225
FXUS63 KABR 232346 AAA
AFDABR
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE ABERDEEN SD
646 PM CDT WED APR 23 2025
KEY MESSAGES
- RAINFALL CHANCES INCREASE TONIGHT AND THURSDAY. PORTIONS OF
CENTRAL SOUTH DAKOTA AND EAST CENTRAL SOUTH DAKOTA MAY SEE
AMOUNTS IN EXCESS OF ONE QUARTER OF AN INCH.
- THE NEXT CHANCE OF RAIN (50 TO 80%) WILL BE FOR THE SECOND
HALF OF THE UPCOMING WEEKEND INTO EARLY NEXT WEEK. THERE IS A
15% CHANCE FOR SEVERE STORMS EAST OF THE JAMES RIVER MONDAY.
UPDATE
ISSUED AT 637 PM CDT WED APR 23 2025
SEE BELOW FOR AN AVIATION FORECAST DISCUSSION FOR THE 00Z TAFS.
SHORT TERM /THIS EVENING THROUGH THURSDAY NIGHT/
ISSUED AT 321 PM CDT WED APR 23 2025
WEAK UPPER LEVEL RIDGING CURRENTLY OVER THE REGION WILL GRADUALLY
GET PUSHED EAST LATE TONIGHT INTO THURSDAY MORNING AS SHORTWAVE
ENERGY TRACKS ACROSS WESTERN SOUTH DAKOTA NORTHEASTWARD OVER NORTH
DAKOTA. A MORE SOUTHWESTERLY FLOW WILL THEN BE IN PLACE THURSDAY
AFTERNOON INTO THURSDAY NIGHT, WITH PERIODS OF WEAK ENERGY RIDING UP
AND ACROSS THE CWA.
AT THE SURFACE, HIGH PRESSURE CURRENTLY EXTENDS FROM SOUTH CENTRAL
CANADA TO SOUTHERN SOUTH DAKOTA. THE HIGH WILL GET PUSHED BACK TO
THE NORTHEAST TONIGHT AS LOW PRESSURE SLIDES ACROSS THE CENTRAL
ROCKIES. A BOUNDARY WILL SET UP SOUTH OF THE REGION, BUT RAIN SHOWER
ACTIVITY WILL BE AIDED BY THE UPPER LEVEL SHORTWAVE ENERGY AND LOOKS
TO REACH AS FAR NORTH AS SOUTHERN NORTH DAKOTA LATE TONIGHT THROUGH
THE DAY THURSDAY. CAMS ARE STILL A BIT UNCERTAIN WHERE THE EXACT
FOCUS FOR HIGHER PRECIPITATION AMOUNTS WILL BE, BUT THE HIGHEST
CURRENT PROBABILITIES (30 TO 40 PERCENT) OF ONE QUARTER INCH OR MORE
ARE ACROSS PORTIONS OF CENTRAL SOUTH DAKOTA AND ACROSS EAST CENTRAL
SOUTH DAKOTA. DUE TO COOLER AIR IN PLACE, INSTABILITY IS MINIMAL AT
BEST, SO NOT ANTICIPATING ANY THUNDERSTORM ACTIVITY. THE
PRECIPITATION LOOKS TO COME TO AN END THURSDAY EVENING AS HIGH
PRESSURE DROPS BACK IN OVER THE NORTHERN AND CENTRAL PLAINS.
LOW TEMPERATURES TONIGHT WILL BE IN THE MID 30S TO LOWER 40S. HIGH
TEMPERATURES ON THURSDAY WILL BE IN THE UPPER 40S TO UPPER 50S. LOWS
THURSDAY NIGHT WILL BE IN THE MID 30S TO LOWER 40S.
LONG TERM /FRIDAY THROUGH WEDNESDAY/
ISSUED AT 321 PM CDT WED APR 23 2025
THE FOCUS IN THIS PERIOD WILL REVOLVE AROUND A WELL ORGANIZED STORM
SYSTEM THAT IS PROGGED TO TRACK THROUGH THE REGION THE SECOND HALF
OF THE WEEKEND INTO EARLY NEXT WEEK. OUR FORECAST AREA STANDS TO
PICK UP ON SOME DECENT RAINFALL AMOUNTS AND PERHAPS THE FIRST BOUTS
OF SEVERE WEATHER FOR THE SPRING SEASON. PRIOR TO THAT, THIS PERIOD
WILL BEGIN RELATIVELY TRANQUIL AS SFC HIGH PRESSURE RESIDES TO THE
NORTH AND NORTHEAST OF THE AREA ON FRIDAY. THIS WILL GIVE OUR AREA A
DRY AND MILD DAY OVERALL WITH NORTHERLY LOW LEVEL FLOW KEEPING 850MB
TEMPERATURES IN THE SINGLE DIGITS ABOVE ZERO C AND DAYTIME HIGHS
RIGHT AROUND NORMAL IN THE LOW TO MID 60S. HIGH PRESSURE SHIFTS EAST
AND WE PICK UP ON RETURN FLOW OUT OF THE SOUTH FRIDAY NIGHT THROUGH
SATURDAY. THE PRESSURE GRADIENT TIGHTENS ON SATURDAY LEADING TO
GUSTY SOUTHERLY WINDS OF 30-40 MPH. UPPER RIDGING BUILDS ACROSS THE
NORTHERN PLAINS LEADING TO A WARMER AIR MASS RETURNING TO THE REGION
SATURDAY INTO SUNDAY. 850MB TEMPS CLIMB FROM +5C TO +10C ON SATURDAY
TO ABOUT +10C TO NEAR +20C ON SUNDAY. IN ADDITION TO THE WARMER AIR,
LOW LEVEL MOISTURE WILL BE INCREASING THIS WEEKEND. DEW POINT
TEMPERATURES GO FROM 30S TO LOW 40S ON SATURDAY TO ABOUT 50 TO 55
DEGREES ON SUNDAY. ALL THESE CHANGES ARE SETTING THE STAGE FOR
ACTIVE WEATHER TO RETURN ON SUNDAY AND PERSIST THROUGH TUESDAY.
AN UPPER LOW/TROUGH IS PROGGED TO CRASH INTO THE WEST COAST BY EARLY
SATURDAY AND TRACK EAST TO NORTHEAST INTO THE GREAT BASIN SATURDAY
NIGHT THROUGH SUNDAY. GUIDANCE AMONG DETERMINISTIC AND ENSEMBLE
SOLUTIONS REMAIN FAIRLY ALIGNED IN TRACKING THIS SYSTEM NORTHEAST
INTO THE ROCKIES/NORTHERN HIGH PLAINS LATE SUNDAY INTO MONDAY AND
EVENTUALLY INTO OUR REGION OF THE NORTHERN PLAINS BY LATE MONDAY.
SFC LOW PRESSURE IS PROGGED TO SHIFT NORTHEAST THROUGH THE ROCKIES
INTO THE NORTHERN HIGH PLAINS SATURDAY INTO SUNDAY. THIS SYSTEM WILL
THEN TRACK EAST INTO THE DAKOTAS LATE SUNDAY INTO MONDAY. PARTS OF
THE REGION COULD SEE SOME LOW POPS STARTING AS EARLY AS LATE
SATURDAY INTO EARLY SUNDAY, BUT THE BULK OF THE MOISTURE DOESN'T
ARRIVE UNTIL THE 2ND HALF OF SUNDAY THROUGH MONDAY. POPS INCREASE
FROM 30-50 PERCENT EARLY SUNDAY TO 50-70 PERCENT BY SUNDAY NIGHT TO
60-80 PERCENT ON MONDAY. OUR FORECAST AREA WILL BEGIN TO DRY OUT ON
TUESDAY WITH JUST SOME LEFTOVER LOW END POPS THE FIRST HALF OF THE
DAY. DRIER AND COOLER CONDITIONS WILL THEN RETURN FOR LATE IN THE
PERIOD.
THIS LATE WEEKEND STORM SYSTEM WILL HAVE THE POTENTIAL TO DELIVER
MEASURABLE RAINFALL FOR MOST OF THE FORECAST AREA AS WELL AS SOME
SEVERE THUNDERSTORMS FOR OTHER PORTIONS OF THE CWA. MODELS HAVE
CONSISTENTLY BEEN HINTING THAT MOST OF THE FORECAST AREA WILL AT
LEAST SEE A QUARTER INCH OF RAINFALL TO AS MUCH AS THREE-QUARTER
INCHES WITH POTENTIAL FOR LOCALLY HIGHER AMOUNTS THAN THAT. TAKING
THE RAINFALL PROBABILITIES IN 2 CHUNKS; AMONG THE GEFS/GEPS/ENS
SOLUTIONS, THERE REMAINS A DIFFERENCE BETWEEN THE 25TH AND 75TH
PERCENTILES OF ABOUT A QUARTER OF AN INCH TO NEARLY A HALF INCH ON
AVERAGE ACROSS THE CWA FOR A 24HR ACCUMULATION ENDING AT 12Z MONDAY.
FOR THE SAME PARAMETERS FOR THE FOLLOWING 24 HR PERIOD ENDING AT 12Z
TUESDAY, THERE'S A LARGER DISCREPANCY AMONG THE 3 SOLUTIONS WITH THE
GEFS RELATIVELY CONSERVATIVE AT BETWEEN A TENTH AND TWO-TENTHS OF AN
INCH VERSUS THE GEPS/ENS MORE AGGRESSIVE BETWEEN ROUGHLY A QUARTER
INCH TO A LITTLE MORE THAN A HALF INCH. TAKING A SPLIT DOWN THE
MIDDLE USING PROBABILITIES OF SEEING A HALF INCH OR MORE OF RAINFALL
IN A 24 HR PERIOD ENDING AT 12Z MONDAY VARY ACROSS THE CWA FROM
ABOUT 15-30 PERCENT AND 20-40 PERCENT FOR THE 24 HR PERIOD ENDING AT
12Z TUESDAY WITH THE HIGHEST VALUES LOCATED ALONG OUR WESTERN AND
NORTHERN TIER OF ZONES. THE STRONG TO SEVERE CONVECTION PARAMETERS
STILL REMAIN IN PLACE MORE OR LESS WITH JOINT PROBABILITIES OF
CAPE>500 J/KG AND SHEAR>30KTS IS 25-50 PERCENT ON SUNDAY AFTERNOON
WITH THE HIGHEST VALUES WEST OF THE JAMES VALLEY. THESE HIGHEST
PROBABILITIES TRANSLATE EAST ON MONDAY WITH 30-60 PERCENT PROBS
ALONG AND EAST OF THE JAMES VALLEY. THIS STILL COINCIDES WITH SPC'S
DAY 6(MONDAY) SEVERE WEATHER OUTLOOK THAT HIGHLIGHTS OUR FAR EASTERN
ZONES(I-29 CORRIDOR AND POINTS EAST) WITH A 15% CHANCE FOR SEVERE
THUNDERSTORMS.
AVIATION /00Z TAFS THROUGH 00Z THURSDAY/
ISSUED AT 637 PM CDT WED APR 23 2025
TERMINALS KABR,KATY,KPIR,KMBG
VFR CONDITIONS WILL PREVAIL ACROSS THE AREA THIS EVENING AND
MOST OF THE OVERNIGHT. HOWEVER, EARLY THURSDAY MORNING, CIGS ARE
SUPPOSED TO BEGIN LOWERING INTO MVFR RANGE, FIRST AT KPIR BY
AROUND 12Z AND THEN AT KMBG BY 15Z, FOLLOWED BY KABR AND KATY AT
OR AFTER 18Z THURSDAY. SCATTERED TO NUMEROUS RAIN SHOWERS ARE
POSSIBLE AT KPIR FROM NOW THROUGH EARLY THURSDAY MORNING, THEN
AFTER A SHORT BREAK, THOSE SHOWER CHANCES RETURN TO THE KPIR
TERMINAL. SIMILARLY, KMBG AND KATY MAY EXPERIENCE A COUPLE OF
SHOWERS PRIOR TO 12Z THURSDAY, BUT BETWEEN ~15Z THURSDAY AND THE
END OF THE TAF VALID PERIOD, SCATTERED TO NUMEROUS RAIN SHOWERS
ARE EXPECTED AT KMBG/KABR AND KATY. SUB-VFR VISBIES MAY ACCOMPANY
ANY SHOWERS DURING THE TAF VALID PERIOD.
ABR WATCHES/WARNINGS/ADVISORIES
SD...NONE.
MN...NONE.
UPDATE...10
SHORT TERM...PARKIN
LONG TERM...VIPOND
AVIATION...10
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