Severe Thunderstorm Warning 494, NWS Memphis, TN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEMPHIS TN
250 AM CST WED NOV 15 2006

.DISCUSSION...

UPPER LOW IS DEVELOPING OVER OKLAHOMA. A SURFACE LOW HAS NOW
FORMED AND AS OF 08Z IS OVER SOUTHEASTERN OKLAHOMA. THERE ARE
THREE SURFACE BOUNDARIES OF INTEREST. THE FIRST IS A WIND SHIFT
LINE THAT EXTENDS ROUGHLY ALONG INTERSTATE 40. THIS WIND SHIFT IS
ASSOCIATED WITH THE CURRENT WEST/EAST ORIENTED CONVECTION THAT HAS
BEEN ONGOING ACROSS THE REGION. THE SECOND BOUNDARY IS THE PRIMARY
WARM FRONT THAT EXTENDS SOUTHEAST FROM THE SURFACE LOW ACROSS
SOUTHERN ARKANSAS AND TO NEAR THE JACKSON MS AREA. THIS WARM FRONT
IS EXPECTED TO SURGE NORTHWARD AND BY 15Z BE ORIENTED ACROSS NORTH
MS. THE AIRMASS BEHIND THIS FRONT IS EXTREMELY MOIST AND UNSTABLE.
THE THIRD SURFACE FEATURE IS THE COLD FRONT WHICH IS MOVING ACROSS
EAST TEXAS. THIS FRONT WILL BE MOVING ACROSS NORTH MS TODAY. THE
CONVECTION OF INTEREST IS EXPECTED TO BEGIN TO DEVELOP SHORTLY
(BETWEEN 09Z AND 12Z) AS A LINE OF THUNDERSTORMS AHEAD OF THE FRONT
FROM SOUTHERN ARKANSAS THROUGH LOUISIANA. BETWEEN 12Z AND
15Z...THIS LINE WILL BE CROSSING THE MISSISSIPPI RIVER AND SHOULD
BE GROWING NORTHWARD AS THE WARM FRONT MOVES INTO NORTH
MISSISSIPPI. BETWEEN 15 AND 18Z...THE WARM FRONT WILL BE ALONG
INTERSTATE 40 WHILE THE LINE OF THUNDERSTORMS AHEAD OF THE COLD
FRONT IS ROUGHLY FROM PICKWICK LAKE THROUGH THE ENTIRE STATE OF
MS. THE STORM PREDICTION CENTERS DAY ONE OUTLOOK HAS A VERY GOOD
HANDLE ON THE HAZARDOUS WEATHER POTENTIAL ACROSS THE FORECAST
AREA. THE MAIN AREA OF CONCERN FOR TODAY IS ROUGHLY FROM AMORY TO
CLARKSDALE. THIS IS WHERE THE BIGGER THUNDERSTORMS...AND POSSIBLY
TORNADIC ARE LIKELY TO OCCUR. NORTH OF THIS LINE...IN THE SLIGHT
RISK AREA THE TORNADIC POTENTIAL WILL DEPEND UPON JUST HOW FAR
NORTH THE WARM FRONT SURGES AS THE CONVECTIVE LINE MOVES THROUGH
THE REGION. AS THE SLIGHT RISK MOVES TOWARDS THE TN/MS
BORDER...THE THREAT IS MUCH MORE OF A LARGE HAIL THREAT FROM
ELEVATED THUNDERSTORMS THAN A TORNADO THREAT AS THE CONVECTIVE
LINE WILL LIKELY BE IN ALABAMA BY THE TIME THE WARM FRONT GETS
INTO TN.

A FEW BREAKS IN THE CLOUDS ARE POSSIBLE THIS AFTERNOON BEHIND THE
FRONT...ESPECIALLY ACROSS NORTH MS AS THE DRY PUNCH WORKS INTO THE
REGION. BY TONIGHT...RAIN WILL WORK BACK IN AS THE UPPER LOW MOVES
THROUGH THE REGION. LATEST MODEL RUNS SLOW DOWN THE PROGRESSION OF
THE UPPER LOW AND IT IS A TAD FURTHER SOUTH. MODELS INDICATE A
GOOD DEAL OF MOISTURE WRAPPED AROUND IT. AS A RESULT...FEEL VERY
CONFIDENT THAT MOST IF NOT ENTIRE FORECAST AREA WILL SEE RAIN
TONIGHT ALTHOUGH AMOUNTS MAY NOT BE ALL THAT MUCH.

RAIN/CLOUDS WILL LIKELY LINGER INTO TOMORROW AND HAVE RAISED RAIN
CHANCES AND LOWERED TEMPERATURES AS A RESULT. SOME AREAS OF WEST
TENNESSEE MAY NOT SEE TEMPS CLIMB OUT OF THE LOW 40S. HAVE LOOKED
AT SOUNDINGS AND MELTING HEIGHTS ARE STILL AROUND OR ABOVE 2000 FT
ACROSS THE ENTIRE REGION AND SO AM NOT INCLINED TO MENTION MIXED
PRECIP.

RAIN SHOULD BE MOVING OUT BY TOMORROW NIGHT. AS THE LOW CLOUDS
MOVE OUT...HIGH AND MID LEVEL CLOUDS ASSOCIATED WITH A WEAK UPPER
SHORTWAVE WILL BE MOVING THROUGH THURSDAY NIGHT AND FRIDAY. FRIDAY
NIGHT/SATURDAY A WEAK COLD FRONT WILL PASS THROUGH THE REGION.
LIFT IS VERY WEAK AND LITTLE MOISTURE AROUND SO EXPECT IT TO PASS
THROUGH DRY. ANOTHER WEAK UPPER SHORTWAVE WILL MOVE THROUGH SUNDAY
BUT THERE IS NO SURFACE FEATURE AND BY ITSELF IT DOES NOT APPEAR
STRONG ENOUGH FOR RAIN CHANCES. DRY WEATHER SHOULD THEN PERSIST
THROUGH THE REMAINDER OF THE FORECAST.

&&

.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&

VALLE

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE MEMPHIS TN
341 AM CST WED NOV 15 2006

ARZ008-009-017-018-026>028-035-036-048-049-058-MOZ113-115-
MSZ001>017-020>024-TNZ001>004-019>021-048>055-088>092-161145-
ALCORN-BENTON(MS)-CALHOUN-CARROLL-CHESTER-CHICKASAW-CLAY-COAHOMA-
CRAIGHEAD-CRITTENDEN-CROCKETT-CROSS-DESOTO-DECATUR-DUNKLIN-DYER-
FAYETTE-GIBSON-GREENE-HARDEMAN-HARDIN-HAYWOOD-HENDERSON-HENRY-
ITAWAMBA-LAFAYETTE-LAKE-LAUDERDALE-LAWRENCE-LEE(AR)-LEE(MS)-
MADISON-MARSHALL-MCNAIRY-MISSISSIPPI-MONROE-OBION-PANOLA-PEMISCOT-
PHILLIPS-POINSETT-PONTOTOC-PRENTISS-QUITMAN-RANDOLPH-SHELBY-
ST. FRANCIS-TALLAHATCHIE-TATE-TIPPAH-TIPTON-TISHOMINGO-TUNICA-
UNION-WEAKLEY-YALOBUSHA-
341 AM CST WED NOV 15 2006

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF EAST ARKANSAS...
THE MISSOURI BOOTHEEL...NORTH MISSISSIPPI...AND WEST TENNESSEE.

.DAY ONE...TODAY AND TONIGHT

THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS ALONG AND SOUTH
OF A LINE FROM CLARKSDALE MISSISSIPPI TO AMORY MISSISSIPPI. THERE
IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ALONG AND SOUTH OF
INTERSTATE 40. AN INTENSE LOW PRESSURE SYSTEM IS EXPECTED TO MOVE
INTO THE AREA TODAY. A WARM FRONT WILL RISE TO NEAR INTERSTATE 40
BY LATE MORNING. THE AIR SOUTH OF THE WARM FRONT WILL BE VERY
MOIST AND UNSTABLE. IN ADDITION...A COLD FRONT IS EXPECTED TO
SWEEP ACROSS NORTH MISSISSIPPI THIS MORNING. A LINE OF
THUNDERSTORMS IS EXPECTED TO DEVELOP IN ADVANCE OF THE FRONT AND
MOVE THROUGH THE SLIGHT AND MODERATE RISK AREA THIS MORNING. IN
THE SLIGHT RISK AREA...THE SEVERE WEATHER THREAT IS MAINLY LARGE
HAIL AND LOCALLY DAMAGING WINDS. IN THE MODERATE RISK AREA...AN
ISOLATED TORNADO CAN NOT BE RULED OUT.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY

NO HAZARDOUS WEATHER IS EXPECTED.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS LIKELY TODAY.

VALLE