Spearfish, South Dakota 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

837
FXUS63 KUNR 112041
AFDUNR

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
241 PM MDT Fri Apr 11 2025

.KEY MESSAGES...

- Dry, warm, and breezy conditions continue today and Saturday.

- A spring system enters the northern plains later Saturday
  through Monday, bringing strong winds, cooler temperatures, and
  chances for precipitation.

- Warmer temperatures move back in mid-week.


&&

.DISCUSSION...(This Evening Through Friday)
Issued at 203 PM MDT Fri Apr 11 2025

Current upper air models show upper ridge over the northern and
central plains today. Surface chart depicts surface high shifted
over Iowa while surface low sits over the eastern MT/WY border.
Secondary cold front stretches from central MT southwest into
Idaho this afternoon. Temperatures currently sit in the upper 70s
across the area with breezy southerly winds.


Breezy south winds and dry conditions today has led to near-
critical fire weather for much of our plains counties this
afternoon. Winds will diminish late afternoon into the evening.
Upper ridge flattens out on Saturday as an approaching shortwave
crosses the PAC NW, and eventually into the northern plains on
Sunday. Surface low moves across the region early Saturday, with
slightly cooler temperatures behind it, though highs for Saturday
will still be in the mid 60s and 70s. Rain showers and an isolated
thunderstorm or two wiSoutherly winds will be breezy, sustained around  These strong
gusts are not expected to be frequent, and may be in the late
morning (before RH reaches 15%), and so the wind gusts may not
align well enough with the driest afternoon RH to warrant a Red
Flag Warning. However, it will be close, and conditions will be
near- critical.ll be possible Saturday afternoon and evening. MU
CAPE is modest, but with strong shear and decent inverted V
soundings, a strong to severe storm may be possible in the late
afternoon early evening timeframe, with winds being the main
threat.

Precipitation chances will continue into the Saturday night through
Monday morning. Early Sunday, main cold front crosses the region,
with models showing strong pressure rises behind the front. Some
model inconsistency with how much, as the NAM is showing 5-7
mb/3hr pressure rises, while the GFS points to 3-5 mb/3hr rises.
Either way will likely need widespread wind headlines for Sunday.
Model QPF keep the bulk of any accumulating precipitation Saturday
through Monday morning to the north of our CWA. LREF probability
for 0.1" 24hr QPF sits in the 50 to 80 percent range for
northwestern SD, dropping off quickly to the south. The better
chances to see accumulating precipitation will range from far
northeastern WY to the northern Black Hills and northwest SD.
Seasonable temperatures follow the cold front, with highs on
Sunday in the 50s to low 60s. Cooler temperatures will continue
the first half of the half of the week before mild ridging builds
over the northern plains mid- week, warming temperatures up some.

&&

.AVIATION...(For the 18Z TAFS Through 18Z Saturday)
Issued At 1033 AM MDT Fri Apr 11 2025

VFR conditions are expected through the forecast period.

&&

.FIRE WEATHER...
Issued At 203 PM MDT Fri Apr 11 2025

Near critical fire weather conditions today with breezy southerly
winds and RH values dipping into the mid and upper teens.
Mild and dry weather will continue Saturday, but nearly as dry
(min RH 20-30%) and not very windy. Very strong winds arrive
early Sunday behind a cold front.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...None.
WY...None.
&&

$$

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