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000
FXUS64 KOHX 221040
AFDOHX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NASHVILLE TN
540 AM CDT WED MAY 22 2013

.UPDATE...

12Z TAF DISCUSSION.

&&

.AVIATION...

RADAR IMAGERY SHOWS MOST RECENT MCS HAS COLLAPSED WITH JUST A FEW
REMAINING -TSRA APPROACHING CSV. BY 12Z TAF ISSUANCE TIME...ALL
PRECIP SHOULD BE EAST OF AIRPORTS WITH DRY AND VFR CONDITIONS
EXPECTED THROUGH THE MORNING. LAMP GUIDANCE INDICATES GUSTY
SOUTHWEST WINDS TODAY WITH SPEEDS 5-12 KTS AND GUSTS TO 15-25
KTS. SHORTWAVE TROUGH ON WATER VAPOR IMAGERY OVER OKLAHOMA WILL
SWING ACROSS THE REGION LATER TODAY PRODUCING ANOTHER ROUND OF
SHOWERS AND STORMS IN THE AFTERNOON. DUE TO UNCERTAINTY ON
COVERAGE WILL ONLY MENTION VCTS AT CKV/BNA BUT TEMPO -TSRA AT
CSV. MUCH DRIER AIR ALOFT WILL FILTER IN BY 23/00Z WITH LESS
CLOUD COVER AND SOME PATCHY FOG POSSIBLE LATE IN TAF PERIOD.

55

&&

.PREV DISCUSSION... /ISSUED 246 AM CDT WED MAY 22 2013/

DISCUSSION...
CURRENT SETUP...UPPER TROUGH TAKING ON NEGATIVE TILT THROUGH THE MID-
LEVELS BASED ON LATEST RUC WITH THE COLDER AIR ALOFT REMAINING
BACK OVER CENTRAL PLAINS NOSING DOWN INTO ARKANSAS. A 35 TO 40
KNOT LOW LEVEL JET WAS CONTINUING TO FEED MOIST PLUME INTO MIDDLE
TENNESSEE. WIND FIELD LOOKS TO BE UNIDIRECTIONAL WITH SPEED SHEAR IN
THE LOWER TROPOSPHERE. UPPER LEVEL JET JUST RUNNING NORTH TO SOUTH
FROM ABOUT TEXARKANA NORTHWARD INTO IOWA WITH A 65 KNOT MID LEVEL
JET CUTTING ACROSS CENTRAL ARKANSAS. ON-GOING CONVECTION CURRENTLY
ACROSS FAR WESTERN KENTUCKY...WESTERN TENNESSEE AND DOWN THROUGH
MISSISSIPPI...BEEN SHOWING SIGNS OF WEAKENING LAST COUPLE OF HOURS
AS CLOUD TOPS CONTINUE TO WARM.

WITH THE CURRENT SETUP LOOKS LIKE SHOWERS AND STORMS WILL BE
LIKELY DURING THE DAY...WITH A FEW STRONG TO SEVERE STORMS
POSSIBLE...ESPECIALLY MID-DAY THROUGH THE AFTERNOON AND INTO THE
EARLY EVENING HOURS. THINK THE MAIN THREAT WILL BE DAMAGING WINDS AND
LARGE HAIL BUT ISOLATED TORNADOES ARE ALSO POSSIBLE. EVEN THOUGH
THE WIND FIELDS ARE UNIDIRECTIONAL THE SWEAT INDEX CLIMBS TO 362
AT 18Z AND 413 BY 00Z WITH MID-LEVEL DRYING IN PLACE DURING THE
MID-DAY THROUGH THE AFTERNOON/EARLY EVENING.

ON THURSDAY A SHORT WAVE ON THE BACK SIDE OF UPPER TROUGH WILL
DROP DOWN THROUGH THE OHIO VALLEY AND BRING A CHANCE FOR SHOWERS
AND ISOLATED THUNDERSTORMS MAINLY TO THE NORTHEAST HALF DURING THE
AFTERNOON WITH A SLIGHT CHANCE REMAINING ALONG THE PLATEAU
THURSDAY NIGHT. MUCH OF THE MEMORIAL DAY WEEKEND LOOKS DRY HOWEVER
MODELS HAVE BEEN DIFFERING. GFS HAS WARM FRONT DRAPED ACROSS THE
OHIO VALLEY THROUGH THE WEEKEND WHICH WOULD KEEP MID STATE
BASICALLY WARM AND DRY. THE EURO HAS WARM FRONT DRAPED THROUGH
WESTERN TENNESSEE INTO NORTHERN ALABAMA AND KEEPS SHOWERS AND
STORMS IN THE MID STATE JUST ABOUT EACH DAY THROUGH THE MEMORIAL
DAY WEEKEND. HAVE OPTED TO GO WITH GFS FOR THIS FORECAST PACKAGE.

HAVE BACKED OFF A TAD FROM MAV MOS ON HIGHS TODAY AND WENT CLOSER
TO THE MET DUE TO CLOUD COVER AND SHOWER/STORM CHANCES. STAYED
CLOSE TO MOS GUIDANCE THROUGH REMAINDER OF FORECAST.

BOYD

&&

.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$