133
FXUS63 KUNR 110725
AFDUNR

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
125 AM MDT Thu Jul 11 2024

.KEY MESSAGES...

- Becoming hotter with heat headlines possible through the weekend
- Limited precipitation chances, but marginal risk isolated severe
  thunderstorms both this afternoon and again Friday afternoon
- Elevated fire weather conditions

&&

.DISCUSSION...(Today Through Wednesday)
Issued at 106 AM MDT Thu Jul 11 2024

Water vapor shows upper high over the Desert SW with flat ridge
through the Pac NW/Northern Rockies and northwest flow across the
Northern Plains. At the surface, high covers the eastern Dakotas
with advancing lee trof over eastern MT and northern/eastern WY.

Hot temperatures will continue to spread into the Plains today as
western CONUS ridge nudges east. Highs will reach well into the
90s across all but far south-central SD (and the Black Hills),
although lower dewpoints should keep apparent temps a touch
cooler. Some late day storms possible, especially around the Black
Hills and adjacent plains, and given high storm bases there is
some threat for severe winds gusts. Additional isolated activity
is possible tonight given weak wave traversing the upper ridge.

Even hotter temps expected Friday with some potential for a heat
advisory, especially on the SD plains where dewpoints will be high
enough to raise apparent temps to near 100F. Additional isolated
storm activity possible late in the day and again, primarily
around the Black Hills and northeast WY into northwest SD, with
some threat for severe wind gusts once again.

Saturday into Sunday will likely be the hottest as thermal ridge
peaks ahead of an approaching upper trof, and heat advisories may
need to be issued or continued. Late day thunderstorm chances,
albeit low, will continue.

Upper ridge flattens late Sunday into Monday as upper trof dives
southeast across south-central Canada and drives a cold front
through the Northern Plains. This will well up a pattern change
through at least the middle of next week with more unsettled and
cooler weather expected.

&&

.AVIATION...(For the 06Z TAFS Through 06Z Thursday Night)
Issued At 1030 PM MDT Wed Jul 10 2024

Isolated thunderstorms are possible overnight across parts of
northeastern Wyoming and the Black Hills. Additional isolated
thunderstorms are possible Thursday afternoon and evening over
much of the area. Locally gusty winds possible with the stronger
storms Thursday afternoon and evening.

&&

.FIRE WEATHER...
Issued At 106 AM MDT Thu Jul 11 2024

Elevated fire weather conditions are expected through the
weekend as hotter and drier weather moves in. Minimum afternoon
relative humidities will dip in the teens and 20s with the lowest
readings over northeastern WY/far western SD (10-15% likely).
However, winds are not expected to be particular strong. Nighttime
relative humidity recovery will be poor over the higher terrain
of northeastern WY/Black Hills. Isolated thunderstorm activity
will be possible most days, and given the expected high
thunderstorm bases, precipitation with these storms may be
minimal.

&&

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

$$

DISCUSSION/KEY MESSAGES...Johnson
AVIATION...7
FIRE WEATHER...Johnson