000
FXUS63 KUNR 170404
AFDUNR

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
1004 PM MDT Thu May 16 2024

.KEY MESSAGES...

- Unsettle pattern continues through the period.

- Very warm Friday. Late day thunderstorms with cold front could 
  bring some locally strong wind gusts. 

&&

.DISCUSSION...(This Evening Through Thursday)
Issued at 1220 PM MDT Thu May 16 2024

Water vapor shows upper low over southern BC with flat ridge 
extending from the Pac NW through the Northern Plains. At the 
surface, weak trof covers the western Dakotas. Early afternoon 
temps are in the 60s/70s with congested cu over the Black Hills.

A weak short wave in the westerly flow aloft will bring a few
light showers/storms from the Black Hills into northwest SD this
afternoon and evening, but moisture/instability is fairly
insignificant. 

Low level thermal ridge peaks on Friday for very warm temps, close
to 90 in some areas east of the Black Hills. More significant
short wave crosses the Northern Rockies in the afternoon and 
Northern Plains overnight, driving a Pacific cold front through 
the area. Scattered thunderstorms forming along the front, 
especially in and north of the Black Hills, could pose a wind a 
threat given the expected inverted-v soundings. Post frontal winds
should be near advisory for a period of time by evening and 
overnight, especially across northwest SD. 

Drier/cooler/breezy conditions expected Saturday in wake of Friday
night's cold front. Next short wave crosses the Northern Rockies
Sunday, with low level thermal ridge peaking again across the area
for another warm day. Associated cold front moves through late in
the day for another chance for showers/storms. 

Mean trof across the northwest and north-central CONUS through
next week will keep conditions unsettled with cold fronts moving
through nearly every day. 

&&

.AVIATION...(For the 06Z TAFS Through 06Z Friday Night)
Issued At 1004 PM MDT Thu May 16 2024

Isolated showers will be possible tonight across portions of the 
western SD plains, then again across the CWA Friday afternoon and
evening. The main threat with the storms is expected to be strong
winds. Other than any brief MVFR conditions near any precipitation,
VFR conditions are expected through the TAF period. Southwesterly
winds will become gusty Friday afternoon, especially across 
northeastern WY. 

&&

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

$$

DISCUSSION/KEY MESSAGES...Johnson
AVIATION...Pojorlie