729
FXUS63 KUNR 291938
AFDUNR
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
138 PM MDT SAT MAR 29 2025
KEY MESSAGES
-SNOW WILL CONTINUE THROUGH AFTERNOON OVER SOUTHWEST THROUGH SOUTH
CENTRAL SD, TAPERING OFF THIS EVENING
-A SERIES OF DISTURBANCES WILL BRING CHANCES FOR RAIN/SNOW TO THE
REGION THROUGH MID WEEK
-TEMPERATURES TO REMAIN MAINLY BELOW SEASONAL NORMS THROUGH THE
WEEK.
DISCUSSION
(THIS EVENING THROUGH SATURDAY)
ISSUED AT 137 PM MDT SAT MAR 29 2025
EAST EXTENSION OF THE ASIAN UPPER JET HAS RESULTED IN UNSETTLED
FLOW OVER THE PAC, SUPPORTING A SERIES OF IMPULSES INTO THE
WESTERN CONUS. THIS PATTERN WILL CONTINUE THROUGH THE WEEK, WITH
SEVERAL ROUNDS OF PAC SYSTEMS INTO THE REGION. THE FIRST OF THESE
SYSTEMS CONTINUES TO BRING MODERATE TO HEAVY SNOW ACROSS SCENTRAL
SD, WITH SOME AREAS OF FREEZING RAIN STILL ONGOING ACROSS PORTIONS
OF MELLETTE, TODD, AND TRIPP COUNTIES. PRECIP SHOULD QUICKLY
TRANSITION TO SNOW THERE AS COLD AIR WRAPS INTO THE SYSTEM. RATHER
IMPRESSIVE COMMA SHAPED SYSTEM ON SATELLITE, WITH EVEN SOME
THUNDER POSSIBLE ACROSS FAR SOUTH CENTRAL SD. GIVEN UNSTABLE
PROFILES PER SLANTWISE CONVECTION, EXPECT THAT AREAS UNDER ANY
PERSISTENT BANDS (SE BENNETT, AND FAR WESTERN TODD/MELLETTE) COULD
SEE 4 TO 6 INCHES OF SNOW THIS AFTERNOON. PRECIP WILL TAPER OFF
MOST PLACES OVERNIGHT WITH WEAK SUBSIDENCE SPREADING OVER MUCH OF
THE REGION, ALTHOUGH A FEW SNOW SHOWERS CANNOT BE RULED OUT. THE
NEXT SYSTEM WILL PUSH INTO THE REGION SUNDAY, WITH SNOW DEVELOPING
ACROSS NORTHEAST WY AND SPREADING INTO FAR WESTERN SD. AN INCH OR
2 TWO WILL BE POSSIBLE THERE, WITH UP TO 3 TO 4 INCHES IN THE
VERY HIGH ELEVATIONS OF THE BH. SNOW WILL LAST THROUGH MUCH OF THE
DAY, TAPERING OFF IN THE EVENING. RETURN FLOW WILL DEVELOP MONDAY
AHEAD OF THE NEXT STRONGER WAVE THAT WILL PUSH INTO THE ROCKIES.
WEAK IMPULSE WILL TRAVERSE THE FLOW AHEAD OF THIS SYSTEM WITH
STEEP LAPSE RATES AND WILL SUPPORT SCATTERED RAIN OR SNOW SHOWERS
OVER THE WESTERN THIRD. THIS AREA OF LIFT WILL SUPPORT SLIGHTLY
BETTER CHANCES FOR RAIN OR SNOW ON THE SD PLAINS MONDAY NIGHT
WHERE POS THETA-E ADV WILL ENSUE. ANOTHER STRONGER WAVE WILL PUSH
OUT OF THE ROCKIES WED AND SUPPORT A GOOD CHANCE OF RAIN AND SNOW
OVER THE REGION. SNOW AMOUNTS WILL HINGE ON THERMAL FIELDS,
STRENGTH OF LIFT, AND THE TIME PRECIP FALLS (DAY VS NIGHT). AFTER
WED, THINGS DRY OUT WITH JUST SOME CHANCES FOR SHOWERS AT TIMES AS
SEMI-UNSETTLED WESTERLY FLOW CONTINUES. TEMPS WILL ALSO MODERATE
SOME BY THE END OF THE WEEK, BUT STILL REMAIN AROUND SEASONAL
NORMS.
AVIATION
(FOR THE 18Z TAFS THROUGH 18Z SUNDAY)
ISSUED AT 1045 AM MDT SAT MAR 29 2025
MVFR TO LIFR CONDITIONS WILL CONTINUE ACROSS MUCH OF THE CWA
IN LOW CLOUDS, RAIN/SNOW/MIX. THESE CONDITIONS WILL PERSIST
THROUGH THE TAF PERIOD.
UNR WATCHES/WARNINGS/ADVISORIES
SD...WINTER WEATHER ADVISORY UNTIL 8 PM MDT /9 PM CDT/ THIS EVENING
FOR SDZ044-046-047-049-077.
WY...NONE.
DISCUSSION/KEY MESSAGES...JC
AVIATION...POJORLIE
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