Severe Thunderstorm Warning 114, NWS Mobile, AL

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOBILE AL
316 AM CDT TUE APR 22 1997

SFC FNT ACRS CENTRAL SECTIONS OF AL AND MS CONTS TO BE FOCUS FOR SCT
TSTMS. NOT XPTNG FNT TO MOVE ANY MORE SOUTH BUT OUTFLOW BOUNDARIES
WILL DRIFT INTO NRN COUNTIES BY SR. MAIN SFC LOW EXPECTED TO DEVLP
ALNG FNT OVR N MS/N LA THIS AFTERNOON AND MOVE INTO N AL TONIGHT.
MAIN FOCUS OF STG TO SVR ACTIVITY THIS AFTERNOON SHUD BE NORTH OF FA
NEAR SFC LOW BUT COULD SEE SOME TSTMS MOST ANYWHERE IN WRM AIR SOUTH
OF FNT. STMS THAT DEVELOP BFR DARK OVR FA HAVE THE POTENTIAL FOR HAIL
AND STG WNDS AS CAPE VALUES NEAR 2000J/KG FCST IN THE AFTERNOON BUT
BELIEVE BEST CHC FOR SVR FOR MOST OF FA WILL BE AS H5 TROF APPROACHES
FA AFTER SS TUE. LOOKS LIKE A SQUALL LINE TYPE EVENT ENTERING MS FA
AFTER DARK AND EXITING AL/FL FA BEFORE SR WED. BEST SVR THREAT WILL
DEPEND ON TRACK OF SFC LOW BUT SHOULD INCLUDE SVR IN FCST FROM LATE
AFTERNOON THROUGH THE NIGHT. STICK CLOSE TO GUIDANCE BUT RAISE POPS
FOR TONIGHT.

WINDS OVER THE MARINE AREA SHOULD STAY SOUTHWEST AHEAD OF FNT AT 15
TO 20 KTS WITH FNT ENTERING AL WTRS LATE TONIGHT WITH WSHFT TO NW.
SCA LIKELY NEEDED TODAY THRU FCST FOR WINDS AND SEAS.

MOB 81/61/75/51 4+41    PNS 81/63/77/53 3+41
DTS 78/65/77/54 3951    EVR 81/60/70/48 5+41 11

ALZ051>64-MSZ067-075-076-078-079-FLZ001>006-230600-

AREAL THUNDERSTORM OUTLOOK FOR
SOUTHWEST AL...NORTHWEST FL AND SOUTHEAST MS
NATIONAL WEATHER SERVICE MOBILE AL
1105 AM CDT TUE APR 22 1997

THERE IS A MODERATE RISK FOR SEVERE THUNDERSTORMS FOR SOUTHWEST
ALABAMA...NORTHWEST FLORIDA AND SOUTHEAST MISSISSIPPI FROM MID
AFTERNOON THROUGH TONIGHT.

ABUNDANT LOW LEVEL MOISTURE...COOL TEMPERATURES IN THE MID AND UPPER
LEVELS OF THE ATMOSPHERE...AND HEATING OF THE SURFACE BY THE SUN WILL
RESULT IN AN EXTREMELY UNSTABLE ATMOSPHERE ACROSS THE REGION BY
AFTERNOON.  A LOW LEVEL CAP WILL INHIBIT THUNDERSTORM DEVELOP ACROSS
THE AREA THROUGH THE EARLY AFTERNOON HOURS BUT WILL WEAKEN WEST OF
INTERSTATE 65 AS A STRONG UPPER LEVEL DISTUBANCE WITH A SURFACE LOW
PRESSURE SYSTEM ADVANCES INTO EAST CENTRAL MISSISSIPPI BY THE MID
AFTERNOON.  AS THE CAP DISINTEGRATES WEST OF INTERSTATE 65 WITH THE
APPROACH OF THE LOW PRESSURE SYSTEM...A LINE OF STRONG TO SEVERE
THUNDERSTORMS WILL BEGIN TO ENTER SOUTHEAST MISSISSIPI DURING THE MID
AFTERNOON HOURS AND ADVANCE TO A LINE FROM CAMDEN TO GROVE HILL TO
MOBILE DURING THE DINNER HOUR.  AS THE LOW PRESSURE SYSTEM PROGRESSES
FURTHER EAST INTO CENTRAL ALABAMA...THE LINE OF STRONG TO SEVERE
STORMS WILL CONTINUE EAST OF THIS LINE DURING THE EVENING HOURS.

DUE TO THE EXTREMELY UNSTABLE ATMOSPHERE...ISOLATED SEVERE
THUNDERSTORM DEVELOPMENT IN ADVANCE OF THE MAIN LINE OF SEVERE STORMS
CANNOT BE RULED OUT.

THE COMBINATION OF WARM...MOIST AIR AT LOW LEVELS AND COOL...DRY
CONDITIONS ALOFT...AND EXTREMELY UNSTABLE CONDITIONS WILL BE
CONDUCIVE TO THE DEVELOPMENT OF VERY LARGE HAIL AND DAMAGING SURFACE
WINDS WITH THE POSSIBILITY OF ISOLATED TORNADOES.

THE THREAT OF SEVERE STORMS WILL DIMINISH IN THE WAKE OF THE LINE OF
SEVERE STORMS AS TEMPERATURES IN THE LOWER LEVELS WILL HAVE COOLED
DUE TO THE PREVIOUS THUNDERSTORMS RAIN COOLER AIR...THUS HAVING A
STABLIZING EFFECT ON THE ATMOSPHERE.  A COLD FRONT WILL BEGIN TO
ENTER SOUTHEAST MISSISSIPPI BY MIDNIGHT AND PUSH ACROSS SOUTHWEST
ALABAMA AND NORTHWEST FLORIDA THROUGH THE LATE NIGHT HOURS.  DUE TO
THE DECREASED INSTABILITY IN THE WAKE OF THIS AFTERNOONS AND EVENINGS
LINE OF STRONG TO SEVERE STORMS...ONLY SCATTERED SHOWERS AND GENERAL
THUNDERSTORMS ARE EXPECTED WITH THE COLD FRONTAL PASSAGE.

ACTIVATION OF STORM SPOTTERS AND EMERGENCY MANAGEMENT PERSONNEL WILL
LIKELY BE REQUIRED BY MID AFTERNOON THROUGH TONIGHT.