790
FXUS63 KUNR 232307
AFDUNR
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
507 PM MDT MON MAR 23 2026
KEY MESSAGES
- DRY AND ABOVE AVERAGE TEMPERATURES MONDAY 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.
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 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 507 PM MDT MON MAR 23 2026
VFR CONDITIONS ARE EXPECTED THROUGH THE FORECAST PERIOD.
FIRE WEATHER
ISSUED AT 1238 PM MDT MON MAR 23 2026
ELEVATED FIRE WEATHER CONDITIONS THIS AFTERNOON
ACROSS THE AREA. WARMER AND DRIER TOMORROW, ALTHOUGH WINDS ARE
EXPECTED TO REMAIN BELOW CRITICAL THRESHOLDS. SHOULD A RFW BE
NEEDED TOMORROW, BEST CHANCE FOR OVERLAP OF LOW RH AND CRITICAL
WINDS WILL BE ACROSS FAR SOUTHERN CAMPBELL COUNTY (WY) AND FALL
RIVER (SD).
THE MAIN CONCERN WILL BE WEDNESDAY ACROSS NORTHEASTERN
WYOMING, THE BLACK HILLS (PARTICULARLY CENTRAL AND SOUTHERN BHS),
AND SOUTHWESTERN SOUTH DAKOTA WHERE RELATIVE HUMIDITY WILL FALL
INTO THE TEENS TO AROUND 20 PERCENT. 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. AS IT STANDS, HAVE ISSUED A FIRE WEATHER WATCH
WEDNESDAY FOR NORTHEASTERN WY, THE BLACK HILLS, AND SOUTHWESTERN
SD.
COLD FRONT WILL SHIFT WINDS NORTHWEST AFTER 2000-2200 WEDNESDAY
EVENING. OUTSIDE OF SPOTTY LIGHT SHOWERS, THE FRONTAL PASSAGE IS
EXPECTED TO BE DRY. NORTHWEST WINDS 30 TO 40 MPH ARE EXPECTED
THURSDAY BEHIND THE FRONT WITH RH IN THE 20S AND 30S.
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.
DISCUSSION/KEY MESSAGES...SE
AVIATION...13
FIRE WEATHER...SE
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