Severe Thunderstorm Warning 53, NWS Nashville, TN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NASHVILLE TN
417 AM CDT FRI APR 22 2005

.DISCUSSION...CURRENTLY, LINE OF CONVECTION MOVING ACROSS MIDDLE
TENNESSEE HAS WEAKENED CONSIDERABLY SINCE PRODUCING A HANDFUL OF
SEVERE STORMS WEST OF NASHVILLE. ROUND TWO IS MOVING IN ON THE MID
STATE FROM THE NORTHWEST, WITH A CONSIDERABLE AMOUNT OF ELECTRICAL
ACTIVITY. AT 08Z, A 1005 MB SURFACE LOW WAS SITUATED OVER NORTHEAST
MISSOURI, WITH A COLD FRONT TRAILING SOUTHWESTWARD FROM THE LOW
THROUGH THE OZARKS AND THE ARK-LA-TEX. CONVECTION CONTINUES TO
DEVELOP ALONG AND AHEAD OF THE FRONT AS IT APPROACHES THE MID STATE,
WITH CLOUD TOPS OVER WESTERN KENTUCKY MUCH COLDER THAN THOSE
OBSERVED OVER MIDDLE TENNESSEE.

BELIEVE SOME SEVERE STORMS ARE INEVITABLE ACROSS MIDDLE TENNESSEE
TODAY, AS THE STORM PREDICTION CENTER HAS PLACED ALL OF THE MID
STATE UNDER A MODERATE RISK OF SEVERE WEATHER. THE PRIMARY THREATS
WILL BE LARGE HAIL AND DAMAGING WIND. BECAUSE THE LOW-LEVEL WIND
PROFILE IS ALMOST UNIFORMLY SOUTHWEST, HELICITY VALUES ARE QUITE
LOW, AND THIS WILL LIKELY INHIBIT SUPERCELL DEVELOPMENT.

MID-LEVEL DYNAMICS ARE QUITE STRONG WITH THIS SYSTEM, WITH STEEP
LAPSE RATES, POSITIVE DIFFERENTIAL VORTICITY BETWEEN 700 AND 500 MB,
AND A PREDICTABLY STRONG OMEGA FIELD. THERE WILL BE SOME DIVERGENCE
IN THE UPPER-LEVEL JET STREAM OVER MIDDLE TENNESSEE, WHICH WILL
CONTRIBUTE TO THE UPWARD VERTICAL MOTION. BUT THE ABSENCE OF A TRUE
40-50 KNOT SOUTHERLY LOW-LEVEL JET -- A PRIME INGREDIENT FOR
SPRINGTIME SEVERE WEATHER -- IS KEEPING A LID ON THE 0-3 KM
HELICITY, AND IS THEREFORE THE KEY FACTOR IN KEEPING THE POTENTIAL
FOR A MAJOR OUTBREAK LOW.

FRONTAL PASSAGE IN MIDDLE TENNESSEE WILL OCCUR DURING THE AFTERNOON
AND EARLY EVENING, WITH SIGNIFICANTLY COOLER AIR AWAITING. TOMORROW
NIGHTS LOW TEMPERATURES WILL APPROACH FREEZING IN SEVERAL
LOCATIONS, AND A FREEZE WARNING MAY HAVE TO BE ISSUED LATER.

THE ONLY OTHER WEATHER SYSTEM IN THE 7-DAY FORECAST WILL SWING
THROUGH THE MID STATE MONDAY NIGHT AND TUESDAY, AND EVEN THEN, THE
SPC HAS NO SEVERE WEATHER MENTIONED BEYOND TODAY.

BNA TB 076/047 053/033 056 08751
    BBEBB 038/065 045/066 046/068 050/070 1-11341111
CKV TB 076/047 053/033 056 08641
    BBEBB 039/064 045/066 046/067 050/071 1-11341111
CSV TE 073/047 052/032 052 08+71
    BBEBB 036/061 041/063 046/067 048/067 1-11341111
&&

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

ROSE

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE NASHVILLE TN
530 AM CDT FRI APR 22 2005

TNZ005>011-022>034-056>066-075-077>080-093>095-231030-
BEDFORD-BENTON-CANNON-CHEATHAM-CLAY-COFFEE-CUMBERLAND-DAVIDSON-
DEKALB-DICKSON-FENTRESS-GILES-GRUNDY-HICKMAN-HOUSTON-HUMPHREYS-
JACKSON-LAWRENCE-LEWIS-MACON-MARSHALL-MAURY-MONTGOMERY-OVERTON-PERRY-
PICKETT-PUTNAM-ROBERTSON-RUTHERFORD-SMITH-STEWART-SUMNER-TROUSDALE-
VAN BUREN-WARREN-WAYNE-WHITE-WILLIAMSON-WILSON-
530 AM CDT FRI APR 22 2005

THIS HAZARDOUS WEATHER OUTLOOK IS FOR MIDDLE TENNESSEE.

.DAY ONE...TODAY AND TONIGHT...
THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS ACROSS MUCH OF
MIDDLE TENNESSEE TODAY THROUGH THIS EVENING. THE AIR MASS WILL REMAIN
UNSTABLE ACROSS MIDDLE TENNESSEE AS A STRONG LOW PRESSURE CENTER
MOVES FROM THE PLAINS THROUGH THE OHIO VALLEY. THE PRIMARY THREAT
IS LARGE HAIL AND DAMAGING WINDS. THE SEVERE WEATHER THREAT WILL
END AFTER A STRONG COLD FRONT MOVES THROUGH THE AREA LATE TODAY
AND THIS EVENING.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY...
MUCH COOLER CONDITIONS ARE EXPECTED FOR SATURDAY AND SUNDAY AS COLD
AIR POURS INTO THE REGION. A CHANCE OF RAIN RETURNS TO THE
FORECAST MONDAY NIGHT AS WINDS WILL TURN BACK TO THE SOUTH AND A
WEAK COOL FRONT MOVES THROUGH THE AREA ON TUESDAY. HIGH PRESSURE
PUSHES BACK IN TO THE AREA ON WEDNESDAY AND THURSDAY. NO HAZARDOUS
WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...
ACTIVATION OF SPOTTERS AND EMERGENCY MANAGERS MAY BE TODAY AND
TONIGHT.

JLM

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NASHVILLE TN
150 AM CDT FRI APR 22 2005

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0120 AM     HAIL             FAIRVIEW                35.98N 87.12W
04/22/2005  0.75 INCH        WILLIAMSON         TN   TRAINED SPOTTER

            REPORT OF 3/4 HAIL IN THE CITY OF FAIRVIEW

&&

JLM

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NASHVILLE TN
705 AM CDT FRI APR 22 2005

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0703 AM     HAIL             OAK HILL                36.08N 86.79W
04/22/2005  0.88 INCH        DAVIDSON           TN   EMERGENCY MNGR

&&

ROSE

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NASHVILLE TN
707 AM CDT FRI APR 22 2005

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0700 AM     HAIL             10 NE CENTERVILLE       35.90N 87.32W
04/22/2005  0.88 INCH        HICKMAN            TN   LAW ENFORCEMENT

            SHERIFFS DEPUTY REPORTED NICKEL SIZE HAIL BEATING DOWN ON
            HIS PATROL CAR.

&&

JLM