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530
FXUS63 KUNR 191903
AFDUNR

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
103 PM MDT Thu Sep 19 2024

.KEY MESSAGES...

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-Warm Friday with much cooler and breezy conditions this weekend

-Elevated fire weather conditions continue through Saturday with
 critical conditions possible in southwest areas Friday

-Mainly dry conditions the next several days
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&&

.DISCUSSION...
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(This Evening Through Thursday)
Issued at 100 PM MDT Thu Sep 19 2024

Mean western NOAM trough will progress east through the weekend,
bringing a warm day Friday, with cool and breezy conds this
weekend. Southern Canadian upper low will exit the region tonight,
with sfc high pressure spreading into the region. This will
support light winds and clear skies as WAA ensues over western
areas. Lee-side trough will get kicked east Friday as the mean
upper trough shifts east. Expect much warmer conds Friday as the
thermal ridge shifts over the region with breezy conds over the
far SW where deeply mixed WSW flow will become established. Upper
trough will shift east Friday night, supporting a cold front into
the region. Pressure rises and CAA associated with the front will
support breezy conds, with adv level winds possible on the plains
east of the Black Hills. Temps will only top out in the 60s and
low 70s most places both Sat and Sun with lows in the 30s and 40s.
Some frost will be possible Sat night across the NW half, where
skies remain clear. Secondary impulse will skirt south of the
area, supporting a very small chance for showers near the NE
border Sat night into Sunday. The trend for this system has been
south. Upper ridge will slowly build back into the region next
week with above normal temps returning and mainly dry weather
continuing. There is an outside chance for a shower or two Monday
with a passing upper trough. However, moisture will be very
limited with this system.
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&&

.AVIATION...(For the 18Z TAFS Through 18Z Friday)
Issued At 1124 AM MDT Thu Sep 19 2024

VFR conditions are expected through the forecast period. Gusty
west-northwest winds will continue into this afternoon with the
strongest gusts (45-55kts) over northwest SD before diminishing
around 01Z.

&&

.FIRE WEATHER...
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Issued At 100 PM MDT Thu Sep 19 2024

Elevated fire weather conditions will continue through Saturday
across the region. On Friday, drier air returns with Min RHs in
the teens to mid 20s. Near critical conditions will likely develop
over parts of northeast WY and far southwest SD where winds may
gust over 25 mph. Have issued a fire weather watch for this area.
On Saturday, gusty northwest winds will develop behind a cold
front, but RH`s will rise back into the 20 and 30s.
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&&

.UNR WATCHES/WARNINGS/ADVISORIES...
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SD...Wind Advisory until 3 PM MDT this afternoon for SDZ001-002-
     012>014-025-072-073-078.
     Fire Weather Watch from Friday afternoon through Friday evening
     for SDZ320>322-325-326.
WY...Fire Weather Watch from Friday afternoon through Friday evening
     for WYZ315-317.
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&&

$$

DISCUSSION/KEY MESSAGES...JC
AVIATION...Bunkers/Schultz
FIRE WEATHER...JC