Flash Flooding and Damaging Wind in Alabama, June 4, 2010

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BIRMINGHAM AL
1220 PM CDT FRI JUN 4 2010

.UPDATE...AVIATION DISCUSSION.

&&

.DISCUSSION...

THE LATEST SATELLITE IMAGERY DEPICTS A DIFFERENTIAL HEATING AXIS
WEST TO EAST OVER THE FAR SOUTHERN COUNTIES. THIS LOCALIZED
BOUNDARY IS COINCIDENT WITH AN 850MB WIND SHIFT. MIXED LAYER
INSTABILITIES HAVE CAPES 1000-2000 SOUTH WITH NO INHIBITION.
SURFACE BASED LI'S AROUND -5. DOWNDRAFT CAPES ARE IN THE 1000
RANGE IN THE HEATED AREA. IN ADDITION...A MID TO UPPER LEVEL LOW
REMAINS SPINNING NEAR SE TEXAS AND SW LOUISIANA...WITH ADDITIONAL
UPWARD MOTION ROTATING AROUND THE LOW TOWARD SOUTHERN CENTRAL
ALABAMA BY LATE THIS AFTERNOON. THE 12Z SOUNDING HAS PW AROUND 2
INCHES BUT THIS MAY ACTUALLY LOWER SOMEWHAT THIS AFTERNOON TO
AROUND 1.6-1.8 RANGE. THEREFORE...EXPECT CONVECTION TO CONTINUE
DEVELOPING ACROSS THE FAR SOUTHERN ZONES AND MOVING NORTHWARD.
ACTIVITY SHOULD ALSO DEVELOP IN THE DIFFERENTIAL HEATING ZONE WITH
THE AIDE OF THE ENERGY COMING AROUND THE BASE OF THE LOW. DUE TO
THESE IDEAS...HAVE RAISED POPS TO CATEGORICAL AT ALL LOCATIONS.
THE RAIN WILL BE SHOWERY IN NATURE AND HAVE STORM MOTIONS ON THE
ORDER OF 10 TO 15 MPH. WE WILL HAVE TO MONITOR SMALL SCALE
BOUNDARY INTERACTIONS AND STORM CORES FOR THE POTENTIAL OF STRONG
OUTFLOW WINDS. THERE WILL ALSO BE A POTENTIAL OF LOCALIZED HEAVY
RAINFALL WHERE 2 INCHES MAY OCCUR IN A SHORT PERIOD OF
TIME...MAINLY IN BOUNDARY INTERACTION ZONES AND MULTIPLE SHOWERS
OVER THE SAME LOCATIONS. FAIRLY WARM TEMPS ALOFT WILL INHIBIT
LARGE HAIL GROWTH TO ONLY THE STRONGEST ACTIVITY AND IT SHOULD BE
RATHER SMALL...BUT -10 TO -30 CAPE VALUES ARE AROUND 500 SOUTH AT
THIS TIME.

75

&&

.AVIATION...18Z TAF DISCUSSION.

EXPECTING ANOTHER ACTIVE DAY AT NEARLY ALL TAF SITES...AS SHOWERS
AND THUNDERSTORMS ARE EXPECTED TO BE ON THE INCREASE OVER THE NEXT
SEVERAL HOURS.  WILL LIKELY SEE GUSTY WINDS AND PLENTY OF CG
LIGHTNING IN AND AROUND ANY STORMS THAT DEVELOP.  AS WE PROGRESS
THROUGH THE EVENING HOURS...STORMS AND THEIR INTENSITIES WILL
GENERALLY DECREASE...ALTHOUGH ISOLATED TO SCATTERED SHOWERS MAY
STILL DEVELOP ACROSS PORTIONS OF THE AREA. OTHERWISE...JUST SOME MID
LEVEL CLOUDS AND PERHAPS SOME ISOLATED GROUND FOG...ALTHOUGH AM NOT
CONFIDENT ENOUGH TO INCLUDE THE FOG IN THIS ISSUANCE.

NOTICE...KEET TAF WILL HAVE (AMD LTD TO VIS WIND AND WX) AMENDED TO
THE END OF THE FORECAST UNTIL FURTHER NOTICE WHILE CEILOMETER DATA
IS BEING MONITORED FOR ACCURACY.

&&

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

&&

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE BIRMINGHAM AL
636 AM CDT FRI JUN 4 2010

ALZ011>015-017>050-042200-
AUTAUGA-BARBOUR-BIBB-BLOUNT-BULLOCK-CALHOUN-CHAMBERS-CHEROKEE-
CHILTON-CLAY-CLEBURNE-COOSA-DALLAS-ELMORE-ETOWAH-FAYETTE-GREENE-HALE-
JEFFERSON-LAMAR-LEE-LOWNDES-MACON-MARENGO-MARION-MONTGOMERY-PERRY-
PICKENS-PIKE-RANDOLPH-RUSSELL-SHELBY-ST CLAIR-SUMTER-TALLADEGA-
TALLAPOOSA-TUSCALOOSA-WALKER-WINSTON-
636 AM CDT FRI JUN 4 2010

THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE COUNTIES SERVED BY THE
NATIONAL WEATHER SERVICE OFFICE IN BIRMINGHAM.

.DAY ONE...TODAY AND TONIGHT.

A FEW STRONG THUNDERSTORMS ARE POSSIBLE TODAY...FROM NOON UNTIL 8
PM...PRODUCING GUSTY WINDS UP TO 45 MPH. ALTHOUGH THE STORMS WILL
ALSO PRODUCE HEAVY RAINFALL...THEY WILL NOT LIKELY STAY POSITIONED
LONG ENOUGH OVER ONE AREA TO PRODUCE FLASH FLOODING.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY.

AN APPROACHING UPPER LOW WILL PRODUCE SCATTERED TO NUMEROUS
THUNDERSTORMS SATURDAY AND SUNDAY. SOME OF THE STRONGER STORMS
COULD PRODUCE WIND GUSTS UP TO 45 MPH...MAINLY DURING THE AFTERNOON
HOURS.

.SPOTTER INFORMATION STATEMENT...

ACTIVATION OF STORM SPOTTERS AND EMERGENCY MANAGEMENT IS NOT
EXPECTED AT THIS TIME.