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000
FXUS65 KRIW 181721
AFDRIW

Area Forecast Discussion
National Weather Service Riverton WY
1121 AM MDT Thu Apr 18 2024

.KEY MESSAGES...

- Remaining cool today, with mountain snow showers.

- Warming temperatures this weekend, returning back to near-
  normal, and even above normal by Sunday.

&&

.DISCUSSION...
Issued at 103 AM MDT Thu Apr 18 2024

The cold front that brought snow and colder temperatures is heading
eastward this morning, as evident on current water vapor imagery.
Almost all snow will be done falling by sunrise, with 10% to 30%
chances of lingering snow showers in the Wind River Mountains
through this morning. As for the cold temperatures, those stick
around today. Highs today look to peak in the lower 40s for most.
The warmer locations will be the southern Green River Basin and
Sweetwater County, with temperatures closer to the 50 degree mark.
For reference, most locations` normal highs this time of year are
firmly in the 50s, nearing 60.

Northwest flow aloft brings some weak instability to the region as
well today. Snow showers are possible (30%-70% chances) for the
western mountains (greatest chances for the Absarokas) and the
Bighorn Mountains. Not expecting any impacts from this, though there
is the possibility (70%) for the higher elevations of the Absarokas
to receive an additional 1 to 4 inches.

A very similar scenario continues for Friday. West-to-northwest flow
again allows afternoon snow showers to develop for the western and
northern mountains. Temperatures increase a few degrees for southern
Wyoming, but should be very comparable across the rest of the area.

A transitory ridge follows, bringing warmer temperatures for this
weekend. Temperatures are closer to normal for Saturday, with the
chance for above normal temperatures returning for Sunday; current
NBM has 70% to 90% chances for the lower elevations to go above 60
degrees (which would be above normal for most places). Jackson Hole
remains cooler.

The next weather feature of note is a shortwave passing through
around Sunday/Monday, pushing the ridge out. This brings
precipitation chances for the northern half of the area, mainly the
mountains. Nothing currently looks impactful with this system.
Temperatures would also dip a little should this system move through
as currently projected.

&&

.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 1120 AM MDT Thu Apr 18 2024

A post-storm system environment remains over western and central
Wyoming today with cooler than normal temperatures with boundary
layer moisture and weak instability. Light showers dissipated
quickly this morning with a few areas continuing this afternoon
over the mountains and foothills areas, but not expected at any
TAF sites. General VFR conditions are expected through the
forecast period, but patchy MVFR conditions are expected through
the afternoon. Thicker clouds around some of the foothills
areas will obscure the mountains into Friday morning. Winds are
generally NW-N-NE today though SW-W-NW breezy winds will return
to southwest WY this afternoon and evening.

Conditions will be quite similar on Friday with light showers
over the northern and north-central mountains and VFR/MVFR
conditions in some of the central WY basins. Winds will be more
east-northeast on Friday with high pressure dropping down over
SE Montana.

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...McDonald