199
FXUS63 KUNR 241201
AFDUNR
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
601 AM MDT TUE MAR 24 2026
KEY MESSAGES
- DRY AND ABOVE AVERAGE TEMPERATURES THROUGH WEDNESDAY WITH
ELEVATED TO NEAR-CRITICAL FIRE WEATHER CONDITIONS; WARMEST AND
DRIEST WEDNESDAY AHEAD OF A COLD FRONT.
- COLD FRONT TO BRING MORE SEASONABLE TEMPERATURES THURSDAY ALONG
WITH SPOTTY LIGHT SHOWERS, ALTHOUGH MOST AREAS WILL REMAIN DRY.
- TRENDING MILD AND DRY AGAIN FRIDAY INTO NEXT WEEKEND WITH
ELEVATED FIRE WEATHER CONDITIONS LIKELY.
UPDATE
ISSUED AT 956 PM MDT MON MAR 23 2026
SURFACE ANALYSIS SHOWS TEMPERATURES DROPPING THIS EVENING INTO THE
40S, ESPECIALLY BEHIND A WEAK COOL FRONT WHICH IS APPROACHING THE
BLACK HILLS AND IS PROGGED TO STALL NEAR I-90 TONIGHT. LOW AMPLITUDE
RIDGING ALOFT CENTERED OVER THE PAC NW WILL CONTINUE EASTWARD OVER
THE NEXT COUPLE OF DAYS, WITH THE MAIN AXIS REACHING THE NORTHERN
HIGH PLAINS BY WEDNESDAY. WARM AIR ADVECTION WILL REDEVELOP ACROSS
NE WY/SW SD TUESDAY MORNING. FORECAST LOOKS ON TRACK WITH WARMING
TEMPS BOTH TUESDAY AND WEDNESDAY BEFORE THE NEXT COLD FRONT COOLS
THINGS BACK CLOSER TO NEAR CLIMATOLOGY (STILL SLIGHTLY WARMER,
ACTUALLY). MAIN FOCUS OF THE FORECAST ARE THE FIRE WEATHER CONCERNS,
WHICH WILL BE ADDRESSED BELOW.
DISCUSSION
(THIS EVENING THROUGH MONDAY)
ISSUED AT 1238 PM MDT MON MAR 23 2026
LARGELY ZONAL FLOW AS UPPER RIDGING BUILDS OVER THE WESTERN HALF
OF THE COUNTRY. SURFACE HIGH PRESSURE HAS SETTLED INTO THE
UPPER/MIDDLE MISSISSIPPI VALLEY. WEST-SOUTHWESTERN MID-LEVEL FLOW
IS ADVECTING WARMER AIR INTO THE REGION, ALTHOUGH LINGERING LOW
CLOUDS ACROSS SOUTH-CENTRAL SD ARE SLOWING HEATING THIS AFTERNOON.
UPPER LEVEL HIGH OVER THE SOUTHWEST US WILL DOMINATE THE WEATHER
THROUGH AT LEAST MID-WEEK AS UPPER RIDGING PERSISTS. WARMEST DAY
WEDNESDAY WITH WIDESPREAD 70S AND LOWER TO MID 80S (MAINLY ALONG AND
SOUTH OF I-90). ELEVATED FIRE WEATHER CONDITIONS THIS AFTERNOON AND
AGAIN TUESDAY, ALTHOUGH CRITICAL CONDITIONS ARE NOT EXPECTED.
CRITICAL CONDITIONS ARE POSSIBLE WEDNESDAY, ESPECIALLY ACROSS
NORTHEASTERN WYOMING INTO THE BLACK HILLS AND SOUTHWESTERN SOUTH
DAKOTA, WHERE A FIRE WEATHER WATCH IS NOW IN EFFECT. LOWER
CONFIDENCE IN WINDS REACHING CRITICAL THRESHOLDS ACROSS WESTERN
SOUTH DAKOTA. SOME FORECAST SOUNDINGS SHOW SLIGHTLY LOWER MIXING
HEIGHTS, HOWEVER, IF WE ARE ABLE TO MIX ABOVE 700-600MB INTO THE
HIGHER MOMENTUM AIR ALOFT, GUSTS > 25 MPH WILL BE MORE LIKELY.
A COLD FRONT WILL SURGE THROUGH THE FORECAST AREA LATE WEDNESDAY
EVENING THROUGH THURSDAY MORNING, SHIFTING WINDS NORTHWEST AND
INCREASING BEHIND THE FRONT. SPOTTY LIGHT SHOWERS ARE POSSIBLE
BEHIND THE FRONT ACROSS NORTHWESTERN SOUTH DAKOTA, BUT PRECIPITATION
AMOUNTS WILL BE LIMITED. SLIGHTLY ABOVE SEASONABLE TEMPERATURES
THURSDAY AND FRIDAY BEFORE WARMTH RETURNS ALONG WITH ELEVATED TO
NEAR-CRITICAL FIRE WEATHER CONDITIONS INTO THE WEEKEND.
AVIATION
(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 600 AM MDT TUE MAR 24 2026
VFR CONDITIONS ARE EXPECTED THROUGH THE FORECAST PERIOD.
FIRE WEATHER
ISSUED AT 956 PM MDT MON MAR 23 2026
ELEVATED FIRE WEATHER CONDITIONS WILL CONTINUE TUESDAY AFTERNOON
ACROSS PORTIONS NORTHEAST WY THROUGH FAR SW SD. CONDITIONS FALL
SHORT OF NEARING CRITICAL THRESHOLDS; HOWEVER, WITH MIN RH
REACHING 18-25%, MONITORING IS STILL PRUDENT. WINDS WILL REMAIN
RELATIVELY LIGHT THROUGH TUESDAY AFTERNOON, WITH OCCASIONAL GUSTS
TO 10-20MPH.
THE MAIN CONCERN CONTINUES TO BE WEDNESDAY ACROSS NORTHEASTERN
WYOMING, THE BLACK HILLS (PARTICULARLY CENTRAL AND SOUTHERN BHS),
AND SOUTHWESTERN SOUTH DAKOTA WHERE RELATIVE HUMIDITY AT OR BELOW
15% WILL BE POSSIBLE. HIGHS WILL WARM INTO THE 70S TO MID 80S WITH
GUSTY WEST WINDS ACROSS THESE AREAS (GUSTS 25 TO 40 MPH) WITH
LIGHTER WINDS ON THE WESTERN SD PLAINS. THERE IS POTENTIAL FOR
GREATER MIXING ON THE PLAINS, WHICH WOULD RESULT IN A BETTER CHANCE
OF CRITICAL WINDS; WILL CONTINUE TO MONITOR FOR THAT POTENTIAL.FIRE
WEATHER WATCH CONTINUES WITH NO CHANGES.
A COLD FRONT WEDNESDAY EVENING WILL BRING COOLER TEMPS THURSDAY, MIN
RH OF 30-40%, AND NW WINDS GUSTING TO 30-40 MPH. OUTSIDE OF SPOTTY
LIGHT SHOWERS, THE FRONTAL PASSAGE IS EXPECTED TO BE DRY.
UNR WATCHES/WARNINGS/ADVISORIES
SD...FIRE WEATHER WATCH FROM WEDNESDAY MORNING THROUGH WEDNESDAY
EVENING FOR SDZ319>326-332-333.
WY...FIRE WEATHER WATCH FROM WEDNESDAY MORNING THROUGH WEDNESDAY
EVENING FOR WYZ314>318.
UPDATE...13
DISCUSSION/KEY MESSAGES...SE
AVIATION...WONG
FIRE WEATHER...13
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