517
FXUS65 KCYS 241006
AFDCYS

Area Forecast Discussion
National Weather Service Cheyenne WY
406 AM MDT Fri May 24 2024

.KEY MESSAGES...

- Strong wind gusts 50-60mph possible in the wind prone and gap
  areas of southeast WY today mid-morning through early
  afternoon. See the latest High Wind Warning Statement for
  further details.

- Precipitation chances Saturday and Sunday before winds return
  Sunday. A much warmer, milder week ahead as an upper-level
  ridge overtakes the region.

&&

.SHORT TERM /THROUGH SUNDAY/...
Issued at 340 AM MDT Fri May 24 2024

The windy weather pattern has slowly winded down overnight,
with areas over the I-80 Summit and western Nebraska being the
only regions remaining with wind gusts of 40-50+ mph as of 930Z.
The mid-latitude cyclone responsible for the strong winds over
our cwa, and severe weather across the Central Plains will move
out toward the Upper Midwest/Great Lakes area by much later
today. In its wake, we will see surface high pressure dominate
the region. Slightly cooler temperatures will be present, as
daytime highs in the 60s are forecast for today, and slightly
cooler in the higher terrain. Increasing clouds from the south
will move north by this evening, keeping temperatures slightly
elevated overnight.

Shortwave disturbances will propagate along the H5 flow aloft
for Saturday, and this is going to be our next opportunity for
rain showers and isolated thunderstorms. However, the energy
associated with the flow aloft, and lee-side troughing east of
the mountain ranges will limit the strength of any convection
that initiates. We will have the potential for a few locations
to see wetting rainfall in excess of 0.10 inches. This would be
well received as there are increasing concern for drought as
the late spring period continues.

Saturday night, model guidance is trending towards another weak
mountain wave event for southeast Wyoming. 700mb winds are
progged to creep north of the 50 knot threshold by 12Z Sunday.
In fact, some areas along the spine of the Laramie Range could
exceed 60-65 knots. This wind speed coupled with the
upward/downward motion from modeled omega fields depict a swath
of elevated to strong wind gusts reaching the surface. The areas
of Arlington, I-80 Summit, and Bordeaux are favored the most for
this to be realized. The eastern foothills off the Laramie Range
may also see the stronger wind gusts of 60+ mph from Sunday
morning into the early afternoon. Isolated rain showers in our
norther forecast zones are possible from Sunday morning into the
afternoon hours as the shortwave disturbance responsible for the
winds quickly ejects eastward. Daytime highs in the 60s and 70s
for the lower terrain will be expected, and it should be a
pleasant holiday weekend for those that plan to be outdoors.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
Issued at 340 AM MDT Fri May 24 2024

Surface frontal boundary looks to lay along a line from Kimball
to Wheatland to just north of Riverton Sunday evening. Upper
shortwave tracks across northeastern Wyoming Sunday evening
that may drive the cold front south into the central CWA.
GFS/ECMWF looks to be dry on PoPs through as this front shifts
south. If anything...maybe Converse and Niobrara Counties may
see a few showers early Sunday evening.

Memorial Day looking dry still as 500mb heights are on the rise
as a flat ridge builds into western and central Wyoming.

Upper ridge axis shifts east into western Nebraska and western
South Dakota Tuesday afternoon and evening. May start to see
increasing chances for showers Tuesday afternoon across our
western mountains and possibly as far east as Cheyenne into the
evening hours. Better chances Wednesday as next shortwave
begins to move into the western part of the state.

&&

.AVIATION /06Z TAFS THROUGH 06Z SATURDAY/...
Issued at 1006 PM MDT Thu May 23 2024

West northwest flow aloft will continue with winds decreasing
during the daytime on Friday as pressure gradients weaken.

Wyoming TAFS...Clear skies will prevail through Friday
afternoon, then ceilings will be around 15000 feet. Winds will
gust to 35 knots until 00Z.

Nebraska TAFS...Scattered to broken clouds around 10000 feet
will continue until mid morning Friday, then skies will become
clear. Winds will gust to 40 knots until 00Z.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...None.
NE...None.

&&

$$

SHORT TERM...BW
LONG TERM...GCC/AM
AVIATION...RUBIN