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000
FXUS65 KRIW 180704
AFDRIW

Area Forecast Discussion
National Weather Service Riverton WY
104 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 /06Z TAFS THROUGH 06Z FRIDAY/...
Issued at 1104 PM MDT Wed Apr 17 2024

West of the Divide...KBPI/KJAC/KPNA/KRKS Terminals.

In general, VFR conditions prevail through the forecast period. Back
door cold front on the KRKS doorstep will bring east-northeast 10-
15kt wind and a 30-50 percent chance of MVFR ceilings between 10Z-
16Z. Westerly wind does return to the southwest terminals mid-
afternoon Thursday, with speeds 10-15kts. Mountain tops remain
occasionally obscured until 16Z.

East of the Divide...KCOD/KCPR/KLND/KRIW/KWRL Terminals.

A combination of shortwave energy and jet support has generated
light snow across the central basins from KRIW/KLND to KCPR
Wednesday evening. The best chance for MVFR conditions at these
terminals lasts until 08Z, but flurries, low-end VFR, and
intermittent MVFR could persist until around 12Z-15Z. KCPR and KLND
would see these pesky conditions linger longest. All terminals to be
VFR by 15Z. Instability showers form over the mountains Thursday
afternoon with mid-cloud decks for many areas through the remainder
of the period. KCOD would have the best opportunity to see a brief
shower, but confidence is low. Mountain tops occasionally obscured.

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...
Winter Storm Warning until 6 AM MDT early this morning for
WYZ008-009.

&&

$$

DISCUSSION...Wittmann
AVIATION...CNJ