Severe Thunderstorm Warning 312, NWS Birmingham, AL

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BIRMINGHAM AL
132 PM CDT SAT JUN 14 2008

.UPDATE...AVIATION AND THIS AFTERNOON DISCUSSION.

&&

.DISCUSSION...THIS AFTERNOON.

WEAK SYNOPTIC BOUNDARY BARELY NOTICEABLE ACROSS CENTRAL
ALABAMA...BUT NUMEROUS MESOSCALE BOUNDARIES EXIST AREAWIDE.
BLOWOFF HIGH CLOUDS FROM WESTERN CONVECTION DISSIPATING ACROSS
CENTRAL ALABAMA WHILE SOME BRIEF SUBSIDENCE NOTED BEHIND THE MVC
NEAR SYLACAUGA. THIS HAS ALLOWED SKIES TO CLEAR AND TEMPS TO
REBOUND INTO THE MID AND UPPER 80S WEST. MAXIMUM INSTABILITY VALUES
EXPECTED UNDER CURRENT LAPS SOUNDING PROFILE INDICATE MODERATE
RISK OF WET MICROBURST. INSTABILITY NUMBERS THEREFORE ARE A BIT
HIGHER THAN I WROTE IN EARLIER DISCUSSIONS...BUT OVERALL OUTCOME
SHOULD BE THE SAME. MAIN THREAT IN STRONGER STORMS WILL BE
LOCALIZED HEAVY RAIN IN A SHORT PERIOD OF TIME...WIND GUSTS 40 TO
50 MPH...DEADLY LIGHTNING...AND POSSIBLY SMALL HAIL. CAN NOT
COMPLETELY RULE OUT A WARNING HERE OR THERE BUT WIDESPREAD SEVERE
STORMS ARE NOT ANTICIPATED. STORMS SHOULD INCREASE IN COVERAGE IN
MOST LOCATIONS THROUGH THE REMAINDER OF THE AFTERNOON. WILL TWEAK
HOURLY GRIDS AGAIN BUT HIGHS LOOK REASONABLE WITH LITTLE
MODIFICATION.

75/LINHARES

&&

.AVIATION...18Z TAF DISCUSSION.

WEAK SYNOPTIC BOUNDARY MOVING SLOWLY ACROSS CENTRAL ALABAMA
THROUGH TONIGHT. ADDITIONALLY...NUMEROUS MESOSCALE BOUNDARIES
EXIST. MOISTURE AND INSTABILITY WILL ALLOW THUNDERSTORMS TO
DEVELOP AREAWIDE. SINCE THE THUNDERSTORMS ARE WIDELY DISTRIBUTED
BUT NUMEROUS...WILL START OFF WITH MENTION OF VCTS FOR MGM/TOI AND
HOLD IT OFF UNTIL 20Z FOR ALL OTHER SITES. WILL KEEP THIS MENTION
THROUGH 02Z AT ALL LOCATIONS BECOMING VCSH THROUGH 05Z. CEILINGS AND
VISIBILITIES WILL GENERALLY BE VFR EXCEPT DIRECTLY UNDER THE
HEAVIER SHOWERS WHERE CEILINGS MAY TEMPORARILY DROP TO MVFR AND
VIS TO IFR. MGM/TOI WILL EXHIBIT LIGHT VARIABLE WINDS WHERE SOME
NORTHERN LIGHT COMPONENT WILL BE NOTICED. SOME FOG DEVELOPMENT
EXPECTED AREAWIDE SOME MENTIONED MVFR VIS 10-13Z.

75

&&

.PREV DISCUSSION... /ISSUED 1039 AM CDT SAT JUN 14 2008/

UPDATE...MESOSCALE DISCUSSION.

DISCUSSION...

CONVECTIVE COMPLEX LAST NIGHT AND EARLY THIS MORNING PRODUCED
RAINFALL OF ONE TO TWO INCHES FROM NEAR HAMILTON TO NEAR ALABASTER.
AFTER ANALYZING THE LATEST SATELLITE IMAGERY...THE OUTFLOW FROM
THIS BATCH OF STORMS WAS LOCATED FROM NEAR LIVINGSTON TO PRATTVILLE
TO LAKE MARTIN. ANOTHER BOUNDARY WAS LOCATED FROM WETUMPKA TO FORT
DEPOSIT. AN MCV APPEARS TO BE LOCATED DIRECTLY OVER THE BIRMINGHAM
METRO AREA. ANOTHER CONVECTIVE COMPLEX WAS ENTERING FAR NORTHWEST
ALABAMA WITH DEVELOPMENT STRETCHING BACK INTO NORTHEAST AND NORTH
CENTRAL MISSISSIPPI. THESE FEATURES WILL SLOWLY MIGRATE EAST AND
SOUTHEAST THROUGH THE AFTERNOON AIDING IN THUNDERSTORM DEVELOPMENT.

THE ATMOSPHERE CAN BE CHARACTERIZED BY HIGH MOISTURE CONTENT WITH
PRECIP WATER VALUES NEAR 2 INCHES...SURFACE DEW POINTS AROUND 70 AND
MEAN RELATIVE HUMIDITY VALUES GENERALLY BETTER THAN 70 PERCENT.
OVERALL...CLOUD COVER WILL LIMIT INSOLATION AND KEEP MDPI AND
WINDEX VALUES IN CHECK...WHICH WILL PROVIDE LOW VALUES FOR WET
MICROBURSTS. BUT THE PRESENCE OF MESOSCALE BOUNDARIES...MID TO
UPPER LEVEL SUPPORT AND GRADUAL COOLING WILL LEAD TO A CHANCE OF
STRONG STORMS WITH LIS EXPECTED -3 TO -5 AND CAPE VALUES UP TO 2500.
THE MAIN THREAT WILL BE LOCALIZED HEAVY RAINFALL UP TO 2 INCHES IN
A SHORT PERIOD OF TIME...GUSTY WINDS UP TO 40 MPH...DEADLY
LIGHTNING...AND POSSIBLY SOME PEA SIZE HAIL.

WILL INCREASE POPS TO AROUND 75 AT MOST LOCATIONS. HIGH TEMPS VERY
TRICKY WITH THE PLACEMENT OF CLOUDS AND PRECIP. IF ANY SUN SHINES
FOR AN HOUR OR TWO...TEMPS WILL CERTAINLY REACH THE MID 80S. WILL
MAKE SOME MINOR ADJUSTMENTS BUT OVERALL HIGHS LOOK REASONABLE.

75/LINHARES

&&

.BMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&

75/90/75

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE BIRMINGHAM AL
227 PM CDT SAT JUN 14 2008

ALZ013-142000-
FAYETTE-
227 PM CDT SAT JUN 14 2008

...SIGNIFICANT WEATHER ALERT FOR FAYETTE COUNTY UNTIL 300 PM CDT...

AT 226 PM CDT...THE NATIONAL WEATHER SERVICE IS TRACKING STRONG
THUNDERSTORMS ALONG A LINE EXTENDING FROM GLEN ALLEN TO 6 MILES
SOUTHEAST OF FAYETTE...OR ALONG A LINE EXTENDING FROM 8 MILES
SOUTHEAST OF WINFIELD TO 6 MILES SOUTHEAST OF FAYETTE...MOVING EAST
AT 11 MPH.

WINDS UP TO 45 MPH AND FREQUENT CLOUD TO GROUND LIGHTNING ARE
EXPECTED WITH THESE STORMS.

STAY TUNED TO NOAA WEATHER RADIO...COMMERCIAL RADIO...OR YOUR LOCAL
TELEVISION STATIONS FOR LATER STATEMENTS AND POSSIBLE WARNINGS
CONCERNING THIS WEATHER SITUATION.

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE BIRMINGHAM AL
256 PM CDT SAT JUN 14 2008

ALZ023-142045-
TUSCALOOSA-
256 PM CDT SAT JUN 14 2008

...SIGNIFICANT WEATHER ALERT FOR TUSCALOOSA COUNTY UNTIL 345 PM
CDT...

AT 249 PM CDT...THE NATIONAL WEATHER SERVICE IS TRACKING STRONG
THUNDERSTORMS ALONG A LINE EXTENDING FROM BOLEY SPRINGS TO 9 MILES
NORTHWEST OF SAMANTHA...OR ALONG A LINE EXTENDING FROM 17 MILES SOUTH
OF CARBON HILL TO 14 MILES NORTHEAST OF GORDO...MOVING SOUTHEAST AT
13 MPH.

WINDS UP TO 50 MPH AND FREQUENT CLOUD TO GROUND LIGHTNING ARE
EXPECTED WITH THESE STORMS.

STAY TUNED TO NOAA WEATHER RADIO...COMMERCIAL RADIO...OR YOUR LOCAL
TELEVISION STATIONS FOR LATER STATEMENTS AND POSSIBLE WARNINGS
CONCERNING THIS WEATHER SITUATION.