058
FXUS63 KABR 041616 AAB
AFDABR
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE ABERDEEN SD
1016 AM CST TUE FEB 4 2025
KEY MESSAGES
- THERE IS A 50% CHANCE OF SNOW WEDNESDAY EVENING OVER FAR
NORTHEAST SD AND WEST CENTRAL MN. LESS THAN AN INCH OF SNOW IS
EXPECTED.
- OUR NEXT CHANCE OF PRECIPITATION WILL BE FRIDAY INTO SATURDAY,
WITH A 60% CHANCE OF SNOW. A WIDESPREAD 2-4 INCHES WITH LOCALLY
HIGHER AMOUNTS ARE POSSIBLE.
UPDATE
ISSUED AT 1009 AM CST TUE FEB 4 2025
HIGH PRESSURE REMAINS TO OUR NORTH WITH MID TO HIGH CLOUDS OVER
THE AREA. TEMPERATURES AS OF 10AM RANGE FROM AROUND ZERO TO 3
DEGREES, WARMEST OVER CENTRAL SD. ANOTHER COLD DAY TODAY WITH
HIGHS FROM 10 TO THE UPPER TEENS. FORECAST REMAINS ON TRACK AND NO
CHANGES MADE.
UPDATE ISSUED AT 515 AM CST TUE FEB 4 2025
SEE BELOW FOR AN AVIATION FORECAST DISCUSSION FOR THE 12Z TAFS.
SHORT TERM /TODAY THROUGH WEDNESDAY AFTERNOON/
ISSUED AT 329 AM CST TUE FEB 4 2025
AT 3 AM CST, A NEARLY 1040HPA SURFACE HIGH PRESSURE IS
SITUATED/CENTERED ON THE EASTERN DAKOTAS AND WESTERN MINNESOTA.
THERE ARE A LOT OF MID AND HIGH CLOUDS COVERING THE REGION (AN APPX
7000-9000FT CEILING OVER MUCH OF THIS CWA). DESPITE THE CLOUDINESS,
THE EXTENT OF COLDNESS OF THE AIR (925HPA TEMPERATURES APPX -18C
TO -20C OVER THE CWA RIGHT NOW) AND THE FRESH SNOWCOVER MAINLY
OVER THE NORTHERN THIRD OF THE CWA IS HELPING TO PUSH THE MERCURY
DOWN BELOW 0F NORTH OF A LINE FROM CLEAR LAKE TO ONIDA TO EAGLE
BUTTE. SOUTH OF THAT LINE, TEMPERATURES ARE STILL BETWEEN 0F AND
5F ABOVE. WINDS ARE GENERALLY OUT OF THE NORTH AT 5 TO 15 MPH.
THIS SURFACE HIGH PRESSURE (AND A BUILDING UPPER LEVEL RIDGE
OVERHEAD) SHOULD KEEP THE CWA DRY, BUT COLD TODAY, AS SURFACE WINDS
GRADUALLY BECOME EAST TO PERHAPS SOUTHEAST BY THE END OF THE DAY.
THE UPPER LEVEL RIDGE AXIS MOVES OVER THE REGION TONIGHT, SHIFTING
EAST OF THIS CWA HEADING INTO WEDNESDAY MORNING, AND ALLOWING FOR
SOME WEST-SOUTHWESTERLY FLOW ALOFT TO ENSUE DURING THE DAY ON
WEDNESDAY. THE SURFACE HIGH WILL HAVE MOVED WELL OFF TO THE
EAST/NORTH BY WEDNESDAY MORNING, ALLOWING FOR 15 TO 25 MPH
SOUTHEASTERLY WINDS TUESDAY NIGHT TO BECOME MORE SOUTH-SOUTHEASTERLY
AND PERHAPS EVEN INCREASING A BIT MORE TO SOMETHING CLOSER TO 20 TO
30 MPH WITH HIGHER GUSTS. AFTER TODAY, LOW/MID-LEVEL WAA GRADUALLY
PICKS UP STEAM TONIGHT INTO WEDNESDAY. A LOT OF HIGHS IN THE 20S AND
30S EXPECTED ON WEDNESDAY. ACROSS THE FAR SOUTHWESTERN FORECAST
ZONES, LOW LEVEL WARMING SUPPORTS THE POTENTIAL FOR HIGHS TO RUN UP
INTO THE 40S.
THE SHORT TERM FORECAST IS A DRY FORECAST, EXCEPT HEADING INTO
WEDNESDAY AFTERNOON. THIS MID-LEVEL (ABOVE 0C) WARM LAYER IS STILL
SHOWING UP IN THE NAM/GFS BUFKIT SOUNDINGS, WARMEST GENERALLY AT OR
NEAR 750HPA. BENEATH THAT, THE COLD DOME IN PLACE IS NOTABLE. THE
RAP MODEL IS LATCHING ON TO A LEAD MID-LEVEL SHORTWAVE TROFPA ON
WEDNESDAY OUT AHEAD OF THE LARGER UPPER LEVEL TROF PROGGED TO MOVE
ACROSS THE REGION AFTER THE WEDNESDAY DAY PERIOD. IF THIS LEAD
SHORTWAVE TREND IS LEGIT, THERE COULD BE A PERIOD OF TIME (ATTACHED
TO THE POSITIVE VORTICITY ADVECTION) WHEN PRECIPITATION IS TRYING TO
DEVELOP ALOFT (FROZEN HYDROMETEORS), POTENTIALLY FALL THROUGH THIS
WARM LAYER (PARTIAL TO FULL MELTING INTO LIQUID HYDROMETEORS) AND
THEN RE-FREEZE WITHIN THIS DEEP COLD LAYER (SNOW AND SLEET). A LOT
OF IF'S. AS THE PREVIOUS FORECASTER MENTIONED, THE COLUMN IS NOT
FAVORABLY SATURATED FOR ALL THIS TO HAPPEN (LIKELY
EVAPORATION/SUBLIMATION SOMEWHERE BETWEEN 300HPA AND THE SURFACE),
AND EVEN IF IT DOES END UP BECOMING SUPPORTIVE OF PRECIP REACHING
THE GROUND, IF WOULD LIKELY ONLY BE A ONE OR TWO HOUR WINDOW OF TIME
WHEN PRECIP POTENTIAL WOULD EXIST. THE ENSEMBLE P-TYPE APPROACH THIS
MORNING DID NOT YIELD AS MUCH SLEET MENTION IN THE WX GRIDS AS
DESIRED. BUT, THE POTENTIAL IS CERTAINLY THERE, ALONG WITH SNOW
POTENTIAL. PERHAPS OVER THE NEXT COUPLE OF MODEL RUNS, SLEET MIGHT
FIND ITS WAY INTO THE FORECAST MORESO THAN IT CURRENTLY IS. THE
OTHER THING BEING WATCHED IS WHETHER OR NOT THERE IS ENOUGH TIME FOR
THE GULF TO OPEN UP A ROUTE FOR LOW LEVEL MOISTURE (COLD DOME LOW
STRATUS?) TO WORK UP INTO THE EASTERN FORECAST ZONES.
LONG TERM /WEDNESDAY EVENING THROUGH MONDAY/
ISSUED AT 329 AM CST TUE FEB 4 2025
SNOW WILL END THURSDAY MORNING AS THE SHORTWAVE TROUGH RESPONSIBLE
FOR THE PRECIPITATION WILL PROGRESS EASTWARD AND MOVE THE ABR
FORECAST AREA OUT OF THE LEFT EXIT REGION. A ZONAL TO POSSIBLY
SLIGHT RIDGING PATTERN WILL TAKE HOLD AND KEEP HIGH TEMPERATURES IN
THE UPPER TEENS TO LOW 20S (5-10 DEGREES BELOW NORMAL).
CHANCES FOR SNOW WILL RETURN ON FRIDAY NIGHT INTO SATURDAY WITH
ANOTHER SHORTWAVE DISTURBANCE MOVING IN. SPREAD IN THE ENSEMBLES HAS
COME DOWN ONLY SLIGHTLY IN THE PAST 24 HOURS, NOW TOPPING OUT AT A
25TH-75TH SPREAD OF 0-5 INCHES IN THE NBM. 24 HOUR PRECIPITATION
ENDING AT 6 PM SATURDAY SUGGEST VALUES UP TO 0.4" IN THE 75TH
PERCENTILE OVER PORTIONS OF CENTRAL SOUTH DAKOTA. THIS APPEARS TO BE
ABOVE PWAT VALUES, SO SOMEWHERE CLOSER TO THE 50TH PERCENTILE (0.15-
0.2") WOULD SEEM TO BE MORE REASONABLE AT THIS TIME. WITH SLRS
FORECASTED TO BE AROUND 16-17:1, THIS WOULD PUT SNOW TOTALS IN THE 2-
4" RANGE THROUGH THE EVENT.
BEYOND SATURDAY, A COLD AIR ADVECTION REGIME WILL SET UP DUE TO A
LONGWAVE TROUGH SETTING UP OVER THE CONUS, PUTTING THE ABR FORECAST
AREA ON THE BACK SIDE AND ALLOWING THE COLDER AIR TO DROP SOUTH.
HIGHS WILL BE IN THE SINGLE DIGITS TO START NEXT WEEK, WHICH IS ~15-
20 DEGREES BELOW NORMAL FOR THIS TIME OF YEAR. WIND GUSTS WILL
APPROACH 20 KNOTS ACROSS THE FORECAST AREA SUNDAY AND MONDAY NIGHTS,
WHICH WILL PUSH WIND CHILLS CLOSE TO COLD WEATHER ADVISORY CRITERIA.
ENSEMBLE PROBABILITIES OF HITTING CRITERIA IS 20-40% NEXT MONDAY-
WEDNESDAY MORNINGS.
AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/
ISSUED AT 515 AM CST TUE FEB 4 2025
TERMINALS KABR,KATY,KPIR,KMBG
VFR CONDITIONS ARE EXPECTED OVER THE NEXT 24 HOURS. KPIR/KMBG WILL
EVENTUALLY DEVELOP 15 TO 25 KNOT GUSTS FROM THE EAST-SOUTHEAST.
ABR WATCHES/WARNINGS/ADVISORIES
SD...NONE.
MN...NONE.
UPDATE...MMM
SHORT TERM...DORN
LONG TERM...BC
AVIATION...DORN
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