Red Flag Warning 12, NWS Birmingham, AL

Autauga County, AL, Barbour County, AL, Bibb County, AL, Blount County, AL, Bullock County, AL, Calhoun County, AL, Chambers County, AL, Cherokee County, AL, Chilton County, AL, Clay County, AL, Cleburne County, AL, Coosa County, AL, Dallas County, AL, Elmore County, AL, Etowah County, AL, Fayette County, AL, Greene County, AL, Hale County, AL, Jefferson County, AL, Lamar County, AL, Lee County, AL, Lowndes County, AL, Macon County, AL, Marengo County, AL, Marion County, AL, Montgomery County, AL, Perry County, AL, Pickens County, AL, Pike County, AL, Randolph County, AL, Russell County, AL, Shelby County, AL, St. Clair County, AL, Sumter County, AL, Talladega County, AL, Tallapoosa County, AL, Tuscaloosa County, AL, Walker County, AL, Winston County, AL

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BIRMINGHAM AL
605 AM CDT FRI MAR 21 2008

.UPDATE...AVIATION DISCUSSION.

.SHORT TERM...TODAY AND TONIGHT.

FEEL PRETTY CONFIDENT THAT AT LEAST SOME OF THE NORMALLY COLDER
VALLEY AREAS ETC. WILL DROP INTO THE MID 30S BY DAYBREAK SO WILL
LET CURRENT FROST ADVISORY RUN ITS COURSE.  OTHERWISE...HIGH
PRESSURE WILL REMAIN IN CONTROL ACROSS CENTRAL ALABAMA DURING THE
PERIOD...WHILE SLIDING GRADUALLY EASTWARD.  THIS WILL ALLOW A
LIGHT SOUTHEASTERLY FLOW TO DEVELOP ACROSS THE AREA TODAY...ALLOWING
TEMPERATURES TO WARM ABOVE YESTERDAYS VALUES.  850 MB TEMPS AND
THICKNESSES ALSO SUPPORT THIS.  MOISTURE WILL REMAIN LIMITED TODAY
WITH ONLY SOME THIN CIRRUS EXPECTED ACROSS THE AREA.  AS THE HIGH
SLIDES FURTHER EAST TONIGHT THE FLOW SHOULD BECOME MORE SOUTHERLY
AND MODELS SUGGEST SOME LOW LEVEL MOISTURE COULD BEGIN TO RETURN TO
THE AREA TOWARD DAYBREAK SATURDAY...BUT DO NOT EXPECT MORE THAN
SCATTERED CLOUDS AT THIS TIME...MAINLY IN THE NORTHWEST SECTIONS OF
THE AREA.  LOW TEMPS WILL HOLD PRIMARILY IN THE 40S WITH THE LIGHT
SOUTHERLY FLOW.

41

.LONG TERM...SATURDAY THROUGH THURSDAY.

OVERALL A DRY FORECAST WILL CONTINUE THROUGH WEDNESDAY. WE WILL
SEE TWO WEAK COLD FRONTS SLIDE THROUGH THE AREA. THE FIRST WILL
BE ON SATURDAY AND THE SECOND ON SUNDAY NIGHT/MONDAY MORNING. LATEST
MODELS INDICATE THAT BOTH SYSTEMS WILL MOVE THROUGH DRY...SO HAVE
REMOVED ALL PRECIPITATION FROM THE FORECAST. THE NEXT CHANCE OF RAIN
WILL BE AT THE END OF THE PERIOD...MAINLY THURSDAY AND NEXT FRIDAY.
RIGHT NOW THE GFS AND ECMWF ARE ABOUT 24 HOURS APART ON THIS...BUT
BOTH DO AGREE THAT A SYSTEM WILL MOVE THROUGH. MORE ON THIS SYSTEM
AS IT APPROACHES THE AREA.

THE MAIN CONCERN WITH THIS FORECAST WILL BE THE DAILY BATTLES WITH
POSSIBLE FROST AND FREEZING TEMPERATURES...NOW THAT GROWING SEASON
IS IN MOTION. A COLDER...CONTINENTAL HIGH PRESSURE SYSTEM WILL
MOVE INTO CENTRAL ALABAMA MONDAY AND WILL REMAIN THROUGH
WEDNESDAY. AT THIS TIME...LOOKS LIKE THE BEST SHOT AT FREEZING
TEMPERATURES WILL BE TUESDAY MORNING. OTHER DAYS THAT WILL NEED TO
BE MONITORED WILL BE SUNDAY AND MONDAY MORNINGS. ON SUNDAY MORNING
TEMPERATURES WILL BE CHILLY...BUT WINDS SHOULD REMAIN UP DURING
THE NIGHT...LIMITING THE THREAT OF FROST. MEANWHILE...MONDAY
MORNING...MAY BE TOO DRY FOR FROST AS DEWPOINT DEPRESSIONS WILL BE
4 TO 6 DEGREES. WILL NEED TO KEEP A CLOSE EYE ON TEMPERATURES
THROUGH MIDWEEK.

16

&&

.AVIATION...12Z TAF DISCUSSION.

VFR CONDITIONS THROUGH THE PERIOD. LIGHT SOUTHEAST WINDS WILL
GRADUALLY BECOME MORE SOUTHERLY AFTER 18Z AS THE SURFACE RIDGE
OVER THE AREA MOVES OFF TO THE EASTS.  COULD SEE SOME SCT CLOUDS
NEAR 2 THSD FT IN THE AREA AFTER 08Z AS LOW LEVEL MOISTURE BEGINS
TO INCREASE BUT DO NOT EXPECT CEILINGS TO DEVELOP AT THIS TIME.

41

&&

.FIRE WEATHER...

WITH TEMPERATURES FORECAST TO BE IN THE UPPER 60S TO LOW
70S...AND DEWPOINTS IN THE LOW 30S...RH VALUES ARE FORECAST TO
FALL BELOW 25 PERCENT FOR 1 TO 2 HOURS THIS AFTERNOON. THIS WILL
RESULT IN MARGINAL RED FLAG CONDITIONS THIS AFTERNOON...HOWEVER
DURATION AND WINDS WILL REMAIN BELOW LOCAL CRITERIA FOR ANY
WARNINGS. ANOTHER FACTOR INTO THIS...WILL BE THE RECENT RAINS
MOST OF THE AREA HAS RECEIVED. MOST OF THE FUELS ARE STILL WET
ACROSS MOST OF CENTRAL ALABAMA.

HOWEVER...ONE THING TO KEEP IN MIND IS THAT IF DEWPOINTS DROP
LOWER THAN THE FORECAST THIS AFTERNOON...WHEN MAXIMUM MIXING IS
REALIZED...THE RH VALUES MAY FALL LOWER...ALTHOUGH TEMPORARILY. AT
THIS TIME NOT ENOUGH CONFIDENCE OF THIS HAPPENING...BUT WANTED TO
MENTION THE POSSIBILITY...ESPECIALLY ACROSS SOUTHERN PORTIONS OF
CENTRAL ALABAMA...WHERE THE RAIN WAS NOT AS WIDESPREAD. THANKS FOR
THE COLLABORATION THIS MORNING...SPC...HUN...FFC.

16

&&

.BMX WATCHES/WARNINGS/ADVISORIES...
AL...FROST ADVISORY ALL ZONES VALID UNTIL 8 AM CDT FRIDAY.

&&

41/16

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE BIRMINGHAM AL
545 AM CDT FRI MAR 21 2008

ALZ011>015-017>050-221100-
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-
545 AM CDT FRI MAR 21 2008

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

.DAY ONE...TODAY AND TONIGHT.

A FROST ADVISORY HAS BEEN ISSUED UNTIL 8 AM FOR ALL OF CENTRAL
ALABAMA.  SCATTERED FROST WILL OCCUR EARLY TODAY..ESPECIALLY IN
NORMALLY COLDER VALLEYS AND LOW LYING RURAL AREAS. THE FROST COULD
BE DAMAGING TO TENDER PLANTS NOW THAT WE ARE IN THE EARLY STAGES OF
THE GROWING SEASON.

OTHERWISE NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

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

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

ACTIVATION OF STORM SPOTTERS AND EMERGENCY MANAGEMENT WILL NOT BE
NECESSARY.