000
FXUS63 KABR 172101
AFDABR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ABERDEEN SD
401 PM CDT FRI MAY 17 2013

.SHORT TERM...TONIGHT THROUGH SUNDAY NIGHT
THE MODELS ALL AGREE WELL AND CONTINUE TO BE VERY CONSISTENT AT
BRINGING THE UPPER LEVEL LOW PRESSURE TROUGH OUT OF THE SOUTHWEST
US THROUGH SUNDAY NIGHT AND CLOSING IT OFF. THUNDERSTORMS ARE
BEGINNING TO DEVELOP IN WESTERN SOUTH DAKOTA LATE THIS AFTERNOON
AND WILL CONTINUE TO DEVELOP AND MOVE EAST INTO CENTRAL AND NORTH
CENTRAL SOUTH DAKOTA THROUGH THE EVENING. THE HRRR MODEL SHOWS
THIS DEVELOPMENT VERY WELL. AS THE LLJ INCREASES INTO THE EVENING
HOURS...EXPECT THIS TREND TO CONTINUE. WITH INSTABILITY INCREASING
ALONG WITH DEEP LAYER SHEAR...SOME SEVERE STORMS ARE POSSIBLE
MAINLY WEST OF THE JAMES VALLEY TONIGHT. THIS FIRST WAVE WILL MOVE
THROUGH WITH MORE DEVELOPMENT EXPECTED SATURDAY AFTERNOON AND
EVENING ACROSS THE CWA. HIGH INSTABILITY WILL BUILD UP AGAIN
SATURDAY AFTERNOON AND EVENING ACROSS THE CWA WHILE ANOTHER SHORT
WAVE TROUGH KICKS OUT OF THE SOUTHWEST UPPER TROUGH. THIS
INTERACTION ALONG A GOOD LOW LEVEL SURFACE BOUNDARY/WARM FRONT ON
SATURDAY AFTERNOON AND EVENING WILL RESULT IN NUMEROUS SHOWERS AND
THUNDERSTORMS AGAIN. SEVERE STORMS LOOK LIKE A GOOD POSSIBILITY
ON SATURDAY AFTERNOON AND EVENING. AS THE MAIN UPPER LEVEL TROUGH
LIFTS INTO THE REGION SUNDAY AND SUNDAY NIGHT AND CLOSES
OFF...SHOWER AND THUNDERSTORM POSSIBILITIES WILL CONTINUE TO BE
VERY GOOD ACROSS ALL OF THE CWA. HEAVY RAIN WILL ALSO BE A THREAT
ACROSS THE CWA AS HIGH PRECIPITABLE WATERS WILL BE AVAILABLE FOR
STORMS.

.LONG TERM...MONDAY THROUGH FRIDAY

DECENT AGREEMENT EXISTS BETWEEN DETERMINISTIC GUIDANCE TO START
THINGS OFF WITH A NEARLY STATIONARY UPPER LOW OVER THE EASTERN
DAKOTAS/MINNESOTA. THIS FEATURE WILL DRIFT SLOWLY TO THE
EAST...WITH WRAP AROUND MOISTURE AND WEAK INSTABILITY LEADING TO
CONSTANT WIDESPREAD SHOWER ACTIVITY...WHICH WILL ALSO RESULT IN
TEMPERATURES BELOW NORMAL FOR MUCH OF THE EXTENDED. ONCE THE UPPER
LOW PUSHES EAST...A COL AREA FORMS OVERHEAD...WITH WEAK
SOUTHEASTERLY LOW LEVEL RETURN FLOW DEVELOPING FOR THE END OF THE
PERIOD...WITH MILDER TEMPERATURES AND LIKELY DRY CONDITIONS.



&&

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

VFR CONDITIONS FOR KABR/KMBG...WITH KATY/KPIR MIXING OUT MVFR
CIGS BY THE EARLY AFTERNOON. A FEW WEAK SHOWERS COULD
DEVELOPS AT KABR/KATY THIS AFTERNOON WITH NEGLIGIBLE EFFECT. MAIN
THREAT WILL BE STORMS PUSHING INTO THE KPIR/KMBG TERMINALS DURING
THE EVENING. THIS AREA OF CONVECTION WILL THEN POSSIBLY IMPACT
KABR/KATY TERMINALS OVERNIGHT. THERE IS THE POSSIBILITY THAT
CONVECTION WILL LEAVE US WITH MVFR CIGS BY THE MORNING...THOUGH
WITH LOW FORECASTER CONFIDENCE. WINDS WILL BE OUT OF THE
EAST/SOUTHEAST...BUT WILL INCREASE IN INTENSITY SOMEWHAT AS THEY
SHIFT TO DUE SOUTH EARLY SATURDAY.


&&

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

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

WEATHER.GOV/ABERDEEN