Severe Thunderstorm Warning 331, NWS Birmingham, AL

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BIRMINGHAM, AL
300 PM CDT WED JUL 04 2001

OVERALL SYNOPTIC PATTERN WILL AMPLIFY THROUGH THE SHORT TERM PERIOD.
UPPER RIDGE OVER INTER MOUNTAIN WEST BUILDS AND SLIDES EASTWARD AS
EASTERN US TROUGH DIGS AND POSITIONS ITSELF JUST EAST OF THE CWA.
BOTH ETA AND AVN INDICATE SHEAR AXIS ALIGNED NE-SW ACROSS CENTRAL AL
WILL SLIDE SE AS MEAN TROUGH POSITION PUSHES EAST. AS THE TROUGH
MOVES EAST...700 MB AN UP WINDS QUICKLY GAIN A NW TO N COMPONENT
TONIGHT. WATER VAPOR IMAGERY SHOWS MUCH DRIER AIR ALOFT PUSHING
TOWARD THE REGION IN THIS N FLOW. PRECIP WATER VALUES DROP FROM
AROUND 2 IN TO 1-1.5 RANGE. THEREFORE...EXPECT ALITTLE LESS IN THE
WAY OF CONVECTION TOMORROW IN N AL.  SURFACE FRONT PUSHES INTO N AL
LATE THURSDAY AND INTO FRI BUT MOISTURE WILL REMAIN SHALLOW ENOUGH
THAT 20 TO 30 POPS CENTRAL AND SOUTH WILL BE BEST. SHORT RANGE MODELS
KEEP BOUNDARY LAYER MOISTURE AND SURFACE DEW POINTS ABOUT THE SAME...
SO LOW TEMPS MAY ONLY VARY A FEW DEGREES. HIGH TEMPS SHOULD BEGIN
WARMING UP A BIT WITH UPPER RIDGE PUSHING TOWARD THE AREA. GENERALLY
TOOK A MIX OF GUIDANCE NUMBERS.

1ST PERIOD POPS WILL BE SUBJECT TO LATEST OBSERVATIONS AND RADAR
TRENDS..BUT EXPECT A GENERAL DECREASE THROUGH THE EVENING HOURS.
WILL ONCE AGAIN ADD AN EVENING PERIOD TO ZONES.

PRELIM NUMBERS...
HSV BB 069/090 068/093 069 75421--
BHM BB 071/091 069/092 071 75421--
MGM BB 071/0g91 070/094 071 7544211=

.BHM...NONE.

ALZ001>038-040>050-042100-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE BIRMINGHAM AL
100 PM CDT WED JUL 04 2001

HAZARDOUS WEATHER OUTLOOK FOR NORTH AND CENTRAL ALABAMA.

THE AIRMASS OVER THE REGION WILL REMAIN MOIST AND UNSTABLE THROUGH
TONIGHT.  A WEAK UPPER LEVEL TROUGH OF LOW PRESSURE WILL COMBINE
WITH DAYTIME HEATING TO PRODUCE SCATTERED THUNDERSTORMS ACROSS MOST
OF NORTHERN AND CENTRAL ALABAMA THROUGH THE EARLY EVENING HOURS.
THOSE AREAS SOUTH OF A LINE FROM MUSCLE SHOALS TO BIRMINGHAM TO
ROANOKE WILL HAVE THE BEST CHANCE OF EXPERIENCING THUNDERSTORMS
TODAY. MOST OF THE SHOWER AND THUNDERSTORM ACTIVITY SHOULD DIMINISH
BY SUNSET.

WHILE NO ORGANIZED SEVERE WEATHER IS EXPECTED...SOME OF THE STORMS
WILL PRODUCE FREQUENT DANGEROUS CLOUD TO GROUND LIGHTNING AND
TORRENTIAL RAINFALL.  A FEW OF THE STRONGER STORMS MAY ALSO PRODUCE
WIND GUSTS OF UP TO 45 MILES AN HOUR.  BOATERS ON AREA LAKES AND
WATERWAYS NEED TO MINDFUL OF THE THREAT POSED BY LIGHTNING AND
STRONG WIND GUSTS...AND BE PREPARED TO HEAD TO SHORE QUICKLY IF
THUNDERSTORMS APPROACH.

ACTIVATION OF STORM SPOTTERS AND EMERGENCY MANAGEMENT PERSONNEL
SHOULD NOT BE NECESSARY THROUGH TONIGHT.

WET MICROBURST POTENTIAL FACTOR:
HUNTSVILLE IS 1
BIRMINGHAM IS 2
MONTGOMERY IS 3

1 BEING THE LOWEST...AND 5 THE HIGHEST THREAT.

FOR MORE INFORMATION AND A DESCRIPTION OF WHAT A WET MICROBURST IS,
SEE OUR WEBSITE AT WWW.SRH.NOAA.GOV/BMX/HWO.HTML.