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000
FXUS65 KRIW 102146
AFDRIW

Area Forecast Discussion
National Weather Service Riverton WY
346 PM MDT Wed Apr 10 2024

.KEY MESSAGES...

- Lingering showers exit the region this afternoon and evening
  as a ridge builds behind the exiting shortwave.

- Unseasonably warm temperatures and quiet weather are expected
  through the weekend.

- Elevated Fire Weather expected Friday and Saturday across the
  Wind Corridor.

- Chances for cooler weather and widespread precipitation
  increase after Sunday, but uncertainty remains high regarding
  details of the incoming trough at this time.

&&

.DISCUSSION...
Issued at 216 PM MDT Wed Apr 10 2024

A few lingering showers, mainly virga showers at this point, are
exiting Natrona County as of 2 PM. This morning, these showers
produced a dusting of snow in a few places, most notably Casper, and
fell as light rain in others (including the Bighorn Basin). This
shower activity was associated with a passing shortwave, which will
completely exit the region later this evening. Also as a result of
the shortwave, it is a bit cooler and breezier today across the
region. Gusty northwest winds (gusts 40 to 50 mph at times) have
been occurring across the Bighorn Basin and northern Johnson County
through much of the day, with lighter, but still breezy northwest
winds across the Wind River Basin, Green River Basin, and Sweetwater
County. These winds will diminish overnight as the shortwave exits.

Behind the shortwave, there is not a whole lot to talk about through
the weekend thanks to building high pressure. If you have been
itching to get outdoors and enjoy some warm, Spring sunshine, this
is your chance! Temperatures will warm to values that are 15 to 20
degrees above normal by Friday afternoon and similar warm
temperatures will continue through the weekend. Southwest winds
increase Friday and especially Saturday, leading to elevated fire
weather concerns across the southwest and into southeast Fremont and
Natrona Counties. Gusts 25 to 35 mph will be possible both
afternoons for the aforementioned Wind Corridor areas. The warm
temperatures will also prompt low elevation snowmelt for the western
valleys where 1 to 2 feet of snowdepth still exists in the lower
elevations. River rises are expected, but are not expected to exceed
flood stage (less than 5% chance of exceedance).

The Spring warmth and dry weather does not look to stick around too
long though. A Pacific low approaches the CA coast by Friday
evening, ejecting a very quick-moving shortwave across the north.
There could be some very light, terrain enhanced showers (likely of
the rain variety) across the far western mountains Friday afternoon
as a result, but otherwise no impacts are expected. As the low
pushes on shore however, precipitation chances increase across the
west for Sunday. Again though, any precipitation chances look to be
mainly diurnally and orographically driven and focused mainly over
the far western mountains Sunday afternoon. Little to no
accumulations or impacts are expected.

By Monday afternoon, the aforementioned Pacific low looks push
farther into the CONUS. This is where models begin to significantly
diverge and uncertainty increases. A second low looks to dip out of
Canada brining much cooler air and more moisture with it. The timing
and track of the two lows, how they interact, and what that means
for precipitation type and amount is where the uncertainty lies. As
of now, there does look to be increasing chances for widespread
precipitation and cooler weather for the early part of next week
through mid-week, but details are uncertain at this time.

&&

.AVIATION /00Z TAFS THROUGH 00Z FRIDAY/...
Issued at 343 PM MDT Wed Apr 10 2024

Some midlevel clouds continue to move across the KCOD and KCPR
areas this afternoon. A couple light showers may continue the
next couple hours, but once daytime heating is gone, showers
should be quickly ending and lower cloud decks should be
thinning out. All sites should be CLR overnight, with light and
variable winds. Mostly clear skies continue through the day
Thursday. Gusty winds will be limited to the KRKS/KPNA/KBPI
area, with gusts running about 20kts in the afternoon.

&&

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

&&

$$

DISCUSSION...Hensley
AVIATION...Straub