933
FXUS63 KABR 032128
AFDABR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ABERDEEN SD
328 PM CST MON FEB 3 2025
KEY MESSAGES
- A WEAK SYSTEM LATE WEDNESDAY WILL MAINLY BRING MOISTURE TO THE
FAR NORTHEAST OF SOUTH DAKOTA/WESTERN MN WITH ABOUT A 50/50
CHANCE FOR UP TO AN INCH OF SNOWFALL.
- A STRONGER SYSTEM IS SLATED FOR LATE IN THE WEEK WITH HIGHER
ACCUMULATING SNOW POTENTIAL. DETAILS TO BE REFINED OVER NEXT FEW
DAYS.
SHORT TERM /THIS EVENING THROUGH TUESDAY NIGHT/
ISSUED AT 328 PM CST MON FEB 3 2025
STILL SOME LINGERING LIGHT SNOW ACROSS THE EASTERN CWA THIS
AFTERNOON, BUT TRENDS ARE FOR THIS TO BE GRADUALLY ENDING OVER THE
NEXT FEW HOURS. POP GRIDS REFLECT THIS UP THROUGH 00Z. DEPENDING ON
THE SPEED OF THE EXITING LINGERING BATCH OF LIGHT SNOW, FLURRIES MAY
NEED TO BE ADDED TO THE FAR EASTERN CWA FOR A COUPLE HOURS THIS
EVENING. OTHERWISE, MODELS SUGGEST MID AND HIGH LEVEL CLOUDS MOVING
OVER THE REGION TONIGHT AS THE LOWER LEVEL CLOUDS TRY TO DISSIPATE
FROM WEST TO EAST. WINDS WILL ALSO GO LIGHTER THIS EVENING, AND
WHILE NOT A TRUE RADIATIONAL COOLING NIGHT, THE FRESH FEW INCHES OF
SNOW OVER THE NORTHERN CWA, ALONG WITH THE BITTERLY COLD AIR MASS IN
PLACE SHOULD ALLOW TEMPS TO DROP INTO THE SINGLE DIGITS BELOW ZERO
FOR MANY LOCATIONS. WE ARE SEEING ANOTHER AREA OF LIGHT SNOW OVER
WESTERN SD, WHICH MAY AFFECT FAR WESTERN PORTIONS OF THE CWA
TONIGHT. ONLY HAVE SLIGHT CHANCE (20%) POPS IN THE FORECAST FOR THIS
AS MEASURABLE SNOW MAY BE RATHER HARD TO COME BY.
ON TUESDAY, THE SURFACE RIDGE AXIS WILL SHIFT EAST INTO MN, ALLOWING
FOR EASTERLY WINDS TO DEVELOP DURING THE DAY. THE RATHER COLD AIR
MASS REMAINS OVERHEAD AS 925MB TEMPS STAY IN THE -15C TO -20C RANGE
ACROSS THE CWA. HIGHS IN THE SINGLE DIGITS AND TEENS WILL BE ALL
THAT CAN BE REACHED ACROSS THE AREA.
LONG TERM /WEDNESDAY THROUGH MONDAY/
ISSUED AT 328 PM CST MON FEB 3 2025
A MORE ZONAL TYPE PATTERN HAS/WILL TAKE OVER FOR THE EXTENDED, WITH
GENERALLY SLIGHTLY STRONGER SYSTEMS PASSING THROUGH THE REGION (IN
COMPARISON TO THE PREVIOUS PATTERN) WITH THE FOCUS ON WAVES THURSDAY
AND SATURDAY. THE ARCTIC BOUNDARY WILL ALSO REMAIN A PLAYER IN THE
FORECAST, SITUATED MAINLY SOUTH OF THE CWA/BETWEEN NEBRASKA AND
SOUTHWEST SOUTH DAKOTA, MEANING WE'LL REMAIN ENSCONCED WITHIN THE
COLDER AIRMASS FOR THE NEXT WEEK.
AT THE SURFACE WILL START WITH A LOW OVER THE CENTRAL ROCKIES, WITH
SOUTHEASTERLY LOW LEVEL FLOW OFF OF HIGH PRESSURE ACROSS THE GREAT
LAKES. INITIALLY THIS PRESENTS WITH NEUTRAL THERMAL ADVECTION,
HOWEVER AS WEDNESDAY ROLLS ON, WE SEE WARM ADVECTION IN THE MID
LEVELS TAKING SHAPE IN WESTERN SOUTH DAKOTA. THAT ROLLS EAST AHEAD
OF THE NEXT WAVE, WITH A WARM FRONT/TIGHT TEMPERATURE GRADIENT
ACROSS THE STATE. THIS ALSO SHOWS UP AS ONE OF THE MOST PRONOUNCED
MID LEVEL INVERSIONS WE'VE SEEN THIS WINTER. WEAK ASCENT WITH THE
WARM FRONT COULD GENERATE SOME LIGHT PRECIPITATION, BUT NAM PROFILES
DEPICT A DRY SUBCLOUD LAYER, WITH A SHALLOW SATURATED LAYER, ALL
BELOW FREEZING BUT WARMER IN COMPARISON TO THE DENDRITIC GROWTH
ZONE. NAM DOES EVENTUALLY, BRIEFLY SATURATE, UP AROUND 500MB/12KFT
AND PROVIDE SOME SEEDER-FEEDER WITH A DEEP SATURATED PROFILE BUT
THEN WE RAPIDLY LOSE ICE AND THE PROFILE DRIES. EVEN IN THE FAR
NORTHEAST, WHERE NBM MOISTURE IS THE HIGHEST, THIS IS STILL
RELEGATED TO ONLY AN HOUR OR TWO OF POTENTIAL SNOWFALL OUT OF THE
NAN PROFILES, BEFORE THEY COOL/DRY TO THE POINT OF FREEZING DRIZZLE
AND THEN BACK TO FLURRIES AS THE LOWER PORTION OF THE PROFILE COOLS
ENOUGH TO BACK INTO THE DENDRITIC GROWTH ZONE THURSDAY MORNING. NBM
PROBABILITIES OF 0.1 INCHES MOISTURE IS ONLY ABOUT 50% UP AROUND
SISSETON/WHEATON.
HIGH PRESSURE FOLLOWS ON THE BACKSIDE, AT 1025-1030MB CENTERED OVER
THE NORTHER ROCKIES WITH A TIGHT GRADIENT INITIALLY (ABOUT 10MB E-W
ACROSS THE STATE). THAT HIGH EXTENDS OUT OVERHEAD FOR
THURSDAY/THURSDAY NIGHT. COLD ADVECTION THURSDAY WILL ALSO ASSIST IN
ACCELERATING WINDS. NBM WINDS ARE ON THE ORDER OF UPPER TEENS TO UPPER
20S WHICH IS A LITTLE LOW IN COMPARISON TO NAM/GFS MIXED WINDS AND
SOMETHING WE WILL NEED TO GET INTO GREATER DETAIL AS WE GET INTO MID-
WEEK. THUS, WITH THE FRESH SNOW COVER, FEEL CONFIDENT THAT WE WILL
NEED TO KEEP THE MENTION OF BLOWING/DRIFTING SNOW.
THE CORE OF COLDEST AIR PRETTY MUCH GOES ACROSS NORTH DAKOTA AND WE
MAINTAIN A THERMAL GRADIENT ACROSS SOUTH DAKOTA INTO FRIDAY. THAT
THERMAL GRADIENT WEAKENS BRIEFLY AS THE HIGH HEADS EAST, BUT
REDEVELOPS AHEAD OF THE NEXT SYSTEM SO AGAIN, THE WARM FRONT
DEVELOPS OVERHEAD. MODEL QPF IS MORE CENTERED ACROSS SOUTH DAKOTA
THIS TIME, WITH THE GFS/CANADIAN/EC IN FAIRLY GOOD AGREEMENT FOR 120
HOURS. NBM PROBS POINT TO MAINLY A SNOW EVENT, AND THAT MATCHES WELL
WITH DETERMINISTIC GFS 700MB TEMPERATURES AT -12 TO -18C...THOUGH IT
SHOULD BE NOTED A TIGHT THERMAL GRADIENT OVER SOUTHERN SOUTH DAKOTA,
SO ANY FUTURE SHIFTS IN THE POSTILION OF THE WARM FRONT COULD
ULTIMATELY IMPACT THE RAIN-SNOW LINE.
AS FOR TEMPERATURES, WITH THE THERMAL GRADIENT/WARM AND COLD
ADVECTION CONSTANTLY IN PLAY ACROSS THE REGION, THERE IS LOWER
CONFIDENCE IN FORECAST HIGHS/LOWS. NBM 25TH/75TH PROBABILITIES FOR
HIGHS SHOW ABOUT A 10 DEGREE SPREAD THURSDAY THOUGH THE WEEKEND.
OVERALL THE TREND IS FOR AT OR BELOW NORMAL TEMPERATURES FOR MOST OF
THE TIME PERIOD. SEEMS REASONABLE AS WE CONTINUE TO SEE POTENTIAL
FOR INCREASING THE SNOWPACK.
AVIATION /18Z TAFS THROUGH 18Z TUESDAY/
ISSUED AT 1132 AM CST MON FEB 3 2025
TERMINALS KABR,KATY,KPIR,KMBG
MVFR CONDITIONS WILL GIVE WAY TO VFR CONDITIONS THROUGH THE
AFTERNOON TODAY. THIS IS DUE TO THE LOW LEVEL MOISTURE ASSOCIATED
WITH THE SYSTEM THAT BROUGHT THE SNOW LAST NIGHT MOVING EAST AND
OUT OF THE AREA. CONFIDENCE IS A LITTLE LOWER ON THE TIMING OF THE
END OF THE SNOW/MVFR CONDITIONS, AS MODELS HAVE BEEN STRUGGLING
WITH THE LINGERING OF THE SNOW, BUT SEEMS CONSISTENT TO BE OUT OF
THE CENTRAL SITES OVER THE NEXT COUPLE OF HOURS AND HANGING ON THE
LONGEST AT KATY. THE REST OF THE FORECAST LOOKS TO BE VFR, WITH
JUST OCCASIONAL MID LEVEL CLOUDS MOVING OVER.
ABR WATCHES/WARNINGS/ADVISORIES
SD...NONE.
MN...NONE.
SHORT TERM...TMT
LONG TERM...CONNELLY
AVIATION...SRF
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