239
FXUS63 KUNR 161012
AFDUNR

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
412 AM MDT Tue Jul 16 2024

.KEY MESSAGES...

- Normal summer conditions continue

&&

.DISCUSSION...(Today Through Monday)
Issued at 142 AM MDT Tue Jul 16 2024

Current surface map places weak low across eastern Montana.
Shortwave embedded in northwest flow is tracking across eastern
Montana with weak theta-e advection bringing isolated/scattered
convection across eastern Montana into central South Dakota.
Current activity will shift eastward by daybreak. Focus will turn
to thunderstorms this afternoon. Surface low drops through south
central South Dakota into Nebraska this afternoon. With steep mid
level lapse rates, MLCAPE of 1500-2000J/KG expected across south
central South Dakota. Sufficient shear to support isolated severe
threat. Timing of shortwave suggest best thunderstorm
coverage/severe threat will be south of the forecast area.

Northwest flow aloft continues across the through the remainder
of the week as persistent upper level ridge remains across the
Intermountain west. Surface high slips through the eastern
Dakotas on Wednesday/Thursday with drier conditions for much of
the area. Narrow axis of buoyancy will favor some isolated
thunderstorm activity across northeastern Wyoming/western South
Dakota Wednesday and Thursday. The chance for thunderstorms
continue into the weekend as several impulses rotate over the
ridge and drop through the plains. Highs will mainly be in the 80s
through the forecast period with 70s in the Black Hills. Thursday
and Friday will be the warmest days with some locations on the
plains reaching the lower 90s.

&&

.AVIATION...(For the 12Z TAFS Through 12Z Wednesday Morning)
Issued At 409 AM MDT Tue Jul 16 2024

VFR conditions are expected through the forecast period. Isolated
showers and storms will develop across northwestern SD this
morning with LCL MVFR conditions near any storms. Isolated storms
may develop this afternoon, especially across the Black Hills
into south central SD. Some storms over south central SD may be
strong to severe and capable of hail and gusty, erratic winds.

&&

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

$$

DISCUSSION/KEY MESSAGES...7
AVIATION...Wong