274
FXUS65 KCYS 120541
AFDCYS

Area Forecast Discussion
National Weather Service Cheyenne WY
1141 PM MDT Sun May 11 2025

.KEY MESSAGES...

- Widely scattered afternoon showers and thunderstorms today
  will have the potential to produce strong, gusty winds.

- Near record high temperatures are expected through Tuesday.

- The next storm system will bring cooler temperatures and
  stronger winds mid-week, but the precipitation outcome is more
  uncertain.

&&

.SHORT TERM /THROUGH MONDAY NIGHT/...
Issued at 342 PM MDT Sun May 11 2025

KCYS radar currently shows widely scattered light showers across
parts of southeast Wyoming. Although not impressive on radar, these
showers are closer to dry microbursts, producing sprinkles at most
with strong wind gusts. Several Special Weather Statements have
already been issued for gusts over 50 MPH. These dry microbursts
will continue through the afternoon and into the evening hours as
the very dry surface persists with model soundings showing deep
inverted-v profiles. Mid-level moisture will gradually be replaced
by drier air aloft overnight, putting an end to showers.

Above average temperatures continue into Monday as weak ridging
aloft struggles to stay in place. Southwest flow will allow for warm
air advection into the region, increasing 700 mb temperatures to
+12C, with is in the 90th percentile for NAEFS climatology. The
anomalously warm temperatures could lead to a few record high
temperatures across the area, with 90s becoming a bit more
widespread across the Nebraska panhandle and the North Platte
River Valley. Ample sunshine tomorrow will definitely add to the
heat, but breezy conditions may make it feel bearable. It will
be especially breezy west of the Laramie Range with a low-level
jet over central Wyoming. Rawlins will likely be the windiest
spot with gusts over 45 MPH possible throughout the day. It is
worth mentioning that in-house guidance is pinging high wind
potential for Rawlins during the day tomorrow. However, winds
aloft only max out at around 40 kts with decent gradients. There
is good subsidence, so these winds will likely make it down to
the surface, but high winds are unlikely at this time.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
Issued at 342 PM MDT Sun May 11 2025

Tuesday...The flow aloft strengthens in advance of the next
approaching shortwave trough. Temperatures look to be slightly
cooler with an increase in low level moisture and cloud cover.
Continued dry with warm temperatures aloft providing convective
inhibition.

Wednesday...As a progressive shortwave trough aloft and its
associated cold front move across the forecast area, we will see
scattered afternoon and evening showers and thunderstorms, along
with cooler temperatures from the upper 50s west of I-25, to the
lower 60s to lower 70s further east.

Thursday...Cooler and breezy in the wake of the cold front with west
northwest flow aloft and 700 mb temperatures near 3 Celsius. Looks
like enough low and mid level moisture to produce scattered
afternoon and evening showers and thunderstorms.

Friday...West flow aloft develops and with 700 mb temperatures near
4 Celsius, maximum temperatures will be in the 60s to near 70
degrees. A bit less available moisture, so areal coverage of showers
and thunderstorms will be reduced.

Saturday...The flow aloft turns westerly, and with a slight increase
in mid level temperatures, high temperatures will show a warming
trend. Still enough low and mid level moisture for scattered
afternoon and evening showers and thunderstorms.

Sunday...Southwest flow aloft develops in advance of the approaching
shortwave trough. With increasing low and mid level moisture, and
lift generated by a passing shortwave trough aloft, scattered to
numerous showers and scattered thunderstorms will develop, focused
along a low level convergence axis and surface trough along the
Wyoming-Nebraska state line.

&&

.AVIATION /06Z TAFS THROUGH 06Z TUESDAY/...
Issued at 1137 PM MDT Sun May 11 2025

VFR conditions expected for the forecast period. Lingering
high-based showers will continue to have the potential to
produce gusty winds and a few sprinkles over the next few hours,
but should wane by around 09z. Expect gusty winds Monday
particularly near KRWL, with another southerly low level jet
event anticipated to begin Monday evening in the Nebraska
panhandle.

&&

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

&&

$$

SHORT TERM...SF
LONG TERM...RUBIN
AVIATION...MN