468
FXUS63 KABR 180529
AFDABR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ABERDEEN SD
1229 AM CDT MON MAY 18 2026
KEY MESSAGES
- SLIGHT RISK FOR SEVERE WEATHER (2 OF 5) FOCUSED ACROSS FAR
NORTHEAST SOUTH DAKOTA AND WEST CENTRAL MINNESOTA THIS
AFTERNOON/EVENING. MARGINAL RISK FOR SEVERE WEATHER (1 OF 5)
INCLUDES PARTS OF THE NORTHEAST AND CENTRAL SOUTH DAKOTA. MAIN
THREAT IS LARGE HAIL.
- COLDER AIR RETURNS MONDAY THROUGH WEDNESDAY, WITH HIGH
TEMPERATURES AROUND 15 TO 20 DEGREES BELOW NORMAL.
TEMPERATURES WEDNESDAY MORNING MAY DROP TO NEAR OR BELOW
FREEZING, BRINGING THE POTENTIAL FOR FROST.
UPDATE
ISSUED AT 1229 AM CDT MON MAY 18 2026
UPDATE FOR 06Z TAF ISSUANCE.
UPDATE ISSUED AT 856 PM CDT SUN MAY 17 2026
AS THE COOL STABLE SURFACE LAYER DEEPENS ON NORTH-NORTHWEST CAA
WINDS, GOT ONE LONE (ELEVATED) CELL MOVING NORTHEAST INTO GRANT
COUNTY SD AT THIS TIME. MAYBE SOME HEAVY RAINFALL AND PEA-
SIZED HAIL WITH IT PRESENTLY. PRECIPITATION HAS BEEN MIGRATING
NORTH AND EAST INTO THE FAR NORTHEAST CORNER OF THE STATE OVER
THE PAST SEVERAL HOURS. WITHIN A COUPLE OF HOURS, THIS ACTIVITY
SHOULD CLEAR THE FAR NORTHEAST CORNER OF THE CWA. NO CHANGES
PLANNED TO THE TONIGHT PERIOD FORECAST. THE POTENTIALLY COOLEST
AREA OF THE CWA OVERNIGHT LOOKS TO BE NORTH CENTRAL SOUTH
DAKOTA, WHILE THE POTENTIALLY WARMEST AREA LOOKS TO BE NORTHEAST
SOUTH DAKOTA INTO WEST CENTRAL MINNESOTA.
UPDATE ISSUED AT 642 PM CDT SUN MAY 17 2026
SEE BELOW FOR AN AVIATION FORECAST DISCUSSION FOR THE 00Z TAFS.
DISCUSSION
ISSUED AT 120 PM CDT SUN MAY 17 2026
AFTER THE FIRST ROUND OF SHOWERS AND STORMS MOVED THROUGH PORTIONS
OF CENTRAL SD THIS MORNING, MOST OF THE FORECAST AREA HAS BEEN IN
BETWEEN AREAS OF PRECIPITATION WITH THE SECOND ROUND NOW MOVING INTO
OUR SOUTH/WEST ZONES. THIS IS IN ASSOCIATION WITH THE NEXT UPPER
WAVE AND INVERTED SFC TROUGH THAT HAS POKED NORTHWARD INTO CENTRAL
SECTIONS OF SD. THE MAIN LOW PRESSURE CENTER REMAINS TO OUR SOUTH
ACROSS PARTS OF NE/KS AND IT IS PROGGED TO SHIFT NORTHEAST BY LATE
THIS AFTERNOON INTO SIOUX FALLS/SIOUX CITY AREA. OF THE
AFOREMENTIONED AREA OF PRECIP, AN AREA OF STRONGER ELEVATED
CONVECTION ACROSS NORTH CENTRAL NE AT MIDDAY IS PROGGED TO TRACK
NORTHEAST INTO SD THROUGH THE EARLY AFTERNOON. THIS AREA OF
CONVECTION APPEARS TO BE LOCATED AROUND A MESO LOW AND ATTENDANT
COLD FRONT THAT IS CENTERED AND DRAPED NORTH TO SOUTH TOWARD THE
PARENT LOW ACROSS THE NE/KS BORDER. RAP GUIDANCE SHOWS AN
INSTABILITY GRADIENT SET UP IN THE VICINITY OF THIS CONVECTION
ACROSS NORTHERN NE INTO FAR SOUTH CENTRAL SD. THIS GUIDANCE PROGS
THIS GRADIENT TO TRACK NORTHEAST FROM AINSWORTH, NE TOWARD MITCHELL
AND HURON SD THE FIRST PART OF THE AFTERNOON AND THEN ON INTO OUR
FAR SOUTHEAST ZONES AROUND THE WATERTOWN AREA MID TO LATE AFTERNOON.
NORTH OF THE ELEVATED CONVECTION, WE SEE AN AREA OF MODERATE TO
EMBEDDED HEAVY RAIN SHIFTING INTO THE PIERRE AREA(I-90 CORRIDOR) AND
POINTS NORTH TOWARD MOBRIDGE. THESE RAINS WILL BE JUST THAT AND NOT
POSE ANY SEVERE THREATS TO CENTRAL SD THROUGH THE AFTERNOON. VISIBLE
SAT SHOWS EXTENSIVE CLOUD COVER(MOSTLY STRATUS) ALONG AND WEST OF
THE JAMES VALLEY THROUGH CENTRAL SD. CLEAR TO PARTLY CLOUDY SKIES
HAVE DEVELOPED ACROSS EAST CENTRAL AND SOUTHEAST SD WHICH WILL HELP
TO CONTRIBUTE TO DESTABILIZATION AND A MORE FAVORABLE ENVIRONMENT
FOR STRONG/SEVERE CONVECTION THIS AFTERNOON. RAP MODEL DOES PROG
MLCAPE VALUES OF 1000-1500 J/KG ACROSS EAST CENTRAL SD/WEST CENTRAL
MN BY MID TO LATE AFTERNOON WITH AMPLE BULK SHEAR VALUES OF 45-55
KTS. CAM SOLUTIONS TRACK THAT ELEVATED CONVECTION NORTHEAST FROM
SOUTH CENTRAL SD INTO PARTS OF SOUTHEAST SD WITH ADDITIONAL
DEVELOPMENT POSSIBLE TO THE NORTH THAT WOULD AFFECT SOME OF OUR
FORECAST AREA SUCH AS MILLER TO REDFIELD, CLARK, WATERTOWN AND
ORTONVILLE THROUGH THE COURSE OF THE AFTERNOON HOURS. THE MAIN
CONCERN WITH ANY OF THE STRONGER CONVECTIVE CELLS WILL BE LARGE HAIL
AND DAMAGING WINDS WITH A MORE ISOLATED RISK FOR A TORNADO OR TWO
AND OF COURSE LOCALLY HEAVY RAINFALL.
BY LATE THIS AFTERNOON AND EVENING, GUIDANCE PROGS THIS ACTIVITY AND
ANY GENERIC SHOWERS AND STORMS LOCATED FARTHER NORTH AND WEST TO
SHIFT EASTWARD INTO THE JAMES VALLEY AND POINTS EAST. BY EARLY TO
MID EVENING, MOST OF THE THIS ACTIVITY IS EXPECTED TO BEGIN TO SHIFT
EAST AND OUT OF OUR FORECAST AREA INTO WESTERN MN. A BREAK IN THE
PRECIP IS THEN EXPECTED TONIGHT INTO MONDAY MORNING BEFORE THE NEXT
ROUND OF MOISTURE SHIFTS NORTH AND EAST BACK INTO OUR REGION FOR
MONDAY AFTERNOON AND MONDAY NIGHT. THIS WILL BE MORE STRATO-FORM
RAINFALL WITH NO RISK FOR SEVERE WEATHER EXPECTED. INCREASING
NORTHERLY BREEZES AND TEMPERATURES COOLING INTO THE UPPER 40S TO MID
50S IS ABOUT AS BEST WE BE ABLE TO MANAGE FOR MONDAY. BY TUESDAY
MORNING, MOST IF NOT ALL THE PRECIP WILL BE GONE AND WE SHOULD BE
LEFT WITH MOSTLY DRY CONDITIONS ALBEIT STILL COOL. THIS COOLER THAN
NORMAL AIR MASS WILL MAINTAIN ITSELF ACROSS OUR AREA TUESDAY NIGHT
INTO WEDNESDAY. IN FACT, WE SHOULD SEE 2 OVERNIGHT'S WORTH OF FROSTY
OR NEAR FROSTY LIKE TEMPERATURES IN THE 30S. LATE TUESDAY NIGHT INTO
WEDNESDAY MORNING STILL LOOKS TO BE THE COLDEST WITH FORECASTED
OVERNIGHT LOWS IN THE UPPER 20S TO MID 30S. MORE GUIDANCE HAS
LATCHED ONTO THIS IDEA LEADING TO HIGHER CONFIDENCE THAT A GOOD
PORTION OF OUR FORECAST AREA WILL SEE FROST.
AVIATION /06Z TAFS THROUGH 06Z TUESDAY/
ISSUED AT 1229 AM CDT MON MAY 18 2026
TERMINALS KABR,KATY,KPIR,KMBG
IFR TO LOW END MVFR CEILINGS ARE FORECAST THROUGH THE NEXT 24
HOURS. FOG IS FORECAST AT ATY EARLY THIS MORNING (VISIBILITY
DOWN TO 8SM SHORTLY AT 05Z MONDAY. LIGHT RAIN WILL DOMINATE THE
AFTERNOON HOURS.EXPECT WINDS TO REMAIN OUT OF THE NORTH TO
NORTH-NORTHWEST WITH GUSTS OF 20-30KTS.
ABR WATCHES/WARNINGS/ADVISORIES
SD...NONE.
MN...NONE.
UPDATE...10
DISCUSSION...VIPOND
AVIATION...06
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