422
FXUS63 KABR 141723 AAC
AFDABR
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE ABERDEEN SD
1223 PM CDT MON SEP 14 2026
KEY MESSAGES
- WIDESPREAD RAIN SHOWERS AND WEAK THUNDERSTORMS MOVE INTO THE
AREA EARLY THIS MORNING, CONTINUING INTO THE AFTERNOON. THE
HEAVIEST PRECIPITATION IS EXPECTED AFTER SUNRISE OVER PARTS OF
EASTERN SOUTH DAKOTA AND WESTERN MINNESOTA, WHERE SOME AREAS
MAY SEE UPWARDS OF AN INCH OF PRECIPITATION THROUGH THIS
EVENING. ELSEWHERE, EXPECT AROUND HALF AN INCH OF RAIN IN
TOTAL.
- STRONG NORTHWESTERLY WINDS WILL INCREASE BEHIND A COLD FRONT
THIS AFTERNOON INTO EVENING. WIND GUSTS WILL RANGE BETWEEN 40
TO 55 MILES PER HOUR THIS AFTERNOON THROUGH TONIGHT. A WIND
ADVISORY HAS BEEN ISSUED FOR NORTH CENTRAL SOUTH DAKOTA.
- COMBINATION OF STRONG WINDS AND HUMIDITY BELOW 40 PERCENT WILL
LEAD TO HIGH TO VERY HIGH FIRE DANGER THIS AFTERNOON ACROSS
CENTRAL AND NORTH CENTRAL SOUTH DAKOTA. AN INCREASE IN
HUMIDITY WILL LIMIT FIRE WEATHER CONCERNS FURTHER EAST.
UPDATE
ISSUED AT 1214 PM CDT MON SEP 14 2026
UPDATED DISCUSSION FOR THE 18Z TAFS BELOW.
UPDATE ISSUED AT 1011 AM CDT MON SEP 14 2026
AS OF 15Z, THE CENTER OF LOW PRESSURE IS HOVERING OVER
NORTHWESTERN ND/MT INTO CANADA WITH THE OCCLUDED FRONT EXTENDING
SOUTHWARD THROUGH THE WESTERN DAKOTAS AND SECONDARY LOW OVER
SOUTHWESTERN SD WITH ITS WARM FRONT THROUGH NE/KS. SCATTERED TO
WIDESPREAD ELEVATED SHOWERS AND THUNDERSTORMS CONTINUE ON THE
WAA SIDE OF THE SYSTEM WITH THE BULK OF THE PRECIP ALONG AND
EAST OF THE COTEAU WITH ADDITIONAL AREA OF PRECIP OVER SOUTH
CENTRAL AND THROUGH NORTHEASTERN SD. PWAT VALUES ARE AROUND
1.5-1.8" (HIGHEST EASTERN CWA) WITH STRONG 925/850MB MOISTURE
TRANSPORT FROM THE SOUTH AND SOUTHEAST. OVERALL RAIN TOTALS HAVE
RANGED FROM AROUND A HALF INCH IN MBG, .08" IN ABR WITH MBG/ATY
AROUND 0.1". AS THE FRONT TRACKS EASTWARD, SO WILL THE PRECIP
WITH THE POSSIBILITY OF ADDITIONAL DEVELOPMENT THROUGH THE
MORNING OVER CENTRAL SD AND AFTERNOON JAMES VALLEY AND EASTWARD.
THE LAST OF THE PRECIP IS FORECAST TO EXIT EASTERN SD/MN BY
LATE AFTERNOON TO EARLY EVENING. BEHIND THE FRONT, WINDS WILL
INCREASE WITH GUSTS OF 30-50MPH THIS AFTERNOON AND EVENING,
HIGHEST OVER NORTH CENTRAL SD WITH TEASE STRONGER WINDS
SPREADING EASTWARD TONIGHT. OTHER THAN MINOR UPDATES TO POPS,
FORECAST REMAINS ON TRACK.
UPDATE ISSUED AT 628 AM CDT MON SEP 14 2026
SEE BELOW FOR AN AVIATION FORECAST DISCUSSION FOR THE 12Z TAFS.
DISCUSSION
ISSUED AT 247 AM CDT MON SEP 14 2026
RAIN SHOWERS AND WEAK THUNDERSTORMS ARE MOVING INTO THE FORECAST
AREA FROM THE SOUTHWEST THIS MORNING. EXPECTATIONS OVER THE NEXT
COUPLE OF HOURS IS THAT COVERAGE OF THESE SHOWERS AND STORMS WILL
CONTINUE TO EXPAND, COVERING MOST IF NOT ALL OF THE FORECAST AREA BY
SUNRISE. THESE SHOWERS AND STORMS ARE FUELED BY A 40-50 KNOT LOW-
LEVEL JET MOVING ACROSS THE REGION THIS MORNING, STRENGTHENING TO 55
KNOTS AS IT PROGRESSES EASTWARD AFTER SUNRISE. IN ADDITION TO THE
STORM DEVELOPMENT, THIS LOW-LEVEL JET IS EXPECTED TO BRING STRONG
SOUTHERLY GUSTS UP TO 40 MILES PER HOUR TO MUCH OF NORTHEASTERN
SOUTH DAKOTA AND WESTERN MINNESOTA THIS MORNING. STILL ANTICIPATING
THE HIGHEST RAINFALL TOTALS OVER EASTERN SOUTH DAKOTA, AND NBM
MEDIAN VALUES THROUGH TONIGHT SIT AROUND 1"-1.25" OVER CODINGTON
COUNTY AND THE SURROUNDING COUNTIES. AS MENTIONED IN PREVIOUS
DISCUSSIONS, THERE IS AN OUTSIDE CHANCE OF FLOODING POTENTIAL GIVEN
THE ABNORMALLY HIGH PWAT VALUES ADVECTED INTO THE REGION (AROUND
1.5"-1.75", WELL ABOVE THE 90TH PERCENTILE FOR MID-SEPTEMBER), FULL
SATURATION THROUGH THE PROFILE, AND A WARM CLOUD LAYER DEPTH OF
ROUGHLY 11-12K FEET. HOWEVER, ANTECEDENT CONDITIONS ARE NOT VERY
FAVORABLE FOR FLOODING, AND MUCH OF EASTERN SOUTH DAKOTA IN
PARTICULAR IS UNDER D0-D1 DROUGHT. STORM MOTION IS ALSO EXPECTED TO
BE FAIRLY QUICK, ALTHOUGH WITH THE LOW-LEVEL JET IN PLAY THE
DEVELOPMENT OF TRAINING STORMS CANNOT BE RULED OUT. PERHAPS THE
BIGGEST LIMITING FACTOR THOUGH IS THE LACK OF CAPE. GENERALLY
EXPECTING LESS THAN 1000 J/KG OF MUCAPE, ALTHOUGH IT SHOULD BE NOTED
THAT VALUES SEEM TO BE INCREASING OVER THE PAST COUPLE OF FORECAST
CYCLES. STILL, NOT EXPECTING MUCH IN THE WAY OF STRONG THUNDERSTORMS
OR SEVERE WEATHER WITH THIS DEVELOPMENT, BUT WILL CONTINUE TO KEEP A
CLOSE EYE THROUGH THE MORNING HOURS.
AFTER THE PASSAGE OF THE COLD FRONT, WINDS WILL TURN NORTHWESTERLY
AND INCREASE. THE STRONGEST WINDS, GUSTING UPWARDS OF 35 MILES PER
HOUR, ARE EXPECTED ALONG AND WEST OF THE MISSOURI RIVER,
PARTICULARLY OVER CORSON AND DEWEY COUNTIES. NBM PROBABILITY OF
REACHING 45 MILE PER HOUR GUSTS IN THOSE TWO COUNTIES SITS IN THE 40-
60% RANGE FROM AROUND NOON MONDAY THROUGH MIDNIGHT MONDAY NIGHT.
ELSEWHERE, BOTH NBM AND HREF PROBABILITIES OF REACHING WIND ADVISORY
CRITERIA STRUGGLE TO REACH MORE THAN 20-30%. HOWEVER THE COMBINATION
OF THE STRONG COLD AIR ADVECTION COMING IN BEHIND, A SHALLOW DIURNAL
INVERSION AT THE SURFACE, AND THE TENDENCY FOR THE NBM IN PARTICULAR
TO VERIFY NEAR THE 90TH PERCENTILE UNDER THIS TYPE OF SETUP, THERE
IS SOME SLIGHTLY INCREASED CONFIDENCE GIVEN TO NEEDING AN ADVISORY
OVER CAMPBELL/WALWORTH/MCPHERSON/EDMUNDS COUNTIES. THEREFORE, HAVE
EXPANDED THE COVERAGE ON THE PREVIOUS ADVISORY, RUNNING THE NEW
ADDITIONS FROM 00Z-09Z TUESDAY. THE POTENTIAL FAILURE POINT HERE
WOULD BE IF THE INVERSION HOLDS, BUT GIVEN THE EXPECTED TEMPERATURE
DROPS AT 850MB (NEARLY 10 DEGREES CELSIUS IN 6 HOURS), THE PROFILE
WILL LIKELY THAN NOT BE ABLE TO MAINTAIN SOME DEGREE OF MIXING TO
THE SURFACE.
IN ADDITION TO ADVISORY LEVEL CRITERIA, WINDS DURING THE AFTERNOON
WILL BE THE DRIVER BEHIND SOME ELEVATED FIRE WEATHER CONCERNS. A
BRIEF WARMUP IN TEMPERATURES THIS AFTERNOON OUT AHEAD OF THE FRONT
OVER CENTRAL AND NORTH CENTRAL SOUTH DAKOTA WILL PUSH AFTERNOON
HUMIDITY DOWN BELOW 40 PERCENT OVER THE WESTERNMOST COLUMN OF
COUNTIES IN THE ABERDEEN CWA. THE COMBINATION OF THE WIND AND LOW
HUMIDITY, IN ADDITION TO FUEL STATUS CONSIDERATIONS, LEADS TO THE
GRASSLAND FIRE DANGER INDEX REACHING VERY HIGH IN THAT AREA.
COUNTIES JUST TO THE EAST OF THE PREVIOUSLY MENTIONED AREA WILL
REACH HIGH GRASSLAND FIRE DANGER AS WELL.
BY MID-WEEK, THE UPPER-LEVEL SETUP WILL TRANSITION TO NEAR-ZONAL
FLOW AND A POSITIVELY TILTED TROUGH OVER THE WESTERN CONUS. THIS
SETUP WILL ALLOW FOR ADDITIONAL SHORTWAVES INTO THE REGION, LEADING
TO MORE CHANCES FOR RAIN LATER IN THE WEEK. SPECIFICALLY, WEDNESDAY
AND FRIDAY BOTH SPORT CHANCES FOR RAIN AT THIS TIME. MODEL SOUNDINGS
FOR BOTH OF THOSE DAYS DO NOT LOOK PARTICULARLY FAVORABLE FOR ANY
SEVERE WEATHER POTENTIAL, ALTHOUGH PERHAPS A TOUCH TO EARLY TO SAY
FOR CERTAIN ON FRIDAY IN PARTICULAR. ALSO EXPECTING A GRADUAL
WARMING TREND WITH THIS SETUP, WITH MEDIAN HIGH TEMPERATURES
REACHING NEAR-NORMAL (MID-70S) OVER THE WEEKEND.
AVIATION /18Z TAFS THROUGH 18Z TUESDAY/
ISSUED AT 1214 PM CDT MON SEP 14 2026
TERMINALS KABR,KATY,KPIR,KMBG
RAIN HAS ENDED AT KPIR/KMBG WITH LIGHT TO MODERATE RAIN CONTINUING
AT KABR/KATY AS THE BACK EDGE OF THE PRECIP IS JUST WEST OF THE
JAMES RIVER. AS THE FRONT CONTINUES TO TRACK EASTWARD, THE LAST
OF THE RAIN SHOULD EXIT FAR EASTERN SD/MN BY LATER THIS
AFTERNOON TO EARLY THIS EVENING. MVFR/IFR CIGS PER LOW STRATUS
WILL DECREASE WEST TO EAST BEHIND THE FRONT THROUGH THE LATE
AFTERNOON AND EVENING WITH CEILINGS INCREASING. VFR CIGS ARE
THEN FORECAST THROUGH THE REST OF THE TAF PERIOD.
BEHIND THE FRONT PER COLDER AIR, PRESSURE RISES, AND STRONGER
WINDS ALOFT WILL MIX DOWN WITH WINDS INCREASING WEST TO EAST
ACROSS THE REGION WITH GUSTS OF 30 TO 55 MPH OUT OF THE
WEST/NORTHWEST THIS AFTERNOON THROUGH EARLY TUESDAY MORNING.
HIGH PRESSURE WILL FILTER IN, DIMINISHING THE WINDS THROUGH
TUESDAY.
ABR WATCHES/WARNINGS/ADVISORIES
SD...WIND ADVISORY UNTIL 1 AM MDT TUESDAY FOR SDZ003-015.
WIND ADVISORY FROM 7 PM THIS EVENING TO 4 AM CDT TUESDAY FOR
SDZ004-005-009-010.
MN...NONE.
UPDATE...MMM
DISCUSSION...BC
AVIATION...MMM
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