Severe Thunderstorm Warning 1, NWS Memphis, TN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEMPHIS TN
809 PM CST THU JAN 12 2006

.UPDATE...

CURRENT FORECAST IS IN GOOD SHAPE. HOWEVER...MAIN CONCERN THIS
EVENING IS WHETHER WE WILL HAVE ANY SEVERE THUNDERSTORMS IN OUR
FORECAST AREA OVERNIGHT.

DRY LINE EXTENDS FROM SOUTHWEST MO THROUGH EASTERN OK INTO CENTRAL
TX THIS EVENING. DEWPOINTS ARE IN THE LOWER AND MIDDLE 50S IN
EASTERN OK AHEAD OF THE DRY LINE AND IN THE 30S IN WESTERN OK. A
COLD FRONT IS GRADUALLY MERGING WITH THE DRY LINE FROM THE WEST.
LATEST RADARS AND LIGHTNING DETECTION NETWORK INDICATE A NARROW
BAND OF THUNDERSTORMS HAS ERUPTED JUST AHEAD OF THE DRY LINE. 00Z
LITTLE ROCK SOUNDING INDICATED A STRONG CAP AROUND 830 MB. THINK
THIS CAP WILL BREAK WITH LARGE SCALE ASCENT FROM AN APPROACHING
UPPER LEVEL TROUGH. THIS WILL ALLOW THUNDERSTORMS TO MOVE INTO THE
MID-SOUTH AHEAD OF THE COLD FRONT / DRY LINE AFTER MIDNIGHT.
POTENTIAL CAPES...ONCE THE CAP IS BROKEN...ARE INDICATED BY THE
LITTLE ROCK SOUNDING TO BE AROUND 1200 J/KG. WILL UPDATE THE
HAZARDOUS WEATHER OUTLOOK TO MENTION THAT A FEW SEVERE THUNDERSTORMS
COULD BE SEVERE OVERNIGHT ACROSS THE MO BOOTHEEL AND EASTERN AR.
SHEAR IS NO PROBLEM AS 0-3 KM HELICITY WAS 469 ON THE LITTLE ROCK
SOUNDING...BUT LOW LEVEL MOISTURE MAY BE A LIMITING FACTOR. SOUTHEAST
SURFACE WINDS ARE PRESENTLY PUSHING DEWPOINTS INTO THE 40S ACROSS
MUCH OF THE MID-SOUTH. HOWEVER...WITH THE APPROACH OF THE
FRONT...SURFACE WINDS WILL TURN MORE TO THE SOUTHWEST ALLOWING A
NARROW BAND OF DEWPOINTS IN THE 50S JUST AHEAD OF THE FRONT. FOR
NOW...WILL HOLD OFF ON MENTIONING THE THREAT OF SEVERE EAST OF THE
MS RIVER...SINCE THE THUNDERSTORMS WILL BE ARRIVING IN THIS AREA
LATE TONIGHT...A LESS FAVORABLE TIME DIURNALLY FOR SEVERE.

&&

.PREV DISCUSSION... (ISSUED 253 PM CST THU JAN 12 2006)

DISCUSSION...

CURRENTLY...GOOD DEAL OF LOW CLOUD COVER HAS MOVED INTO THE MID
SOUTH TODAY. AS A RESULT HIGH TEMPS HAVE NOT LIVED UP TO THEIR
POTENTIAL...HOWEVER THEY ARE STILL RUNNING ABOUT 10 DEGREES ABOVE
NORMAL AT MOST PLACES.

TONIGHT...STRONG UPPER TROF CURRENTLY MOVING INTO THE CNTRL/SRN
PLAINS THIS AFTERNOON WL MOVE INTO THE MID SOUTH LATER TONIGHT AS
A SURFACE LOW TRACKS FROM THE OK/KS BORDER ACROSS MO INTO THE MID
MS VALLEY. THE ASSOCD COLD FRONT MOVING INTO EASTERN AR SHORTLY
AFTER MIDNIGHT...ACROSS THE MS RIVER AROUND 11Z...AND OUT OF THE
FORECAST AREA BY 14Z. PREFER THE SLIGHTLY FASTER GFS FOR THIS
FORECAST. ACCORDING TO HPC THE NAM INITIALIZED UPPER TROF RATHER
POORLY OVER THE ROCKIES WITH THE GFS HANDLING THE TROF SLIGHTLY
BETTER.

SHOWERS AND THUNDERSTORMS WILL BEGIN TO DEVELOP ALONG AND IN
ADVANCE OF THE FRONT THIS EVENING AS THE UPPER TROF APPROACHES AND
LARGE SCALE ASCENT INCREASES MOVES OVER THE REGION. SEVERE
POTENTIAL REMAINS RATHER UNIMPRESSIVE. INSTABILITY CONTINUES TO
LOOK MARGINAL DUE TO LACK OF LOW LEVEL MOISTURE. NEAREST 60
DEGREE DEWPOINT OVER SE TX ATTM. MODELS ARE FORECASTING MID TO
MAYBE UPPER 50S DEWPOINTS MOVING NORTH IN ADVANCE OF THE FRONT.
AS A RESULT SURFACE BASED INSTABILITY WL BE PRACTICALLY NON-
EXISTENT. DUE TO THE UPPER TROF MOVING INTO THE REGION MID LEVEL
TEMPS WL COOL CONSIDERABLY HELPING TO CREATE SOME INSTABILITY
ABOVE THE BOUNDARY LAYER. MU CAPES MAY REACH 500-800 J/KG. PERHAPS
SOME STORMS WL UTILIZE THIS AVAILABLE CAPE TO PRODUCE SOME SMALL
HAIL.

FRIDAY...FRONT WILL EXIT THE MID SOUTH EARLY IN THE MORNING. THE
UPPER LOW IS DEEPER WITH THE 12Z MODEL RUN SO EXPECT LOTS OF WRAP
AROUND LOW CLOUDS AND SOME LIGHT RAIN/DRIZZLE BEHIND THE FRONT.
TEMPS WL PROBABLY NOT GO ANYWHERE BUT SOUTH TOMORROW DUE TO STRONG
LOW LEVEL COLD AIR ADVECTION AND PLENTY OF CLOUD COVER. SURFACE
WINDS WL BE QUITE STRONG AS WELL MAKING FOR A COOL...BLUSTERY AND
DAMP DAY.

FRIDAY NIGHT...UPPER TROF MOVES FROM WRN KY INTO ERN TN FRIDAY
NIGHT. AREA STILL UNDER CYCLONIC FLOW DURING THE EVENING AND
MODELS ARE HINTING AT SOME PRECIP ACRS MAINLY W TN. MODEL
SOUNDINGS INDICATING THE POSSIBILITY OF A RAIN/SNOW MIX ACRS NE
SECTIONS OF THE FORECAST AREA AND HAVE DECIDED TO INCLUDE THIS
DURING THE EVENING. AFTER MIDNIGHT SKIES WERE BEGIN TO CLEAR AS
TROF LIFTS AWAY AND HIGH PRESSURE STARTS TO MOVE IN.

SATURDAY THROUGH SUNDAY...HIGH PRESSURE WL BE OVER THE AREA ON
SATURDAY RESULTING IN SUNSHINE AND NEAR NORMAL TEMPS. HIGH SLIPS
EAST ON SUNDAY AND RETURN FLOW RESTARTS AND ABOVE NORMAL TEMPS
RETURN.

EXTENDED...NEXT SYSTEM IMPACTS THE REGION. STRONG UPPER TROF WL
MOVE THROUGH THE REGION DURING THE BEGINNING OF THE WEEK. EXPECT
MORE MILD WEATHER EARLY IN THE WEEK WITH BEST CHANCE OF RAIN
MONDAY AND MONDAY NIGHT. HIGH PRESSURE BUILDS IN FOR MID WEEK.

&&

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

JCL/SJM

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE MEMPHIS TN
1201 AM CST FRI JAN 13 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>092-131100-
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-
1201 AM CST FRI JAN 13 2006

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

.DAY ONE...TONIGHT

THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS TONIGHT ACROSS THE
MISSOURI BOOTHEEL AND EASTERN ARKANSAS.

A COLD FRONT WILL MOVE INTO THE MID-SOUTH AFTER MIDNIGHT PRECEDED
BY A LINE OF THUNDERSTORMS. A FEW OF THE THUNDERSTORMS MAY BE
SEVERE WEST OF THE MISSISSIPPI RIVER WITH LARGE HAIL AND DAMAGING
WINDS BEING THE MAIN THREATS. AN ISOLATED TORNADO IS ALSO POSSIBLE.
ELSEWHERE...ACROSS WEST TENNESSEE AND NORTH MISSISSIPPI...A FEW
STRONG THUNDERSTORMS ARE POSSIBLE WITH GUSTY WINDS AND SMALL HAIL.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

THE PROBABILITY OF WIDESPREAD HAZARDOUS WEATHER IS LOW.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE NEEDED TONIGHT.

JCL