000
FXUS65 KRIW 111738
AFDRIW

Area Forecast Discussion
National Weather Service Riverton WY
1138 AM MDT Thu Apr 11 2024

.KEY MESSAGES...

- Warming temperatures today through Sunday. Most of the area
  will remain dry, though some light showers are likely (40%)
  over and near the mountains Friday and Saturday.

- Gusty wind and low humidity will lead to widespread elevated
  fire weather conditions Friday through the weekend.

- Precipitation chances increase Sunday as the next system
  approaches. A return to cooler and wetter weather is favorable by
  the middle of next week.

&&

.DISCUSSION...
Issued at 352 AM MDT Thu Apr 11 2024

A warming trend begins today as ridging pushes into the region. This
will lead to a dry and mostly sunny day, with temperatures peaking
in the 50s and 60s for most lower elevation locations. It will be a
little breezy in the usual spots, but nothing out of the ordinary by
Wyoming standards.

Flow aloft will become southwesterly on Friday as a deepening low
drops south off the coast of California. This will advect in even
warmer temperatures through the weekend, with highs generally
peaking 15 to 20 degrees above normal for this time of year. This
will also come with an increased, mixing southwest wind all three
days. Elevated to near-critical fire weather conditions will be
widespread through the weekend, with Sunday the most likely day to
need fire weather highlights across portions of central and southern
Wyoming. There should also be just enough Pacific moisture and
shortwave lift for some shower activity Friday and Saturday, with
the best chances across the mountains.

The precipitation forecast becomes more tricky on Sunday as the
low mentioned above approaches the Rockies. Recent trends have
slowed the arrival of this system into early next week, and have
also split it into one or two weaker systems. There is also
still plenty of uncertainty on where this will track, with a
south trend becoming more apparent in some model solutions.
Regardless, moisture should start to increase over the area
Sunday afternoon; the forecast reflects the uncertainty with
generally light PoPs for the mountains, spreading to lower
elevations Sunday evening. Ensemble 500mb cluster guidance
continues to favor the low to pass to our south through Monday,
followed quickly by a broader trough dropping south out of
Canada. This second trough may end up being the main event, as
this scenario would lead to widespread precipitation and much
cooler temperatures as it sweeps south through midweek. In
summary - while details are fuzzy on the timing and strength of
any impacts, a change back to cooler and wetter conditions
appears favorable by the middle of next week.

&&

.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 1137 AM MDT Thu Apr 11 2024

VFR conditions expected for the entirety of the period for all
terminals. Expect northwest winds to increase west of the
Divide through this afternoon. Gusts up to 20kts are expected at
KBPI and KPNA with gusts up to 25kts at KRKS. East of the
Divide, winds will remain relatively light (less than 10kts),
though KCPR may see a sustained southwest wind around 12 to
15kts through the first hour or two of the period before winds
become northwesterly later in the afternoon. Increasing upper
level clouds are expected after sunset this evening ahead of an
approaching weak shortwave.

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...Myers
AVIATION...Hensley