AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE ABERDEEN SD
640 AM CDT SAT MAY 18 2013
.UPDATE...
AVIATION DISCUSSION HAS BEEN UPDATED.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TODAY THROUGH MONDAY
AN AREA OF LOW PRESSURE WILL SLOWLY MOVE THROUGH SD. ALONG AND
AHEAD OF THE TROF AXIS THERE IS ABUNDANT LOW LEVEL MOISTURE WITH A
DECENT 25 TO 30 KT LLJ. A SERIES OF EMBEDDED H7 AND H5 SHORTWAVES
WILL ALSO HELP AMPLIFY CONVECTIVE POTENTIAL ALONG AND EAST OF A
LINE FROM ABERDEEN TO PIERRE. SOME OF THE CONVECTION CURRENTLY
ONGOING IS EXPECTED TO LINGER INTO THE MID MORNING HOURS IN THE
NORTH TODAY. THERE MAY BE SOME STRATUS CIG DEVELOPMENT IN THE WAKE
OF OVERNIGHT AND EARLY MORNING ACTIVITY THAT WILL INHIBIT
CONVECTIVE DEVELOPMENT TODAY. THINKING THAT ANY LOWER CIGS WILL
ERODE BY AFTERNOON. SOME TSTORMS WILL THEN BE POSSIBLE DOWN NEAR
KPIR AND AREAS AROUND I-90. INSTABILITY INCREASES BETWEEN 03Z AND
09Z ALONG THE COTEAU WHERE BULK SHEAR GROWS TO AROUND 45 KTS. CAPE
WILL BE ABUNDANT AT AROUND 2500 TO 3500 J/KG THROUGH THE DAY.
LARGE HAIL WILL BE THE PRIMARY CONCERN.
RAIN AND TSTORM CHANCES WILL CONTINUE SUNDAY AND MONDAY AS THE SFC
LOW OCCLUDES OVER MN AND THE UPPER TROF MOVES EAST...CREATING A
FAIRLY WELL STACKED LOW PRESSURE SYSTEM. HIGH PWATS WILL MEAN THE
CHANCE FOR HEAVY RAIN. GREATEST CHANCES FOR INSTABILITY IN TSTORMS
WILL CONTINUE AHEAD OF THE LOW...SO SEVERE TSTORMS STILL A
POSSIBILITY SUNDAY MORNING ACROSS EASTERN SD AND WEST CENTRAL MN.
.LONG TERM...MONDAY NIGHT THROUGH FRIDAY
EXTENDED MODEL SOLUTIONS AGREE FAIRLY WELL ACROSS THE CONUS
THROUGH THE FORECAST PERIOD. THE PERIOD BEGINS WITH A CLOSED UPPER
LEVEL LOW PRESSURE SYSTEM SITUATED OVER THE EASTERN DAKOTAS AND
WESTERN MINNESOTA. THIS SYSTEM WILL BRING PERIODS OF SHOWERS
THROUGH AT LEAST WEDNESDAY EVENING BEFORE DEPARTING THE REGION.
LIMITED HEATING DUE TO EXTENSIVE CLOUD COVER WILL KEEP
TEMPERATURES VERY COOL WITH HIGHS SOME 10 TO 15 DEGREES BELOW
NORMAL ON TUESDAY AND WEDNESDAY. UPPER LEVEL RIDGING WILL
EVENTUALLY MOVE INTO THE REGION BY THURSDAY WITH WARMER AND DRIER
CONDITIONS PREVAILING THROUGH THE REST OF THE PERIOD.
&&
.AVIATION...
12Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
ASIDE FROM EARLY MORNING IFR FOG FOR THE KABR TERMINAL...VFR
CONDITIONS CAN BE EXPECTED THROUGH MOST OF THE DAY. SHOWERS AND
THUNDERSTORMS ARE EXPECTED LATER THIS AFTERNOON AND THROUGH THE
OVERNIGHT HOURS. SOME THUNDERSTORMS WILL HAVE POTENTIAL TO PRODUCE
SPORADIC WIND GUSTS ALONG WITH MVFR/IFR CONDITIONS.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
UPDATE...SD
SHORT TERM...WISE
LONG TERM...SD
AVIATION...SD
WEATHER.GOV/ABERDEEN
