Severe Thunderstorm Warning 167, NWS Nashville, TN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NASHVILLE TN
957 PM CDT THU APR 20 2006

.UPDATE...CONVECTION HAS BEEN DEVEOPING RAPIDLY OVER WEST TN AND
WILL BE MOVING INTO THE MID STATE LATE NIGHT. A SVR WATCH IS ON THE
WAY SHORTLY FOR AREAS ALONG AND WEST OF I 65. MAIN THREAT WILL BE
LARGE HAIL. DAMAGING WINDS A POSSIBILITY.

&&

.PREV DISCUSSION... (ISSUED 250 PM CDT THU APR 20 2006)

DISCUSSION...
ATMOSPHERE WILL CONTINUE UNSTABLE THROUGH TONIGHT AND FRIDAY
UNTIL THE SHORTWAVE TROUGH CURRENTLY OVER NEW MEXICO MOVES
NEWD AND TURNS UPPER FLOW TO THE NW BEGINNING FRIDAY EVENING.
GFS SVR INDICES INDICATE THAT INSTABILITY WILL COOL SOMEWHAT
THIS EVENING...WITH THE SOUTHEAST BEING THE MOST UNSTABLE
SECTION. LIFTED INDICES BECOME UNSTABLE AGAIN FRI PM WITH
THE K INDEX AND THE HELICITY RISING ALSO. THUS POPS WILL
REMAIN HIGH THROUGH FRI WITH ZONES MENTION POSSIBLE SEVERE
AGAIN FOR FRI.

ATMOSPHERE REMAINS MOSTLY STABLE THROUGH THE WEEKEND AS A
WEAKLY DEFINED CONVERGENCE ZONE(WARM FRONT?) APPEARS IN THE
FORECAST SUN NGT JUST NORTH OF THE AREA.

THE NEXT LOW PRESSURE CENTER COMES OUT OF THE PLAINS ON MONDAY
DRAGGING THE COLD FRONT TO THE SW BEHIND IT. AS THIS FRONT
APPROACHES...POPS WILL INCREASE IN THE PERIOD MON NGT THROUGH WED.
AFTER THE FRONTAL PASSAGE ON WED AM...A SFC RIDGE MOVES IN OVER THE
AREA WITH NO SGFNT WX EXPECTED FOR WED NGT THROUGH FRI.

MOS TEMPS WERE FAIRLY CLOSE WITH NO BIG DISAGREEMENTS NOTED.
MOS POPS SEEM TO DIVERGE A BIT WITH THE NGM ON THE DRIER SIDE
AND THE GFS AND ETA ON THE WETTER SIDE. FAVORED THE ETA/GFS.

&&

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

13

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE NASHVILLE TN
711 PM CDT THU APR 20 2006

TNZ005>011-022>034-056>066-075-077>080-093>095-211030-
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-
711 PM CDT THU APR 20 2006

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF MIDDLE
TENNESSEE.

.DAY ONE...TONIGHT
A COLD FRONT WILL PUSH INTO THE AREA LATE TONIGHT AND
PRODUCE SCATTERED THUNDERSTORMS.  A FEW MAY BE SEVERE WITH DAMAGING
WINDS AND LARGE HAIL.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY
MORE THUNDERSTORMS ARE LIKELY FRIDAY. THERE IS A CONTINUED THREAT OF
SEVERE WEATHER...AGAIN MAINLY LARGE HAIL AND DAMAGING WINDS. ANOTHER
STRONG FRONT IS DUE AROUND TUESDAY.

.SPOTTER INFORMATION STATEMENT...
EMERGENCY MANAGERS AND SPOTTERS SHOULD KEEP ALERT FOR POSSIBLE
ACTIVATION LATE TONIGHT THROUGH FRIDAY.

19

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE NASHVILLE TN
1223 AM CDT FRI APR 21 2006

TNZ022-024-056>058-093>095-210600-
BENTON-GILES-HICKMAN-HUMPHREYS-LAWRENCE-LEWIS-PERRY-WAYNE-
1223 AM CDT FRI APR 21 2006

...SEVERE THUNDERSTORM WATCH UNTIL 5 AM CDT FOR THE WEST HALF
OF MIDDLE TENNESSEE...

WE ARE MONITORING STORMS CLOSELY MOVING THROUGH NEIGHBORING
COUNTIES JUST WEST OF WAYNE AND PERRY AT THIS TIME.

THUNDERSTORMS HAVE BEEN PRODUCING HAIL TO GOLF BALL SIZE
IN CHESTER COUNTY IN WEST TENNESSEE. THESE STORMS WILL
CONTINUE TO MOVE EAST AND INTO WAYNE AND PERRY COUNTIES
BY 1 AM CDT.

BOYD

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE NASHVILLE TN
228 AM CDT FRI APR 21 2006

TNZ005>007-022>027-056>061-093>095-210800-
BENTON-CHEATHAM-DAVIDSON-DICKSON-GILES-HICKMAN-HOUSTON-HUMPHREYS-
LAWRENCE-LEWIS-MARSHALL-MAURY-MONTGOMERY-PERRY-ROBERTSON-STEWART-
WAYNE-WILLIAMSON-
229 AM CDT FRI APR 21 2006

...SEVERE THUNDERSTORM WATCH UNTIL 5 AM CDT FOR THE WEST HALF
OF MIDDLE TENNESSEE...

STRONG THUNDERSTORMS ARE MOVING THROUGH SOUTHWEST MIDDLE TENNESSEE
AT 230 AM CDT. SEVERE THUNDERSTORM WARNINGS REMAIN IN EFFECT
FOR HICKMAN...LEWIS AND LAWRENCE COUNTIES UNTIL 245 AM CDT.
WE ARE MONITORING THESE STORMS CLOSELY AS THEY MOVE EAST...AND
THEY ARE SHOWING SIGNS OF WEAKENING. THESE STORMS ARE MOVING
INTO AN AREA OF LOW LEVEL WARM ADVECTION AND MOISTURE ADVECTION.
HOWEVER IT IS WELL NORTH OF THE SURFACE BOUNDARY...WHICH IS DOWN
ACROSS ALABAMA. AIR MASS IS EXPECTED TO DESTABILIZE ACROSS
SOUTHERN MIDDLE TENNESSEE DURING THE NEXT FEW HOURS...WHICH
WILL SUPPORT MORE THUNDERSTORM DEVELOPMENT AND OCCASIONAL
LARGE HAIL IN THE STRONGER STORMS. SHEAR PROFILES OFF OKOLONA
PROFILER AND HYTOP ALABAMA RADAR DO NOT SUPPORT ROTATION.

BOYD