271
FXUS65 KRIW 051114
AFDRIW

Area Forecast Discussion
National Weather Service Riverton WY
514 AM MDT Wed Jun 5 2024

.KEY MESSAGES...

- Warm, dry, and windy conditions expected today leading to
  elevated fire weather concerns this afternoon.

- Warming trend continues through the end of the week. Showers
  are possible on Friday (25-50 percent), but most of the area
  will remain dry.

- Weekend will see a better chance of afternoon showers.

- Increased mountain snowmelt expected given warming temperatures.

&&

.DISCUSSION...
Issued at 341 AM MDT Wed Jun 5 2024

Warm and dry conditions are expected across the area today as
ridging increases over the region. This will mark the beginning of a
warming trend through the end of the week, with the potential for
three consecutive days of the warmest temperatures of the year
thus far for many locations. Today, highs will peak 8-9 degrees
above normal, or generally in the upper 70s west of the Divide
and lower 80s east. The one exception today will be across the
northern half of Johnson County. This area will get clipped by a
cold pool associated with a weak front dropping south out of
Montana, keeping high temperatures more around normal.

Otherwise, with aligned 700mb and upper level flow sandwiched
between the ridge and a trough to our east it will be another
windy day for the area. Wind will ramp up through the morning,
with west/northwesterly gusts of 30+ mph across western,
central, and southern Wyoming. The Bighorn and Powder River
basins will see a more northerly wind as the front pushes south
through the afternoon. With the dry and windy day, elevated
fire weather conditions are expected for much of the area
through the afternoon. Wind will quickly decrease with sunset.

Temperatures warm further on Thursday, with nearly all lower
elevations seeing temperatures in the 80s. A few locations may
reach 90. With the warmer and drier airmass, humidity will drop
to around/below 15 percent, keeping elevated fire weather
conditions going. Lower wind speeds will play a mitigating
factor in this, however.

Models are hinting at a weak shortwave arriving in the Thursday
night/Friday timeframe. This added lift combined with slightly
increased Pacific moisture will return shower chances to the area,
with the best chances Friday afternoon. However, chances remain
on the lower side (generally below 50 percent), and most of the
area will be dry and warm once again. Given the warming
temperatures through the week, rivers and streams will continue
to be monitored for flooding potential as mountain snowmelt
increases.

The overall ridging pattern is currently favored to persist through
the weekend, though with continued disturbances moving through the
flow. Accordingly, the forecast reflects a still warm but slightly
cooler weekend, with better chances for afternoon convection both
days.

Model solutions diverge dramatically by early next week. Ensemble
cluster mean guidance currently favors anomalously high 500mb
heights to persist through next week. This would keep warm and
mostly dry conditions across the area.

&&

.AVIATION /12Z TAFS THROUGH 12Z THURSDAY/...
Issued at 511 AM MDT Wed Jun 5 2024

Clouds near the mountains should continue to decrease through
the morning. Most of these clouds will linger over the
mountains. Winds will increase again this morning as gusts
around 25 kt will return across the area between 14Z and 18Z.
Gusts of 30 to 35 kt will occur at KCPR, KRKS, KRIW and KBPI
after 18Z. These winds will once again decrease by 02Z, becoming
12kt or less. A notable shift to the north- northeast will also
occur for terminals east of the Divide after 00Z. VFR conditions
will continue through the period.

Please see the Aviation Weather Center and/or CWSU ZDV and ZLC for
the latest information on smoke, icing, and turbulence forecasts.

&&

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

&&

$$

DISCUSSION...Myers
AVIATION...Hattings