000
FXUS63 KABR 152323 AAA
AFDABR

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE ABERDEEN SD
623 PM CDT WED MAY 15 2013

.UPDATE...
THE AVIATION DISCUSSION HAS BEEN UPDATED FOR THE 00Z TAF ISSUANCE.

&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TONIGHT THROUGH SATURDAY MORNING
LIGHT RAIN SHOWERS/SPRINKLES CONTINUE ACROSS PARTS OF NORTH
CENTRAL AND NORTHEAST SOUTH DAKOTA. THESE SHOWERS SEEM TO BE WELL
CORRELATED WITH AN AREA OF WEAK MODEL DEPICTED 700 MB
FRONTOGENESIS. SHOWERS ARE EXPECTED TO DISSIPATE LATER THIS
AFTERNOON OR EARLY EVENING.

TONIGHT SHOULD BE MILD...WITH A WEAK AREA OF SURFACE HIGH PRESSURE
OVER THE NORTHERN PLAINS. TEMPERATURES WILL LIKELY DROP INTO THE
MID 40 TO LOW 50S UNDER CLEAR SKIES. WINDS WILL SWITCH BACK TO
THE SOUTH SOUTHEAST AS ANOTHER AREA OF LOW PRESSURE DEVELOPS
FURTHER TO THE WEST.

SHORTWAVE ENERGY WILL MOVE ACROSS THE REGION ON
THURSDAY...DEVELOPING SHOWERS AND THUNDERSTORMS EARLY THURSDAY
MORNING ACROSS THE WESTERN CWA AND PROPAGATING EASTWARD THROUGHOUT
THE AFTERNOON. EXPECTING MAINLY RAIN SHOWERS...BUT WITH VERY
LIMITED CAPE /50 TO 100 J/KG/ THERE MAY ALSO BE A RUMBLE OF
THUNDER. MODELS ARE SUGGESTING A LLJ WILL SET UP LATE THURSDAY
NIGHT/FRIDAY MORNING...HELPING TO CONTINUE PRECIPITATION THROUGH
THE NIGHT. MODELS ARE STILL UNCERTAIN IN THE EXACT PLACEMENT OF
THE LLJ...BUT ARE ALL SHOWING AT LEAST A 20 TO 30 KT LLJ SETTING
UP SOMEWHERE ACROSS THE CWA. THERE MAY BE SOME LINGERING
PRECIPITATION INTO FRIDAY MORNING BEFORE THE SHORTWAVE MOVES EAST
OF THE AREA.

BY FRIDAY...THE SURFACE LOW WILL BE MOVING EASTWARD...ALLOWING
GULF MOISTURE TO BE PULLED NORTHWARD. MODELS ARE SHOWING SURFACE
DEWPOINTS FROM THE UPPER 50 TO LOW 60S SPREADING ACROSS THE CWA.
LIKEWISE...ML CAPE VALUES WILL RISE INTO THE 2000 TO 3000 J/KG
RANGE ACROSS THE SOUTHERN HALF OF THE CWA BY FRIDAY AFTERNOON.
MODELS ARE ALSO SUGGESTING ANYWHERE FROM 30 TO 60 KTS OF 0-6 KM
SHEAR. THIS SETUP WILL PROVIDE A VERY GOOD ENVIRONMENT FOR STRONG
THUNDERSTORM DEVELOPMENT...HOWEVER...THE LIMITING FACTORS ON
FRIDAY AFTERNOON MAY BE THE LIMITED UPPER LEVEL FORCING...AS WELL
AS ANY LEFT OVER STRATUS FROM THE SHOWERS THAT ARE EXITING THE
AREA ON FRIDAY MORNING. THESE FACTORS COULD LIMIT HOW SOON
THUNDERSTORMS DEVELOP. HOWEVER..THERE WILL BE ANOTHER LLJ JET THAT
SETS UP FRIDAY NIGHT/SATURDAY MORNING. MODELS ARE SHOWING A 40 KT
LLJ NOSING INTO THE SOUTHERN CWA...AND THEN MOVING EASTWARD
OVERNIGHT. SO...IF CONVECTION DOESNT GET GOING PRIOR TO THE LLJ
DEVELOPMENT...IT CERTAINLY SHOULD LATE FRIDAY INTO SATURDAY MORNING.

.LONG TERM...SATURDAY THROUGH WEDNESDAY
THE GFS ENSEMBLES AND OPERATIONAL MODELS ALL SHOW VERY GOOD
AGREEMENT IN THE LONG TERM WITH THE MAIN WEATHER FEATURE TO AFFECT
OUR REGION. THE LONG TERM BEGINS WITH A LARGE NEGATIVE TILT UPPER
LEVEL LOW PRESSURE TROUGH IN THE SOUTHWEST US. THIS LIFTS SLOWLY
NORTHEAST INTO THE CENTRAL AND NORTHERN PLAINS THROUGH SUNDAY
NIGHT AND CLOSES OFF. THEN THIS LARGE CLOSED LOW PRESSURE AREA
REMAINS NEARLY STATIONARY THROUGH MONDAY AND TUESDAY AND MAYBE
MOVES EAST ON TUESDAY NIGHT AND WEDNESDAY. WITH THIS SETUP...MOST
OF THE LONG TERM WILL HAVE GOOD CHANCES OF SHOWERS AND
THUNDERSTORMS ACROSS ALL OF THE CWA. WITH PLENTY OF GULF MOISTURE
AROUND...THERE COULD BE SOME DECENT RAINS WHEN IT IS ALL SAID AND
DONE. SATURDAY AND SATURDAY EVENING COULD ALSO BRING SOME SEVERE
WEATHER WITH A GOOD WARM FRONT SURGING NORTHWARD ALONG WITH AN
INCREASING 85H LLJ. HIGH TEMPERATURES WILL EASILY MAKE IT INTO THE
UPPER 70S TO THE LOWER 80S ACROSS THE CWA WITH AMPLE INSTABILITY
AND MOISTURE AROUND. OTHERWISE...WITH THE UPPER LOW PRESSURE AREA
CLOSING OFF OVER THE REGION ALONG WITH COOLER AIR ADVECTING IN
AND WITH CLOUD COVER AND SHOWERS AND THUNDERSTORMS...SUNDAY WILL
COOL OFF SOME. THE COOLER AIR WILL REMAIN THROUGH WEDNESDAY WITH
HIGHS MAINLY IN THE 60S FOR MONDAY THROUGH WEDNESDAY. INCREASED
POPS THROUGH MOST OF THE PERIOD.

&&

.AVIATION...
00Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS

VFR CONDITIONS ARE EXPECTED AT ALL TERMINALS THROUGH TONIGHT. SOME
SHOWERS WILL MOVE FROM WEST TO EAST ACROSS THE REGION ON
THURSDAY.

&&

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

&&

$$
UPDATE...TDK
SHORT TERM...SERR
LONG TERM...MOHR
AVIATION...TDK

WEATHER.GOV/ABERDEEN