Area Forecast Discussion
Issued by NWS Aberdeen, SD

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000
FXUS63 KABR 201732
AFDABR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ABERDEEN SD
1232 PM CDT SAT SEP 20 2014

.UPDATE...

SEE BELOW FOR 18Z TAF DISCUSSION.

A POTENT UPPER SHORTWAVE/PV ANOMALY IS EXPECTED TO TRACK ACROSS
THE ERN DAKOTAS AND MN THIS AFTERNOON INTO TONIGHT. THIS UPPER
FEATURE COMBINED WITH A WEAK SFC TROUGH SHOULD PROVIDE ENOUGH
FORCING FOR AT LEAST SCATTERED TSTMS OVER NERN SD AND WRN MN THIS
AFTERNOON. INSTABILITY IS EXPECTED TO REMAIN RATHER MEAGER /MLCAPE
AROUND 500 J/KG/ BUT DEEP LAYER WILL BE IMPRESSIVE /40+
KNOTS/...SO WOULD NOT BE SURPRISED TO SEE A FEW MINI-SUPERCELL TYPE
STORMS. AS MENTIONED...MID-LEVEL FLOW IS QUITE STRONG SO EXPECTING
WINDS TO BE THE PRIMARY THREAT AS STRONG WINDS ARE TRANSLATED TO
THE SFC...BUT MARGINALLY SEVERE HAIL IS ALSO POSSIBLE DUE TO LOWER
FREEZING LEVELS AND POTENTIAL FOR ROTATING STORMS. THE SPC DAY 1
FORECAST PULLED THE SLIGHT RISK AS FAR WEST AS KABR...AND THIS
LOOKED REASONABLE. ALSO WATCHING THE POTENTIAL FOR GUSTY NW WINDS
ACROSS THE WEST BEHIND THE SFC TROUGH...BUT AT THIS POINT STILL
FEEL THEY SHOULD REMAIN BELOW ADVISORY LEVELS. UPDATES ALREADY
OUT.

&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TODAY THROUGH MONDAY

COLD FRONT ON TRACK TO DROP SOUTHEAST ACROSS THE CWA THIS
AFTERNOON...BRINGING FAIRLY STRONG AND GUSTY NORTHWEST
WINDS...ESPECIALLY ACROSS CENTRAL SD. BUFKIT SOUNDINGS APPEAR
MARGINAL FOR WIND ADVISORY AND MAY EVEN GET INTO LOW END CRITERIA
FOR AN HOUR OR TWO WITH SUSTAINED SPEEDS. NO ADVISORY AT THIS TIME
AS IT APPEARS HIGHEST SPEEDS AND GREATEST IMPACTS WILL BE FELT
ACROSS NORTHWEST SOUTH DAKOTA. SOMETHING TO MONITOR THOUGH AS THE
DAY PROGRESSES. OTHERWISE...WILL BE WATCHING THUNDERSTORMS ALONG
THE FRONT AS IT DROPS SOUTHEAST. NICE MID LEVEL JET MAX MOVES
ACROSS THE DAKOTAS TODAY WITH FAVORABLE EXIT REGION CENTERED OVER
THE RED RIVER VALLEY. LOW LEVEL MOISTURE IS MARGINAL...WHICH LEADS
TO FAIRLY MEAGER MLCAPE VALUES. ALTHOUGH...0-6KM BULK SHEAR AND
STRONG CONVERGENCE ALONG FRONT WILL GIVE WAY TO A BROKEN LINE OF
SHOWERS AND STORMS ACROSS EASTERN ND THIS AFTERNOON AND EVENTUALLY
MOVING INTO MN. THE SOUTHERN EXTENT OF THIS LINE MAY MAKE ITS WAY
INTO THE NORTHEASTERN CWA. HI RES MODELS ALL SHOWING THE LINE OF
STORMS MOVING OVER THE RED RIVER VALLEY...BUT VARY A BIT IN ITS
SOUTHERN EXTENT INTO THE NORTHEAST CWA. GIVEN THE IMPRESSIVE
FORCING AND FORWARD MOTION OF THE FRONT...EXPECTING STRONG WINDS
TO BE THE MAIN THREAT WITH ANY STRONGER STORMS. BEST AREA THOUGH
IS ACROSS RED RIVER VALLEY AND ON INTO MN...BUT WOULD NOT BE
SURPRISED IF A FEW STORMS SNEAK INTO THE FAR NORTHEAST COUNTIES.

REST OF THE SHORT TERM IS QUIET AS SFC HIGH PRESSURE FOLLOWS THE
FRONT OVERNIGHT INTO SUNDAY. THIS WILL BE THE DOMINATE FEATURE
THROUGH MONDAY...WITH DRY CONDITIONS AND COOLER TEMPERATURES. THE
TERM COOLER IS USED LOOSELY AS TEMPS WILL STILL BE RATHER MILD
WITH READINGS IN THE 60S AND 70S...JUST A BIT COOLER THAN WHAT WE
HAVE BEEN SEEING THE PAST COUPLE DAYS.


.LONG TERM...MONDAY NIGHT THROUGH SATURDAY

THE PERIOD OPENS WITH AN UPPER LEVEL LOW AND SFC TROUGH MOVING
INTO THE REGION. STUCK WITH ALLBLEND SLIGHT CHANCE TO CHANCE POPS
WITH THIS SYSTEM THROUGH WED MORNING. FOR REFERENCE THOUGH THE
0Z GFS IS A LITTLE DRIER AND DOES NOT CARRY THE PRECIP AS FAR
NORTH AS THE ECMWF AND THE ALLBLEND. THIS MAY BE SOMETHING TO
WATCH IF IT BECOMES A PERSISTENT TREND. BY WED NIGHT UPPER LEVEL
RIDGING BEGINS TO BUILD BACK IN OVER THE PLAINS. TEMPERATURES WILL
BE ABOVE AVERAGE THROUGH THE PERIOD WITH HIGHS IN THE 70S TO LOWER
80S.








&&

.AVIATION...
18Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS

EXPECT PREDOMINANTLY VFR CIGS/VISBY THROUGH THE TAF PERIOD. SYSTEM
MOVING THROUGH EASTERN NORTH DAKOTA INTO WESTERN MINNESOTA TODAY
WILL SUPPORT A FEW ELEVATED SHOWERS FOR KABR/KATY
TERMINALS THIS AFTERNOON...MAYBE A RUMBLE OF THUNDER...BUT BEST
CHANCE FOR STORMS ARE EAST OF THESE TERMINALS. WINDS WILL INCREASE
TODAY OUT OF THE SOUTHWEST/NORTHWEST AS A SURFACE TROF PASSES
OVERHEAD AS WELL.


&&

.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&

$$
UPDATE...FOWLE
SHORT TERM...TMT
LONG TERM...WISE
AVIATION...CONNELLY

WEATHER.GOV/ABERDEEN





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