253
FXUS65 KRIW 152151
AFDRIW

Area Forecast Discussion
National Weather Service Riverton WY
351 PM MDT Wed May 15 2024

.KEY MESSAGES...

- Isolated mountain showers going forward each afternoon and
  evening.

- Elevated fire weather Friday and over the weekend.

- Next system will come in Sunday night into early next week.

&&

.DISCUSSION...
Issued at 1216 PM MDT Wed May 15 2024

Current IR depicts the shortwave that affected the CWA pushing
southeast into the high plains. Improved skies and upper level
ridging has begun to extend across the upper Rockies. The high
is centered off the west coast continuing to build with
increasing convergence aloft. Being a more zonal flow across
the CWA with the main finger of the PFJ well to the north into
Canada. More of a westerly flow induced rain showers this
afternoon across the Divide and points west with no impacts
expected. Less wind and warmer temperatures will continue
through the weekend with a series of weak shortwaves skimming
the northern CWA. Weak showers and a couple isolated storms
possible for the higher terrain but overall quieter weather
pattern.

Friday and over the weekend will see the warmest temperatures
along with increasing southwest winds ahead of the next system.
Wind gusts will exceed 30 mph in the wind prone areas that will
increase fire weather risk to elevated for these areas as
humidity drops due to these increasing temperatures. However,
with green-up still ongoing, minor impacts expected but keeping
an eye out for the situation at hand.

Sunday night will see a deepening trough over the Pacific
northwest dropping down from the GOA. Increasing divergence
aloft will allow it do deepen quite a bit as it extends
southward through the Sierra Nevadas. Impacts for western zones
will start as early as Monday morning with mountain snow and
valley rain before spreading eastward later in the day. Longer
term models indicate the trough to close off and spin a series
of shortwaves through the upper Rockies through much of next
work week before kicking off to the east by next Friday and into
the following weekend. Based upon this, it seems to be due to
the jet cutting off to the north pinching off the PVA into the
low as it fills and gets embedded into the southern portions of
the jet stream. Time will tell, but this looks to be the next
system of interest. With it, will come more seasonable to just
under average temperatures and wetter conditions to come. Stay
tuned for updates in the coming days as specifics are for sure
uncertain at this time.

&&

.AVIATION /00Z TAFS THROUGH 00Z FRIDAY/...
Issued at 351 PM MDT Wed May 15 2024

Some SCT050 clouds will hang around at many terminals for a
couple hours this evening as isolated rain showers diminish this
evening. Prevailing VFR conditions will remain in place through
the TAF period.

Wind will be light (less than 8 knots) today into Thursday morning.
Wind will begin to increase at KCPR late Thursday morning from the
west, with gusts around 20 knots through Thursday afternoon. Wind
will increase at all terminals Thursday afternoon, with sustained
wind around 10-15 knots and gusts around 20 knots through the
afternoon hours.

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...Lowe
AVIATION...Rowe