000
FXUS63 KABR 151613 AAA
AFDABR

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE ABERDEEN SD
1113 AM CDT WED MAY 15 2013

.UPDATE...
CURRENT RADAR IMAGERY SHOWS ISOLATED SHOWERS EXTENDING FROM EAST
CENTRAL SOUTH DAKOTA THROUGH SOUTHWEST NORTH DAKOTA. WHILE LITTLE
IN THE WAY OF ADDITIONAL ACCUMULATION TODAY...THE HRRR MODEL HAS
PICKED UP ON THIS VERY WELL AND DOES INDICATE THAT ISOLATED
SHOWERS OR THUNDERSTORMS WILL LINGER ACROSS THE NORTHERN/EASTERN
CWA THIS AFTERNOON. THEREFORE...DID ADD A 20 POP FOR ISOLATED
SHOWERS AND THUNDERSTORMS. THE ONLY OTHER MINOR CHANGE TO THE
FORECAST WAS TO KNOCK DOWN TEMPERATURES A FEW DEGREES UNDER THE
THICKEST CLOUD COVER. WHILE THE CLOUDS ARE EXPECTED TO BREAK APART
THIS AFTERNOON...ITS GOING TO TAKE AWHILE FOR IT TO HAPPEN ACROSS
THE CENTRAL CWA...AND THEREFORE LIMIT SOME OF THE DAYTIME HEATING.

&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TODAY THROUGH FRIDAY
PRECIPITATION CHANCES THROUGHOUT THE PERIOD WILL BE THE MAIN
FORECAST CHALLENGE.

SHOWERS AND THUNDERSTORMS ARE CURRENTLY MOVING ACROSS THE CWA THIS
MORNING. RIGHT ENTRANCE REGION OF AN UPPER LEVEL JET ALONG WITH A
WEAK SHORT WAVE TROUGH WILL LIKELY CONTINUE TO PRODUCE THESE LIGHT
SHOWERS THROUGH THE MID MORNING HOURS BEFORE DIMINISHING. THE
LOWER LEVELS ARE RATHER DRY SO WOULD NOT EXPECT A GREAT DEAL OF
MOISTURE REACHING THE GROUND. THIS AFTERNOON AND A BETTER PORTION
OF TONIGHT WILL BE DRY UNTIL THE NEXT SYSTEM MOVES ACROSS THE
REGION LATE TONIGHT THROUGH THURSDAY. THIS STORM SYSTEM APPEARS TO
SPLIT IN TWO WITH THE NORTHERN PORTION TRACKING ACROSS NORTH DAKOTA
AND THE SOUTHERN PORTION MOVING ALONG AND SOUTH OF I-90.

THURSDAY NIGHT LOOKS LIKE THE BEST TIME PERIOD FOR THE DEVELOPMENT
OF SHOWERS AND THUNDERSTORMS...ESPECIALLY FOR THE EASTERN CWA.
ADDITIONAL SHORT WAVE ACTIVITY WILL COMBINE WITH A 35 TO 40 KNOT
LLJ TO RESULT IN CONVECTIVE DEVELOPMENT. SEVERE THUNDERSTORMS DO
NOT APPEAR LIKELY...NEITHER DOES LOCALLY HEAVY RAINFALL.

ASIDE FROM LINGERING CONVECTION DURING THE MORNING HOURS...A
BETTER PORTION OF FRIDAY LOOKS DRY. MID LEVEL TEMPERATURES WILL
WARM THROUGH THE DAY WITH H7 TEMPS REACHING THE UPPER SINGLE
DIGITS. THESE WARM TEMPS SHOULD CAP CONVECTION UNTIL AFTER 00Z
SATURDAY OR JUST BEYOND THE SHORT TERM PORTION OF THE FORECAST.

.LONG TERM...FRIDAY NIGHT THROUGH TUESDAY
AN UPPER LEVEL RIDGE WILL EXIT THE REGION FRIDAY NIGHT AND
SATURDAY AHEAD OF AN APPROACHING TROUGH. SHORTWAVE ENERGY
ASSOCIATED WITH THE TROUGH WILL THEN AFFECT THE NORTHERN PLAINS
THROUGH THE END OF THE PERIOD. THE MODELS ARE IN DECENT AGREEMENT
WITH THE SURFACE PATTERN THROUGH THE DAY MONDAY...THEN BEGIN TO
DIVERGE SOME AS THE ECMWF BRINGS HIGH PRESSURE OVER THE AREA WHILE
THE GFS KEEPS THE LOW IN THE VICINITY LONGER. THERE IS SOME DECENT
INSTABILITY THAT SHOWS UP ACROSS THE WEST FRIDAY NIGHT...AND EVEN
BETTER INSTABILITY ACROSS THE CENTRAL AND EAST SATURDAY NIGHT.
EXPECT THERE COULD BE SOME STRONG TO SEVERE THUNDERSTORMS
SOMEWHERE IN THE AREA BOTH EVENINGS. CANNOT REALLY DISCERN ANY
TIME PERIOD WHEN IT WILL BE COMPLETELY DRY...SO WILL STICK CLOSE
TO ALLBLEND POPS...WHICH ARE GENERALLY IN THE SCHC TO HIGH CHC
CATEGORY THROUGHOUT THE PERIOD.

SATURDAY WILL BE THE WARMEST DAY OF THE PERIOD WITH HIGH
TEMPERATURES GENERALLY IN THE 70S. WILL THEN SEE A COOLING TREND
THROUGH THE REST OF THE PERIOD UNDER MOSTLY CLOUDY SKIES AND WITH
CHANCES OF PRECIPITATION. HIGHS WILL BE IN THE UPPER 60S TO LOWER
70S ON SUNDAY...THEN MAINLY IN THE 60S MONDAY AND TUESDAY.

&&

.AVIATION...
12Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS

AN AREA OF SHOWERS AND WEAK THUNDERSTORMS WILL TRACK ACROSS THE
SOUTHERN HALF OF THE CWA THROUGH THE MORNING HOURS...AFFECTING
KPIR AND KATY. CIGS WILL REMAIN VFR WITH THE PRECIPITATION...BUT
VSBYS MAY BRIEFLY FALL INTO THE MVFR CATEGORY WITH THE
THUNDERSTORMS. THE PRECIPITATION SHOULD EXIT THE AREA BY EARLY
AFTERNOON...THEN VFR CONDITIONS WILL PREVAIL THROUGH THE REMAINDER
OF THE TAF PERIOD.

&&

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

$$
UPDATE...SERR
SHORT TERM...SD
LONG TERM...PARKIN
AVIATION...PARKIN

WEATHER.GOV/ABERDEEN