Area Forecast Discussion
Issued by NWS Rapid City, SD

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46

000
FXUS63 KUNR 142043
AFDUNR

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
243 PM MDT Thu Mar 14 2024

.KEY MESSAGES...
204 PM MDT Thu Mar 14 2024

-Fire Weather Watch over parts of northwestern SD Friday
 afternoon.
-Dry weather and periods of breezy/windy conditions may lead to
 elevated fire weather conditions at times through the weekend an
 into next week.

&&

.DISCUSSION...(This Evening Through Thursday)
Issued at 204 PM MDT Thu Mar 14 2024

Low stratus and breezy/windy northerly winds continue over much
of the forecast area this afternoon due to cooler air flowing
into the region behind a weak cold front this morning. Temperatures
on the plains are mainly in the 30s, with 40s to lower 50s in the
areas that remained mostly cloud free during the day, like much
of the Black Hills and parts of south central South Dakota.

Latest analysis shows an upper trough over the forecast area this
afternoon, extending SW to the upper low, currently over southern
California. At the surface, a region of high pressure is centered
over ern MT/wrn ND extending in a narrow band southward across
eastern WY/CO. The surface high sagging southward into the region
is tightening the pressure gradient leading to breezy/windy
conditions. The windiest locations this afternoon are just to the
east of the Black Hills from Rapid City to Fairburn where gusts
of 35-40 mph are common. The winds will diminish during the late
afternoon/early evening and the stratus will continue to decrease
in coverage overnight as the surface high settles over the area.

On Friday, the surface high will move off to the south as a low
pressure system moves from Manitoba toward the Great Lakes.
Dry westerly downslope winds will develop, becoming gusty in the
afternoon due to the tightening of the surface pressure gradient
over northwestern South Dakota. Have issued a Fire Weather Watch
for that area on Friday.

With the upper ridge remaining in place over the western CONUS, a
series of dry and fast moving shortwaves will cross the region in
northwesterly flow aloft. This will result in a moisture-starved
low level baroclinic zone oscillating over the Dakotas. Periods
of breezy/windy conditions will occur as temperatures wiggle east
and west with each passing front. Ensemble guidance indicates
less than 20% chance of >0.1" QPF through the first half of next
week. Much needed moisture is very unlikely to occur.

&&

.AVIATION...(For the 18Z TAFS Through 18Z Friday)
Issued At 1129 AM MDT Thu Mar 14 2024

Widespread MVFR to LIFR conditions in low stratus, some light
snow, and areas of fog should diminish this afternoon through
tonight, with VFR conditions anticipated area-wide by 06z, if not
before. Have opted to hedge towards the more conservative guidance
in terms of timing of improvement given bias among many models in
eroding low stratus too quickly. Nonetheless, given model
consensus of improvement to VFR for most by 00z, I may be a little
too conservative.

At any rate, breezy northerly winds should also diminish this
evening, becoming light and variable for most overnight. Breezy
winds will return tomorrow for much of the area, this time out of
the west and southwest.

&&

.FIRE WEATHER...
Issued At 204 PM MDT Thu Mar 14 2024

Dry westerly winds will become gusty over parts of northwestern
South Dakota on Friday afternoon. The combination of low relative
humidity and gusty winds may lead to critical fire weather
conditions there on Friday afternoon. Conditions will improve on
Friday evening.

Elevated fire weather conditions may persist into next
week due to the return of drier air and periods of gusty winds,
especially on Monday.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...Fire Weather Watch from Friday afternoon through Friday evening
     for SDZ328-330.
WY...None.
&&

$$

DISCUSSION/KEY MESSAGES...10
AVIATION...Sherburn
FIRE WEATHER...10


USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.