20-30% chance).

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

&&

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

&&

$$

DISCUSSION...Wittmann
AVIATION...Rowe