Frost Advisory 1, NWS Birmingham, AL

838 
WWUS74 KBMX 250212
NPWBMX

URGENT - WEATHER MESSAGE
NATIONAL WEATHER SERVICE BIRMINGHAM AL
912 PM CDT THU MAR 24 2011

...PATCHY FROST POSSIBLE TONIGHT...

.COLD HIGH PRESSURE WILL BUILD INTO CENTRAL ALABAMA TONIGHT.
LIGHT WINDS AND CLEAR SKIES WILL ALLOW TEMPERATURES TO FALL TO
NEAR FREEZING ACROSS NORTH CENTRAL ALABAMA...ALLOWING PATCHY
FROST TO DEVELOP ON VEGETATION AND GROUND SURFACES.

ALZ036>038-251400-
/O.EXA.KBMX.FR.Y.0001.110325T0600Z-110325T1400Z/
COOSA-TALLAPOOSA-CHAMBERS-
INCLUDING THE CITIES OF...ROCKFORD...ALEXANDER CITY...DADEVILLE...
VALLEY...LANETT...LAFAYETTE
912 PM CDT THU MAR 24 2011

...FROST ADVISORY IN EFFECT FROM 1 AM TO 9 AM CDT FRIDAY...

THE NATIONAL WEATHER SERVICE IN BIRMINGHAM HAS ISSUED A FROST
ADVISORY...WHICH IS IN EFFECT FROM 1 AM TO 9 AM CDT FRIDAY. 

THE COMBINATION OF TEMPERATURES IN THE LOW TO MID 30S...LIGHT
WINDS AND CLEAR SKIES WILL ALLOW PATCHY FROST TO DEVELOP
OVERNIGHT. DUE TO THE RECENT WARM WEATHER...SOME VEGETATION HAS
ALREADY BUDDED OR BLOOMED. PERSONS WITH AGRICULTURAL INTEREST
SHOULD TAKE PREVENTATIVE MEASURES TO ENSURE THAT TENDER
VEGETATION IS PROTECTED.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FROST ADVISORY MEANS THAT FROST IS POSSIBLE. SENSITIVE OUTDOOR
PLANTS MAY BE KILLED IF LEFT UNCOVERED.

&&

$$

ALZ011>015-017>021-024>029-251400-
/O.CON.KBMX.FR.Y.0001.110325T0600Z-110325T1400Z/
MARION-LAMAR-FAYETTE-WINSTON-WALKER-BLOUNT-ETOWAH-CALHOUN-
CHEROKEE-CLEBURNE-JEFFERSON-SHELBY-ST. CLAIR-TALLADEGA-CLAY-
RANDOLPH-
INCLUDING THE CITIES OF...HAMILTON...SULLIGENT...VERNON...
FAYETTE...DOUBLE SPRINGS...JASPER...ONEONTA...GADSDEN...
ANNISTON...CENTRE...HEFLIN...BIRMINGHAM...HOOVER...COLUMBIANA...
PELHAM...ALABASTER...PELL CITY...MOODY...TALLADEGA...SYLACAUGA...
ASHLAND...ROANOKE
912 PM CDT THU MAR 24 2011

...FROST ADVISORY REMAINS IN EFFECT FROM 1 AM TO 9 AM CDT
FRIDAY...

A FROST ADVISORY REMAINS IN EFFECT FROM 1 AM TO 9 AM CDT FRIDAY. 

THE COMBINATION OF TEMPERATURES IN THE LOW TO MID 30S...LIGHT
WINDS AND CLEAR SKIES WILL ALLOW PATCHY FROST TO DEVELOP
OVERNIGHT. DUE TO THE RECENT WARM WEATHER...SOME VEGETATION HAS
ALREADY BUDDED OR BLOOMED. PERSONS WITH AGRICULTURAL INTEREST
SHOULD TAKE PREVENTATIVE MEASURES TO ENSURE THAT TENDER
VEGETATION IS PROTECTED.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FROST ADVISORY MEANS THAT FROST IS POSSIBLE. SENSITIVE OUTDOOR
PLANTS MAY BE KILLED IF LEFT UNCOVERED.

&&

$$

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BIRMINGHAM AL
1220 PM CDT THU MAR 24 2011

.UPDATE...18Z AVIATION.

&&

.DISCUSSION...

BREEZY NW WINDS WILL PERSIST THRU THE AFTN WITH SUSTAINED WINDS OF
GENERALLY 10-12 KTS AND GUSTS UP TO 20 KTS. A CU FIELD HAS
DEVELOPED ACROSS THE FAR NERN PORTIONS OF THE CWA THIS MRNG.
EXPECT THESE CLOUDS TO SLOWLY DISSIPATE BY THIS EVNG. AFTN HIGHS
SHOULD TOP OUT IN THE LOW 60S NORTH TO LOW 70S SOUTH. ONLY
ADJUSTMENTS NEEDED TO THE FORECAST WERE FOR HOURLY TEMPS AND DEW
POINTS. HIGH PRESSURE WILL BUILD IN TONIGHT...WITH LOW TEMPS
FALLING INTO THE LOW TO MID 30S ACROSS THE NORTH. SINCE WE HAVE
NOW ENTERED THE GROWING SEASON WILL HAVE TO WATCH CLOSELY FOR A
POSSIBLE FROST ADVISORY TONIGHT.

19

&&

.AVIATION...
18Z TAF DISCUSSION.

BREEZY NW WINDS WILL CONTINUE THRU THE AFTN THANKS TO A SOMEWHAT
TIGHTER PRESSURE GRADIENT IN PLACE ACROSS MUCH OF THE REGION.
SUSTAINED WINDS OF 10-12 KTS WITH GUSTS UP TO 20 KTS CAN BE
EXPECTED. WINDS WILL DECREASE AND SHIFT TO THE N THIS EVNG AS SFC
HIGH PRESSURE BUILDS INTO THE AREA. THE RIDGE THE WILL SLOWLY PUSH
EWD ON FRI ALLOWING WINDS TO SHIFT AROUND TO THE W BY MID MRNG.

NOTICE...KEET TAF WILL HAVE (AMD LTD TO VIS WIND AND WX) AMENDED TO
THE END OF THE FORECAST UNTIL FURTHER NOTICE. THE CEILOMETER DATA
WILL BE GOING THROUGH NUMEROUS TESTS AND MONITORED FOR ACCURACY.

19

&&

.PREV DISCUSSION... /ISSUED 622 AM CDT THU MAR 24 2011/

SHORT TERM...TODAY THROUGH FRIDAY NIGHT.

THE COLD FRONT HAS PUSHED THROUGH MOST OF THE AREA THIS MORNING.
COOLER TEMPERATURES ARE EXPECTED THROUGH FRIDAY WITH A LIGHT FROST
POSSIBLE FRIDAY MORNING ACROSS THE NORTH. CLOUDS ROLL IN FRIDAY
NIGHT WITH A CHANCE OF SHOWERS ACROSS THE NORTHERN HALF OF THE
AREA AFTER MIDNIGHT.

LONG TERM...SATURDAY THROUGH WEDNESDAY.

AN UNSETTLED PATTERN FOR THE WEEKEND AND REALLY MUCH OF EARLY NEXT
WEEK. SEVERAL ROUNDS OF SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE
AS SURFACE LOW PRESSURE SHIFTS THROUGH THE STATE ALONG OR NEAR A
STALLED FRONTAL BOUNDARY. UPPER LEVEL PATTERN CONSISTS OF ZONAL
FLOW WITH EMBEDDED SHORTWAVE ENERGY WHICH SHOULD WORK FAVORABLY
WITH GOOD SURFACE BASED INSTABILITY THROUGHOUT THE DAY SATURDAY.
THERE REMAINS SOME THREAT OF SEVERE WEATHER OVER THE WEEKEND
ALTHOUGH DETAILS REMAIN BURIED IN THE MESOSCALE. STILL LIKE THE
IDEA OF A MORE MCS DRIVEN EVENT ALTHOUGH FORECAST SOUNDINGS ARE
ALSO SUPPORTIVE OF SUPERCELLS. EVERYONE STANDS TO SEE A CHANCE OF
SOME RAINFALL OVER THE WEEKEND HOWEVER THE BETTER CHANCES WILL BE
NEAR THE BOUNDARY ACROSS THE NORTHERN HALF OF THE STATE.

MUCH UNCERTAINTY WITH WHAT HAPPENS MONDAY THROUGH WEDNESDAY AS THE
ONCE DYNAMIC LOOKING SYSTEM ORIGINALLY FORECAST TO ARRIVE
MONDAY/MONDAY NIGHT HAS NOW FLATTENED OUT AND SPED UP. THE 00Z
MODELS ARE GENERALLY FORECASTING A CLEARING COLD FRONT TO PUSH
THROUGH ON MONDAY MORNING WITH HIGH PRESSURE BRIEFLY BUILDING IN
FOR MONDAY NIGHT AND TUESDAY. ANOTHER STORM SYSTEM BY THE END OF
THE FORECAST PERIOD BUT ALL OF THIS IS COMPLETELY DIFFERENT FROM
YESTERDAY. WILL KEEP POPS IN THE HIGH CHANCE RANGE FOR MONDAY AND
THEN TAPER DOWN TO SLIGHT CHANCE AFTER THAT.

88

&&

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

&&

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE BIRMINGHAM AL
101 PM CDT THU MAR 24 2011

ALZ011>015-017>050-251801-
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-
101 PM CDT THU MAR 24 2011

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

.DAY ONE...THIS AFTERNOON AND TONIGHT.

COLD TEMPERATURES ARE EXPECTED TONIGHT AS HIGH PRESSURE BRIEFLY
BUILDS INTO THE AREA. OVERNIGHT LOWS WILL DROP INTO THE LOW TO MID
30S ACROSS THE NORTHERN HALF OF THE AREA...WITH PATCHY FROST
POSSIBLE GENERALLY ALONG AND NORTH OF A LINE FROM VERNON...TO
SYLACAUGA...TO ROANOKE. SOME LOCALLY COOLER SITES MAY REACH THE
FREEZING MARK BRIEFLY AS WELL.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY.

THERE IS A CHANCE OF SEVERE THUNDERSTORMS...INCLUDING THE THREAT
OF DAMAGING WINDS AND LARGE HAIL...ACROSS PORTIONS OF CENTRAL
ALABAMA DURING THE SATURDAY THROUGH MONDAY TIME FRAME. THE SEVERE
WEATHER THREAT WILL NOT BE CONTINUOUS DURING THIS TIME...BUT MAY COME
IN SEVERAL WAVES.

THE MOST LIKELY TIME FOR THE FIRST WAVE OF STORMS IS SATURDAY
AFTERNOON AND SATURDAY NIGHT.  CONFIDENCE IN THE SEVERE THREAT FOR
SATURDAY IS INCREASING...BUT THE TORNADO THREAT IS DECREASING.
THEREFORE THE MAIN THREATS WILL BE DAMAGING WINDS AND LARGE HAIL. A
FEW STRONG TO SEVERE THUNDERSTORMS MAY CONTINUE OR REDEVELOP ON
SUNDAY...MAINLY ACROSS THE SOUTH...AS A COLD FRONT PUSHES THROUGH THE
AREA. ANOTHER ROUND OF SEVERE WEATHER COULD BE POSSIBLE AGAIN ON
MONDAY ACROSS THE SOUTH IF THE FRONT STALLS OVER THE AREA.

BECAUSE THE COMPUTER MODELS ARE STILL HAVING A HARD TIME DEALING
WITH THE SPECIFICS...MOST NOTABLY THE LOCATION AND MOVEMENT OF
THE COLD FRONT...FORECAST CONFIDENCE REMAINS LOW FOR LATE SUNDAY INTO
MONDAY AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

ACTIVATION OF STORM SPOTTERS AND EMERGENCY MANAGEMENT MAY BE
NECESSARY OVER THE WEEKEND.