Frost Advisory 5, NWS Birmingham, AL

173 
WWUS74 KBMX 132048
NPWBMX

URGENT - WEATHER MESSAGE
NATIONAL WEATHER SERVICE BIRMINGHAM AL
248 PM CST FRI NOV 13 2015

...FREEZE AND FROST POSSIBLE ACROSS NORTH CENTRAL ALABAMA
TONIGHT...

.AS TEMPERATURES FALL INTO THE 32 TO 36 DEGREE RANGE TONIGHT...
AREAS OF FROST ARE POSSIBLE ACROSS NORTH CENTRAL ALABAMA. IN FAR
NORTH CENTRAL ALABAMA...WITH TEMPERATURES NEAR 32 DEGREES...A
FREEZE IS POSSIBLE...ESPECIALLY AT SHELTERED LOCATIONS.
TEMPERATURES WILL WARM QUICKLY SATURDAY MORNING AS THE SUN RISES.

ALZ011-014-017-018-020-141300-
/O.CON.KBMX.FZ.W.0003.151114T0600Z-151114T1300Z/
MARION-WINSTON-BLOUNT-ETOWAH-CHEROKEE-
INCLUDING THE CITIES OF...HAMILTON...DOUBLE SPRINGS...ONEONTA...
GADSDEN...CENTRE
248 PM CST FRI NOV 13 2015

...FREEZE WARNING REMAINS IN EFFECT FROM MIDNIGHT TONIGHT TO 7 AM
CST SATURDAY...

* TEMPERATURES...32 DEGREES FOR SEVERAL HOURS BEFORE SUNRISE.

* IMPACTS...FREEZING TEMPERATURES WILL DAMAGE OR DESTROY 
  SENSITIVE VEGETATION. TAKE PRECAUTIONS TONIGHT TO PROTECT 
  OUTDOOR PLANTS. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FREEZE WARNING MEANS SUB-FREEZING TEMPERATURES ARE IMMINENT OR
HIGHLY LIKELY. THESE CONDITIONS WILL KILL CROPS AND OTHER
SENSITIVE VEGETATION.

&&

$$

ALZ012-013-015-019-021>029-141300-
/O.CON.KBMX.FR.Y.0005.151114T0600Z-151114T1300Z/
LAMAR-FAYETTE-WALKER-CALHOUN-CLEBURNE-PICKENS-TUSCALOOSA-
JEFFERSON-SHELBY-ST. CLAIR-TALLADEGA-CLAY-RANDOLPH-
INCLUDING THE CITIES OF...SULLIGENT...VERNON...FAYETTE...JASPER...
ANNISTON...HEFLIN...CARROLLTON...TUSCALOOSA...BIRMINGHAM...
HOOVER...COLUMBIANA...PELHAM...ALABASTER...PELL CITY...MOODY...
TALLADEGA...SYLACAUGA...ASHLAND...ROANOKE
248 PM CST FRI NOV 13 2015

...FROST ADVISORY REMAINS IN EFFECT FROM MIDNIGHT TONIGHT TO 7 AM
CST SATURDAY...

* TEMPERATURES...34 TO 38 DEGREES BETWEEN MIDNIGHT AND SUNRISE.

* IMPACTS...FROST COULD DAMAGE SENSITIVE VEGETATION. TAKE 
  PRECAUTIONS TONIGHT TO PROTECT OUTDOOR PLANTS. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

$$

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BIRMINGHAM AL
331 AM CST FRI NOV 13 2015

.DISCUSSION...

TODAY AND TONIGHT...

HIGH PRESSURE SPREADS INTO THE SOUTHEASTERN CONUS TODAY...KEEPING
CONDITIONS DRY AND SKIES MOSTLY CLEAR. DEWPOINTS WILL FALL INTO THE
MID 20S TO LOWER 30S TODAY AS HIGHS WARM INTO THE 60S. TONIGHT...
THE CENTER OF THE SURFACE HIGH REMAINS JUST TO OUR NORTH WITH NORTH
CENTRAL ALABAMA ON THE SOUTHERN EDGE OF THE BEST RADIATIONAL COOLING
SETUP. COLD ADVECTION WILL CONTINUE WITH 850MB REMAINING AROUND 20-
25KTS...BUT WINDS SHOULD DECOUPLE AT THE SURFACE. TEMPERATURES WILL
FALL INTO THE LOW TO MID 30S FOR MUCH OF THE AREA.

THERE IS A GOOD CHANCE LOCATIONS IN THE NORTHERN TIER OF COUNTIES
WILL COOL TO OR JUST BELOW 32 DEGREES...ESPECIALLY SHELTERED
LOCATIONS. WILL ISSUE A FREEZE WARNING FOR THOSE COUNTIES. FURTHER
SOUTH...AREAS OF FROST ARE POSSIBLE AS TEMPERATURES COOL TO NEAR OR
BELOW 34 DEGREES AND WILL ISSUE A FROST ADVISORY FOR THE NORTHERN
HALF OF THE AREA. FURTHER SOUTH...SHELTERED LOCATIONS COULD DROP
BELOW 36 DEGREES FOR A COUPLE HOURS RESULTING IN LIGHT PATCHY
FROST...AND A MENTION IN THE GRIDS IS SUFFICIENT TO COVER THAT
POSSIBILITY.

14

SATURDAY THROUGH THURSDAY...

SURFACE HIGH PRESSURE WILL BE IN PLACE ACROSS THE REGION ON
SATURDAY  WITH SUNNY SKIES AND A MILD AFTERNOON. TEMPERATURES
WILL FALL QUICKLY DURING THE EVENING HOURS WITH A DRY AIRMASS AND
LIGHT WINDS COMBINING TO PRODUCE NEARLY IDEAL CONDITIONS FOR
RADIATIONAL COOLING. FROST MAY BE WIDESPREAD ESPECIALLY ACROSS THE
NORTH ON SUNDAY MORNING WITH A ISOLATED SPOTS BELOW FREEZING.

HIGH PRESSURE WILL MOVE EASTWARD ON SUNDAY AND A TRANSITION TO
SOUTHERLY FLOW WILL BEGIN AS SURFACE PRESSURE FALLS OCCUR ACROSS
THE CENTRAL CONUS IN RESPONSE TO BROAD UPPER-LEVEL HEIGHT FALLS.
THE EASTERN EXTENT OF STRONGER SOUTHWESTERLY MID-LEVEL WARM
ADVECTION COULD LEAD TO SHOWERS CLIPPING THE NORTHWEST COUNTIES ON
MONDAY INTO MONDAY NIGHT.

MODELS AGREE THAT A STRONG TROUGH WILL TAKE SHAPE BY ACROSS THE
PLAINS ON TUESDAY INTO WEDNESDAY...BUT THERE IS SIGNIFICANT
DISAGREEMENT REGARDING THE AMPLIFICATION AND PROGRESSION OF THIS
SYSTEM. BOTH THE GFS AND ECMWF HAVE TRENDED TOWARD A SLOWER
SOLUTION...BUT THE EXTREMELY AMPLIFIED/SLOW GFS SOLUTION LOOKS
PARTICULARLY ANOMALOUS AND SHOULD PROBABLY BE DISCARDED. THIS
FORECAST IS LARGELY BASED ON THE FASTER TIMING OF THE ECMWF WITH
THE  BRUNT OF THE RAINFALL AND POSSIBLE THUNDERSTORM ACTIVITY
OCCURRING ON WEDNESDAY INTO WEDNESDAY NIGHT. CONFIDENCE IN TIMING
AND SEVERE PARAMETERS IS TOO LOW TO MENTION SEVERE STORMS IN THE
HWO...BUT THE AGGRESSIVE MOISTURE ADVECTION AS DEPICTED BY THE
ECMWF...SUGGESTS THAT INSTABILITY WOULD BE SUFFICIENT FOR AT LEAST
A LOW-END DAMAGING WIND AND TORNADO THREAT ON WEDNESDAY. IF MODELS
SHIFT BACK TOWARD MORE OF AN OPEN WAVE/PROGRESSIVE TROUGH...AN
ELEVATED SEVERE THREAT WOULD BECOME MORE LIKELY.

87/GRANTHAM

&&

.AVIATION...
06Z TAF DISCUSSION.

THE SURFACE WINDS FINALLY SHIFTED AT KTOI AT 2Z AND THE DRY AIR IS
NOW FILTERING INTO THE AREA. THERE WAS A BRIEF MOMENT OF IFR BUT
THAT HAS SINCE ENDED AND WINDS SHOULD STAY BETWEEN 3 AND 6 KTS FOR
THE NIGHT. IF THE WINDS DIE DOWN FOR MORE THAN AN HOUR THERE IS A
POSSIBILITY OF A BRIEF DROP IN VIS BUT POSSIBILITY IS TOO LOW TO
INCLUDE IN THE TAFS FOR NOW. WINDY FROM THE NORTH AFTER 15Z
BETWEEN 10 AT 12KT WITH SOME GUSTS UP TO 18KT THEN WINDS CALM BACK
DOWN AFTER 00Z.

16

&&

.FIRE WEATHER...

COOLER AND DRIER CONDITIONS WILL CONTINUE INTO THE WEEKEND. RAIN
CHANCES WILL RETURN MIDWEEK AHEAD OF OUR NEXT SYSTEM. RELATIVE
HUMIDITY VALUES ARE NOT EXPECTED TO REACH CRITICAL THRESHOLDS
THROUGH THE FORECAST.

87

&&

.PRELIMINARY POINT TEMPS/POPS...
GADSDEN     60  32  59  31  60 /   0   0   0   0   0
ANNISTON    61  35  61  33  61 /   0   0   0   0   0
BIRMINGHAM  62  37  62  35  62 /   0   0   0   0   0
TUSCALOOSA  64  37  65  36  64 /   0   0   0   0   0
CALERA      63  37  62  36  63 /   0   0   0   0   0
AUBURN      64  38  60  36  62 /   0   0   0   0   0
MONTGOMERY  66  39  65  36  65 /   0   0   0   0   0
TROY        66  39  64  35  65 /   0   0   0   0   0

&&

.BMX WATCHES/WARNINGS/ADVISORIES...
FROST ADVISORY FROM MIDNIGHT TONIGHT TO 7 AM CST SATURDAY FOR
CALHOUN-CLAY-CLEBURNE-FAYETTE-JEFFERSON-LAMAR-PICKENS-RANDOLPH-
SHELBY-ST. CLAIR-TALLADEGA-TUSCALOOSA-WALKER.

FREEZE WARNING FROM MIDNIGHT TONIGHT TO 7 AM CST SATURDAY FOR
BLOUNT-CHEROKEE-ETOWAH-MARION-WINSTON.

&&

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE BIRMINGHAM AL
911 AM CST THU NOV 12 2015

ALZ011>015-017>050-131815-
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-
911 AM CST THU NOV 12 2015

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

.DAY ONE...OUTLOOK THROUGH TONIGHT.

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

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

TEMPERATURES BELOW FREEZING ARE POSSIBLE SATURDAY AND SUNDAY
MORNINGS...FOR UP TO 2 TO 3 HOURS...IN THE TYPICALLY COOLER
LOCATIONS AND VALLEYS ACROSS NORTH CENTRAL ALABAMA.

.SPOTTER INFORMATION STATEMENT...

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

08