Alliance, Nebraska 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

315
FXUS65 KCYS 152258
AFDCYS

Area Forecast Discussion
National Weather Service Cheyenne WY
Issued by National Weather Service Riverton WY
458 PM MDT Thu May 15 2025

.KEY MESSAGES...

- Windy conditions continue today and tomorrow for most of
  southeast Wyoming and western Nebraska with gusts 40-60 mph
  possible.

- Temperatures near to just below seasonable expected through
  early next week.

- Next chances for showers and thunderstorms over the weekend
  with another low-end risk of stronger storms, particularly on
  Sunday.

&&

.SHORT TERM /THROUGH FRIDAY/...
Issued at 232 PM MDT Thu May 15 2025

Radar and satellite data shows scattered showers and thunderstorms
popping up across the region this afternoon on the backside of
a deep low moving into the Great Lakes region, with embedded
disturbances rounding the periphery of this system. Looking over
the next several hours, while some meager instability is
present as mesoanalysis shows MUCAPE values around 500 J/kg and
low level lapse rates around 9.5-10 C/km, forcing is not present
and inverted V soundings will assist in keeping showers and
storms high based, but could also produce some gusty localized
gusty winds. Otherwise scattered precipitation should persist
through the afternoon with activity subsiding as diurnal heating
ends during the evening. A few stronger wind gusts have also
been noted this afternoon primarily along the foothills of the
Laramie Range and just below the summit near I-80. Although not
frequently hitting the 58+ mph gusts needed for high wind
criteria, several have occurred and being near a major corridor
has prompted a high wind warning through 4 PM. This could be
aggressive, but would rather be on the safe side.

Winds should also calm down tonight, but will gust again
tomorrow to around 40-50 mph, though the 700mb jet will max out
along the borders of SD/WY/NE, so a few stronger gusts
potentially breaching the high wind warning criteria of 58+ mph
could be possible for northern counties of the Nebraska
Panhandle.. Otherwise Friday should be a quieter day as
precipitation exits the region and skies see some clearing under
a weak transient ridge.

&&

.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
Issued at 232 PM MDT Thu May 15 2025

The long term sees active weather return as our next Pacific
system moves into the region over the weekend, with showers and
thunderstorms likely. Scattered precipitation is expected on
Saturday, but more widespread coverage of activity is
anticipated on Sunday alongside better chances of some stronger
thunderstorms. Favorable instability in excess of 1000-1500 J/kg
of MUCAPE with forcing from frontogenesis and cyclogenesis
should promote a few stronger storms, even if wind shear has
declined as of this update. It would not be surprising to see a
marginal risk encompass our region on Sunday with some breezy
winds or small hail possible, but stronger activity to warrant
higher risk seems unlikely as the environment will just not be
there. But deep moisture advection from easterly flow should
help produce fairly widespread precipitation for the day with
moderate to some locally heavier accumulations not out of the
question. That being said, QPF values seemed a little too
aggressive this early, with a 2 inch bullseye just south of
Chadron noted, so those were toned down at this time.

Early to middle of next week our region will be on the
backside of this aforementioned system, with some scattered
showers still possible Monday and Tuesday, but they will be on
the decline. Temperatures should cool notably with highs
expected to be around 5-10 degrees below normal for this time of
year with highs in the 50s, but a warming trend will bring us
back to near normal by the middle of the week. Some breezier
winds could be possible with gusts around 40 mph, but stronger
winds like what we see today and tomorrow are not as likely at
this time. We should otherwise experience warming and clearing
skies to bring a pleasant end to the long term as we move away
from the disturbed weather of the end of this week and this
weekend.

&&

.AVIATION /00Z TAFS THROUGH 00Z SATURDAY/...
Issued at 458 PM MDT Thu May 15 2025

All terminals to be VFR through the forecast period. The primary
aviation hazard will remain gusty west to northwest wind on the
backside of a low pressure system in the Dakotas. Widespread 25G35kt
speeds with higher gusts around 40kts slowly diminish to 12-24kts
between 01Z-03Z/Friday before speeds ramp up again during the
morning Friday, generally around 14Z-15Z. Scattered showers and
embedded thunderstorms track east-southeast across the region
through sunset Thursday. Given synoptic winds, any stronger storm
could throw out gusts approaching 50kts. The main weather system in
the Dakotas tries to wrap back southward Friday morning, and may
bring some low clouds and light rain to KCDR between 12Z-18Z/Friday.
These clouds and light rain could shift as far south as KAIA.

&&

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

&&

$$

SHORT TERM...CG
LONG TERM...CG
AVIATION...WFO-RIW