Severe Thunderstorm Warning 283, NWS Nashville, TN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NASHVILLE TN
122 PM CDT TUE AUG 4 2009

.AVIATION...CONVECTION IS FIRING ALONG THE CUMBERLAND PLATEAU,
WITH A HIGHLY UNSTABLE ENVIRONMENT IN PLACE ACROSS MIDDLE
TENNESSEE TODAY. MAY SEE SOME CONVECTION AT BNA/CSV DURING THE
AFTERNOON, BUT ESPECIALLY OVERNIGHT AS A COLD FRONT MAKES ITS WAY
ACROSS THE MID STATE.

&&

.PREV DISCUSSION... /ISSUED 1037 AM CDT TUE AUG 4 2009/

UPDATE...IT WAS MOSTLY SUNNY AND WARM ACROSS THE MID STATE THIS
MORNING, WITH TEMPERATURES CLIMBING OUT OF THE 70S AND THROUGH THE
80S.

THE FORECAST PROBLEM FOR TODAY CONSISTS OF SEVERAL PARTS. FIRST,
WHICH AREAS WILL SEE THE BEST CHANCE FOR AFTERNOON THUNDERSTORMS
AND HOW HOT WILL IT GET? THE 12Z OHX SOUNDING SHOWED A LOT OF
AVAILABLE CAPE, BUT IT CAN ONLY BE TAPPED IF TEMPERATURES WARM
SUFFICIENTLY, ATMOSPHERIC MOISTURE DEEPENS, AND/OR A SOURCE OF
LIFT CAN HELP GIVE PARCELS THE UMPH THEY NEED. ONCE TEMPERATURES
GET AROUND 90, WE SHOULD HAVE SUFFICIENT BUOYANCY TO GET ISOLATED
TO SCATTERED CONVECTION. IF GFS AND NAM ARE CORRECT, ATMOSPHERIC
MOISTURE MAY DEEPEN OVER OUR NORTHERN COUNTIES LATE TODAY, THANKS
TO MCS DEBRIS DROPPING IN. THE LATEST RUC AND WRF, HOWEVER, KEEP
THINGS ABOUT THE SAME THROUGHOUT THE DAY. HAVE BEEN TRACKING A
SOUTHWESTWARD-PROPAGATING OUTFLOW BOUNDARY FROM THE SDF
CONVECTION INTO OUR CWA AND LATEST SATELLITE PIC SHOWED IT NEAR
BNA. ANOTHER ONE, IS SWINGING SOUTHEASTWARD TOWARD PAH. THIS
FEATURE COULD HELP PROVIDE SOME EXTRA LIFT DURING MAX HEATING.

EXPECT BEST CHANCE FOR THUNDERSTORMS TO BE IN THE NORTH, WHERE
ATMOSPHERIC MOISTURE MAY DEEPEN AND WILL BE MOST VULNERABLE TO THE
INTRUSION OF OUTLFOW BOUNDARIES FROM CONVECTION TO OUR NORTH.

WITH PROBABLY GO WITH A POP RANGE OF 50% IN THE NORTH TO 20% IN
THE EXTREME SOUTH.

MIGHT NUDGE MAX TEMPERATURES A LITTLE DEEPER INTO THE MIDDLE 90S
FOR SOME SOUTHERN AREAS, WHERE POPS ARE LOWEST. OTHERWISE, WILL
PROBABLY LEAVE CURRENT ZFP TEMP FORECAST AS IS.

&&

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

ROSE

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE NASHVILLE TN
1123 AM CDT TUE AUG 4 2009

TNZ005>011-022>034-056>066-075-077>080-093>095-051630-
STEWART-MONTGOMERY-ROBERTSON-SUMNER-MACON-CLAY-PICKETT-BENTON-
HOUSTON-HUMPHREYS-DICKSON-CHEATHAM-DAVIDSON-WILSON-TROUSDALE-
SMITH-JACKSON-PUTNAM-OVERTON-FENTRESS-PERRY-HICKMAN-LEWIS-
WILLIAMSON-MAURY-MARSHALL-RUTHERFORD-CANNON-DEKALB-WHITE-
CUMBERLAND-BEDFORD-COFFEE-WARREN-GRUNDY-VAN BUREN-WAYNE-LAWRENCE-
GILES-
1123 AM CDT TUE AUG 4 2009

THIS HAZARDOUS WEATHER OUTLOOK IS FOR MIDDLE TENNESSEE.

.DAY ONE...THIS AFTERNOON AND TONIGHT
SCATTERED THUNDERSTORMS ARE EXPECTED THIS AFTERNOON...A FEW OF
WHICH MAY PRODUCE DAMAGING WINDS...HAIL...AND TORRENTIAL DOWNPOURS.
THE BEST CHANCE FOR STORMS TODAY WILL BE ACROSS NORTHERN AREAS...
ESPECIALLY NEAR THE KENTUCKY BORDER..

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

A COLD FRONT IS EXPECTED TO PRODUCE THUNDERSTORMS IN THE MID STATE
TONIGHT AND WEDNESDAY...A FEW OF WHICH COULD BECOME STRONG TO
SEVERE...AND PRODUCE GUSTY WINDS...HAIL...AND BRIEF HEAVY
DOWNPOURS.

.SPOTTER INFORMATION STATEMENT...

DUE TO THE BRIEF AND ISOLATED NATURE OF THE POSSIBLE SEVERE
WEATHER... SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.

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