FXUS63 KUNR 152350
AFDUNR

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
550 PM MDT Wed Apr 15 2026

.KEY MESSAGES...

- Elevated to critical fire weather conditions expected for
  Thursday.

- Cold front moves through later Thursday, bringing rain/snow
  behind it.

- Warming trend over the weekend with mostly dry conditions
  Saturday through middle of next week.

&&

.DISCUSSION...(This Evening Through Wednesday)
Issued at 1230 PM MDT Wed Apr 15 2026

Current surface analysis shows high pressure over southeastern SD,
with a weak surface trough stretching from northwest SD down into
eastern Wyoming. Upper air analysis depicts shortwave over NE/KS
region, upper low over the PAC NW, with near west/east flow over
the forecast area. Temperatures currently sit in the 60s to low
70s, with light winds. Recent satellite images show mid/high
clouds expanding into the forecast area from the west.

Elevated to near-critical fire weather parameters continue this
afternoon, as warm and dry conditions persist. Thursday will see
some areas reach critical fire weather conditions ahead of a cold
front, as temperatures reach into the 70s and low 80s, with winds
15 to 25 mph, and gusts up to 40 mph in the late morning and
afternoon. Cold front moves through from northwest to southeast
Thursday afternoon into the evening, bringing gusty northwest
winds and chances for rain/snow through mid-day Friday. Any
accumulating snow amounts will be tricky given the time of year,
and temperatures hanging near freezing for some areas. Highest
potential for accumulating snowfall is expected in parts of
northeastern Wyoming into the central and northern Black Hills,
where NBM probability of 2" or more ranges between 30 to 70
percent. Widespread light QPF is expected, with the highest
ranges (0.05" - 0.4") stretching from northeastern WY into
northwestern SD. Current model runs show a small potential for low
end Winter Weather Advisory headline for some areas Thursday
night, but again chances are small. Main precipitation event moves
out mid-day Friday, but some light precipitation could linger for
some areas (generally Black Hills into southwest SD) into
Saturday.

After this system moves through, mostly dry conditions return late
Saturday through middle of next week. Upper ridge builds over the
western CONUS through the weekend as well, resulting in a warming
trend back to 10-20F above normal. Longer range models point to
the potential for more active weather the latter half of next
week, but will have to wait and see how model agreement works out.

&&

.AVIATION...(For the 00Z TAFS Through 00Z Thursday Evening)
Issued At 535 PM MDT Wed Apr 15 2026

VFR conditions are expected through tonight. A cold front will
move in Thursday, affecting KGCC first (15Z) then KRAP (21Z).
Winds will be gusty through tomorrow and shift throughout the day
before landing NNW behind the front. MVFR conditions may develop
at KGCC owing to rain/snow behind the front.

&&

.FIRE WEATHER...
Issued At 1230 PM MDT Wed Apr 15 2026

Elevated fire weather conditions continue this afternoon across
much of the area as RH falls into the teens to low 20s. Best
overlap of low RH and stronger winds forecast across southern
Campbell and Weston Counties in WY through southwestern SD.
Conditions remain below thresholds for any fire weather
highlights today.

A Red Flag Warning has been issued for Thursday for the Weston
County plains through southern SD as stronger southwest winds will
develop ahead of a cold front. Daytime minimum RH will fall as
low as 12-14 percent Thursday. Timing of the cold front as well as
mid-level clouds ahead of the front and spotty high- based
showers may complicate things a bit by keeping temperatures a bit
cooler and RH higher. However, plan for at least elevated to
near- critical conditions Thursday.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...Red Flag Warning from noon MDT /1 PM CDT/ to 7 PM MDT /8 PM CDT/
     Thursday for SDZ321-322-325-326-332>335.
WY...Red Flag Warning from noon to 7 PM MDT Thursday for WYZ317.
&&

$$

DISCUSSION/KEY MESSAGES...Dye
AVIATION...Schweigert
FIRE WEATHER...Dye