000
FXUS63 KABR 162021
AFDABR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ABERDEEN SD
321 PM CDT THU MAY 16 2013

.SHORT TERM...THROUGH SATURDAY AM

PAIR OF SHORTWAVES SPLITTING THE CWA...WITH CONVECTIVE CLUSTERS
OVER CENTRAL NORTH DAKOTA AND SOUTH CENTRAL SOUTH DAKOTA. BETWEEN
THESE TWO FEATURES...A TONGUE OF MILD/DRY AIR HAS KEPT MOST
WEAK RETURNS FROM REACHING THE GROUND. A COUPLE OF BOUNDARIES HAVE
ALSO MOVED THROUGH THE AREA...THE RESULT OF EVAPORATE COOLING.

MODELS PUSH THE CONVECTIVE CLUSTER OVER SOUTH CENTRAL SOUTH DAKOTA
ON A EAST/NORTHEAST TRAJECTORY...WITH REDFIELD AND WATERTOWN
EXPECTED TO BE ON THE NORTHERN PERIPHERY. TO THE NORTH OF THESE
LOCATIONS...LIGHT SHOWERS/SPRINKLES ARE ABOUT IT. A COOL...STABLE
LOW LEVEL AIRMASS WILL REMAIN IN PLACE TONIGHT AND INTO
FRIDAY UNDER NORTHEAST FLOW...WITH INCREASING HEIGHTS
ALOFT...SUGGESTING DRY CONDITIONS GOING THROUGH FRIDAY AFTERNOON
MOST OF THE AREA.

THERE IS AN EXCEPTION HOWEVER FOR FRIDAY EVENING. SOUNDINGS
SUGGEST ENOUGH POTENTIAL TO BREAK THE CAP...PARTICULARLY IN SOUTH
CENTRAL SOUTH DAKOTA. CANT RULE OUT A STORM OR TWO...AIDED BY A
SHORTWAVE ENCROACHING FROM THE SOUTH AND A RAPIDLY DEVELOPING 40
KT LOW LEVEL JET. LOW LEVEL JET ENHANCED CONVECTION WILL THEN
SPREAD ACROSS THE CWA FROM WEST TO EAST...WITH ABOUT 1000 J/KG
ELEVATED CAPE OVERNIGHT. OVERALL WIND SHEAR IS RATHER WEEK...WHICH
WILL BE LIMITING FACTOR IN SEVERE POTENTIAL...HOWEVER THERE WILL
BE SOME DECENT DIRECTIONAL SHEAR IN THE LOW LEVELS IF ANY STORMS
RIDE NORTH OF THE WARM FRONT.


.LONG TERM...SATURDAY THROUGH THURSDAY
GFS ENSEMBLES AND OPERATIONAL MODELS STILL HAVE GREAT AGREEMENT
AND CONSISTENCY IN THE LONG TERM. A STRONG UPPER LEVEL NEGATIVE
TILT TROUGH WILL LIFT OUT OF THE SOUTHWEST US INTO THE NORTHERN
PLAINS REGION AND CLOSE OFF THROUGH SUNDAY NIGHT. THEN THE CLOSED
UPPER LOW PRESSURE AREA WILL MAKE VERY LITTLE MOVEMENT EASTWARD
THROUGH THE REST OF THE LONG TERM BRINGING CHANCES OF PRECIPITATION
FROM SATURDAY INTO WEDNESDAY. HAVE IN VERY GOOD CHANCES OF SHOWERS
AND THUNDERSTORMS INTO TUESDAY AT THIS TIME. SATURDAY STILL LOOKS
LIKE IT COULD BE A SEVERE WEATHER DAY FOR PARTS OF THE CWA AS
EVERYTHING COMES TOGETHER FOR SEVERE THUNDERSTORM DEVELOPMENT. A
WARM FRONT WILL BE EXTENDING ACROSS THE NORTHERN PART OF THE CWA.
WITH TEMPERATURES RISING INTO THE 80S ALONG WITH GOOD
DEWPOINTS...INSTABILITY SHOULD BUILD UP THROUGH THE DAY. WITH GOOD
DEEP LAYER SHEAR ALONG WITH A GOOD LLJ...THE SETUP APPEARS GOOD
FOR NUMEROUS THUNDERSTORMS TO DEVELOP WITH SOME SEVERE STORMS.
OTHERWISE...WITH COOLER NORTHERLY FLOW ALONG WITH CLOUDS AND
RAINFALL...TEMPERATURES WILL COOL INTO THE 60S INTO MONDAY AND
REMAIN THAT WAY THROUGH MOST OF THE REST OF THE LONG TERM.



&&

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

A SHORT WAVE LOW PRESSURE TROUGH AND WAA WERE BRINGING MID LEVEL
CLOUDS ALONG WITH SOME MAINLY LIGHT SHOWERS TO CENTRAL AND NORTH
CENTRAL SOUTH DAKOTA EARLY THIS AFTERNOON. WITH NOT MUCH FOR
INSTABILITY ALONG WITH HIGH CLOUD BASES AND BIG DEW POINT
SPREADS/LOW LEVEL DRY AIR ACROSS THE REGION...DONT EXPECT MUCH
FOR ANY THUNDER WITH THIS AREA AS IT MOVES EAST INTO THE EVENING
ALONG WITH RAINFALL AT THE SURFACE. THUS...HAVE VFR MID LEVEL
CLOUDS IN THE TERMINALS ALONG WITH SHOWERS AT OR IN THE VICINITY
OF THE TERMINALS INTO THE AFTERNOON AND EVENING HOURS.



&&

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

$$
SHORT TERM...CONNELLY
LONG TERM...MOHR
AVIATION...MOHR

WEATHER.GOV/ABERDEEN