Red Flag Warning 10, NWS Birmingham, AL

AREA FORECAST DISCUSSION...CORRECTED TYPO
NATIONAL WEATHER SERVICE BIRMINGHAM AL
1152 AM CST SUN FEB 21 2010

.UPDATE...FOR MORNING UPDATE, AVIATION, AND FIRE WEATHER.

&&

.DISCUSSION...

UPDATED MAINLY FOR CHANGES IN DEW POINTS IN GRIDS. CLOUDS AND
GREATER MOISTURE HOLDING OFF A LITTLE LONGER. ONLY TWEAKED TEMPS A
TAD HIGHER MAINLY S OF I 85. UPDATED GRIDS/ZONES ALREADY OUT.

08/MNK

&&

.DISCUSSION...
/ISSUED 406 AM CST SUN FEB 21 2010/

SHORT TERM...TODAY THROUGH MONDAY. OVERALL FORECAST STILL ON
TRACK FOR THE FIRST 48 HOURS AS THE NEXT SYSTEM WILL BEGIN TO
APPROACH THE AREA THIS AFTERNOON. ALTHOUGH THERE ARE SOME SUBTLE
DIFFERENCES. THERE DOES NOT APPEAR TO BE AS MUCH PRECIPITATION
ALONG THE WARM FRONT THIS AFTERNOON AS ORIGINALLY BELIEVED...SO
HAVE RE-ORIENTED THE BEGINNING OF THE PRECIPITATION BACK TO THE
WEST...AHEAD OF THE COLD FRONT. CAN NOT RULE OUT ISOLATED SHOWERS
WITH THE WARM FRONT...BUT QUESTIONS LIE WITH JUST HOW FAR NORTH
THE MAIN WARM FRONT WILL LIFT.

AS WE GET INTO THIS EVENING AND INTO THE OVERNIGHT HOURS...WE
WILL SEE THE PRECIPITATION SHIELD SPREAD EAST AND WILL LIKELY
IMPACT MOST OF CENTRAL ALABAMA BY 6 AM MONDAY. SO WENT WITH
CATEGORICAL POPS ALMOST AT ALL LOCATIONS. WE DID KEEP THE HIGHEST
POPS WEST OF THE INTERSTATE 65 CORRIDOR THROUGH MIDNIGHT...AND
THEN MOVED THEM TO EAST OVERNIGHT. THERE IS STILL SOME INSTABILITY
OVER THE AREA OVERNIGHT...SO THERE MAY BE A FEW EMBEDDED
THUNDERSTORMS WITH THE COLD FRONT AS IT MOVES THROUGH OVERNIGHT.
AT THIS TIME NOT EXPECTING ANY BIG IMPACT WITH STORMS... BUT WILL
NEED TO MONITOR. AVERAGE RAINFALL WILL BE HALF TO THREE-QUARTERS
OF AN INCH...SO WE DO NOT ANTICIPATE ANYTHING MORE THAN LOCALIZED
NUISANCE FLOODING IF ANY AT ALL OVERNIGHT.

LOOK FOR THE PRECIPITATION SHIELD TO BE SLOW TO WORK OUT THE
SOUTHEAST ON MONDAY MORNING...SO HAVE GONE WITH LIKELY POPS ACROSS
THE SOUTHEAST THROUGH NOON. SCATTERED SHOWERS AND OR DRIZZLE WILL
STILL BE POSSIBLE THROUGH THE REST OF THE DAY ON MONDAY.

LONG TERM...TUESDAY THROUGH SATURDAY. EYES WILL NOW FOCUS ON A
PACIFIC SYSTEM THAT WILL SLIDE OUT THE PLAINS. THIS SYSTEM IS
PROGGED TO IMPACT THE AREA ON TUESDAY NIGHT INTO WEDNESDAY
MORNING. PRIOR TO TONIGHT...CONFIDENCE HAD BEEN LOW WITH THIS
SYSTEM. NOW WITH THE CURRENT MODEL RUNS... CONFIDENCE IS EVEN
LOWER...IF THAT COULD ACTUALLY HAPPEN. MODELS ARE HAVING A VERY
HARD TIME CAPTURING WHAT WILL OCCUR AS FAR AS PRECIPITATION AND
PLACEMENT OF THIS SHORTWAVE WITHIN THIS LONGWAVE PATTERN AND THE
SHIFT THAT WILL TAKE PLACE OVER THE CONUS. THE ONE THING THAT THE
MODELS ARE SOMEWHAT CONSISTENT ON IS THAT THERE WILL BE SOME
PRECIPITATION WITH THE SHORTWAVE. THE PROBLEM OCCURS WITH THE
PLACEMENT OF THIS SHORTWAVE. THE 00Z/06Z GFS AND 00Z GEM KEEP THE
PRECIPITATION ACROSS THE SOUTH WITH COLDER TEMPERATURES ACROSS THE
NORTH. THE 00Z NAM CAME IN WITH PRECIPITATION ALONG THE INTERSTATE
59 CORRIDOR AND SLIGHTLY WARMER TEMPERATURES. AND THE 00Z EURO
CAME IN WITH PRECIPITATION ACROSS ALL OF CENTRAL ALABAMA AND EVEN
WARMER TEMPERATURES. WITH THE 6Z MODELS COMING IN...THE NAM IS
FURTHER SOUTH AND MORE IN LINE WITH THE 00Z/06Z GFS AND GEM. TO
THROW EVEN MORE CONFUSION IN...THE 12Z EURO FROM SATURDAY DID NOT
HAVE ANY PRECIPITATION IN AT ALL.

TO TAKE INTO ACCOUNT FOR THIS UNCERTAINTY WILL GO WITH A BLEND OF
THE MODELS AND KEEP A SLIGHT CHANCE OF RAIN ACROSS MUCH OF THE AREA
WITH ABOVE FREEZING TEMPERATURES WEDNESDAY MORNING. SO WITH ALL
THESE FACTORS HAVE ELECTED TO REMOVE THE MENTION OF SNOW FROM THE
FORECAST. HOWEVER...MODELS ARE SHOWING THE CRITICAL THICKNESSES ARE
GOOD FOR A SWITCHOVER FROM RAIN TO SNOW...BUT WE HAVE NOT SHARED TO
WELL WITH POST-FRONTAL SNOWS SO FAR THIS YEAR. WE MAY HAVE TO ADD
SNOW BACK IN AS THE SYSTEM GETS CLOSER...BUT CONFIDENCE IS JUST
TOO LOW TO CONTINUE TO MENTION FOR NOW.

WHAT WE ARE FAIRLY CONFIDENT IN IS THE FACT THAT THE COLD
TEMPERATURES WILL MOVE BACK INTO THE AREA FOR THE END OF THE WEEK.
MODELS ARE TOO WARM FOR THURSDAY AND FRIDAY...SO WILL UNDERCUT BY A
FEW DEGREES EACH DAY. SOMEWHAT OF A WARM UP BY NEXT WEEKEND...BUT
MORE ON THAT IN THE UPCOMING DAYS.

16

&&

.AVIATION...18Z TAF DISCUSSION.

A STORM SYSTEM WILL BEGIN AFFECTING CENTRAL ALABAMA LATE THIS
AFTERNOON INTO THE EVENING AS A WARM FRONT LIFTS NORTHWARD. NOT
TOO MUCH CHANGE IN THE TAFS. PUSHED BACK INITIAL CLOUDS COMING IN
A FEW HRS. RAIN STILL EXPECTED FOR MAINLY OVERNIGHT HRS. LEFT OUT
THUNDERSTORM MENTION AS ALTHOUGH IT IS A POSSIBILITY CONFIDENCE IS
LOW AT ANY ONE POINT...WHEREAS CONFIDENCE IS MUCH HIGHER THAT RAIN
WILL OCCUR BEGINNING THIS EVENING...ALONG WITH LOW CIGS LATE.
POSSIBLY AN ISOLATED GUST OR SO WITH ANY STRONGER ACTIVITY IS NOT
OUT OF THE QUESTION...BUT OVERALL WINDS SHOULD REMAIN LIGHT.

REMINDER NOTE: WILL CONTINUE TO INCLUDE THE LINE (AMD LTD TO VIS
WIND AND WX) FOR KEET DUE TO CONTINUED CONCERN OVER THE
CEILOMETER. THE CEILOMETER WILL BE IN TESTING PHASE THROUGH
FEBRUARY.

08

&&

.FIRE WEATHER...

DRIER DEW POINTS THAN PREVIOUSLY ANTICIPATED ARE OCCURRING.
MOISTURE...CLOUD COVER AND RAIN ARE TAKING LONGER TO MOVE IN FROM
THE SOUTHWEST. HAVE DECIDED TO ISSUE A RED FLAG WARNING FOR
NORTHERN PORTIONS OF CENTRAL ALABAMA...GENERALLY ALONG AND NORTH
OF A WINFIELD TO HOOVER TO RANBURNE LINE THROUGH 6 PM.

08/MNK

&&

.PRELIMINARY POINT TEMPS/POPS...
GADSDEN     66  44  62  38  50 /  10 100  30  10  10
ANNISTON    68  47  63  38  53 /  10 100  30  10  10
BIRMINGHAM  68  49  62  36  53 /  10 100  20  10  10
TUSCALOOSA  68  50  63  37  56 /  20 100  10  10  10
CALERA      67  50  63  38  53 /  10 100  20  10  10
AUBURN      69  49  67  40  55 /  10  80  50  10  10
MONTGOMERY  69  50  66  41  58 /  10  90  40  10  10
TROY        70  51  68  42  58 /  10  80  50  10  10

&&

.BMX WATCHES/WARNINGS/ADVISORIES...

RED FLAG WARNING UNTIL 6 PM SUNDAY FOR ALZ011-ALZ014-ALZ015-
ALZ017-ALZ018-ALZ019-ALZ020-ALZ021-ALZ024-ALZ026...FOR THE
NORTHERN SECTIONS OF CENTRAL ALABAMA...ALONG AND NORTH OF A
WINFIELD TO HOOVER TO RANBURNE LINE.

&&

08/16/08/08

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE BIRMINGHAM AL
634 AM CST SUN FEB 21 2010

ALZ011>015-017>050-221230-
MARION-LAMAR-FAYETTE-WINSTON-WALKER-BLOUNT-ETOWAH-CALHOUN-
CHEROKEE-CLEBURNE-PICKENS-TUSCALOOSA-JEFFERSON-SHELBY-ST. CLAIR-
TALLADEGA-CLAY-RANDOLPH-SUMTER-GREENE-HALE-PERRY-BIBB-CHILTON-
COOSA-TALLAPOOSA-CHAMBERS-MARENGO-DALLAS-AUTAUGA-LOWNDES-ELMORE-
MONTGOMERY-MACON-BULLOCK-LEE-RUSSELL-PIKE-BARBOUR-
634 AM CST SUN FEB 21 2010

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

.DAY ONE...TODAY AND TONIGHT.

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY.

GUSTY WINDS ARE POSSIBLE WEDNESDAY ACROSS CENTRAL ALABAMA. AS A
STORM SYSTEM EXITS TO THE EAST AND HIGH PRESSURE BUILDS INTO THE
AREA...A TIGHTENED PRESSURE GRADIENT WILL LEAD TO INCREASED
NORTHWESTERLY WINDS.

.SPOTTER INFORMATION STATEMENT...

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