161  
FXUS64 KBMX 201143  
AFDBMX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE BIRMINGHAM AL  
643 AM CDT SAT APR 20 2019  
   
UPDATE
 
 
FOR 12Z AVIATION.  
 

 
   
SHORT TERM
 
 
TODAY AND TONIGHT.  
 
AS THE UPPER LOW SWINGS THROUGH THE AREA THIS MORNING, WE WILL SEE  
THE CLEARING LINE LINE REACH THE WESTERN COUNTIES BY SUNRISE AND  
THEN GET TO THE I-65 CORRIDOR BY 9 AM, WITH ONLY SOME LINGERING  
RAIN IN THE FAR NORTHEAST THROUGH THE AFTERNOON. HIGHS WILL BE IN  
THE UPPER 50S IN THE NORTHEAST WITH LOW TO MID 60S ELSEWHERE.  
THEREAFTER, CLEAR SKIES AND A COOL OVERNIGHT PERIOD ARE EXPECTED.  
TEMPERATURES WILL DROP INTO THE UPPER 30S IN THE NORTHEAST AND  
COOLER LOCATIONS, WITH LOW 40S ELSEWHERE.  
 
16  
   
LONG TERM
 
 
SUNDAY THROUGH WEDNESDAY.  
 
THE NEGATIVE HEIGHT ANOMALY PREVIOUSLY RESPONSIBLE FOR THE LAST  
ROUND OF SEVERE WEATHER WILL BE MAKING ITS EXIT OFF THE EAST COAST  
BY SUNDAY MORNING. UPSTREAM NORTHWESTERLY FLOW ALOFT WILL OVERTAKE  
MUCH OF THE DEEP SOUTH AS A RESULT, WITH AN ACCOMPANYING ~1020 MB  
SURFACE HIGH PRESSURE CENTERED ACROSS CENTRAL ALABAMA. THIS PERIOD  
OF STABLE WEATHER SHOULD PERSIST INTO MID-WEEK WITH A GENERAL  
EASTWARD PROGRESSION OF THE SURFACE HIGH. RETURN FLOW IS EXPECTED  
TO MAKE A NOTICABLE RETURN BY TUESDAY WITH HIGH PRESSURE OFF THE  
CAROLINA COAST. AS A RESULT, WARM TEMPERATURES & INCREASING  
DEWPOINTS WILL SIGNAL THE DEVELOPMENT OF A MID/UPPER-LEVEL RIDGE  
ACROSS THE SOUTHEAST. MEANWHILE, A COMPLEX JET STREAM FEATURING A  
SPLIT-FLOW CONFIGURATION SETS UP ACROSS THE CONUS. BY WEDNESDAY  
EVENING THIS UPPER-LEVEL PATTERN IS PROGGED TO ADVANCE A SOUTHERN  
STREAM SHORTWAVE FROM THE SOUTHERN ROCKIES INTO THE SOUTHERN  
PLAINS.  
 
TEMPERATURES WILL UNDERGO A WARMING TREND INTO MID-WEEK. SUNDAY  
AFTERNOON HIGHS ARE FORECAST TO RANGE IN THE LOW TO UPPER 70S, WITH  
UPPER 70S TO MID 80S EXPECTED BY WEDNESDAY AFTERNOON. HAVE HELD OFF  
ON UPPER 80S FOR WEDNESDAY AS EFFECTS FROM THE PROGGED SHORTWAVE MAY  
STAVE OFF WARMER TEMPERATURES WITH CLOUD COVER INCREASES AND  
HEIGHT FALLS. ON THE COOLER SIDE OF THINGS, MONDAY MORNING MIGHT  
BE CHILLY FOR SOME AS MID 40S TO LOWER 50S ARE EXPECTED TO START  
OFF THE WORK WEEK, THOUGH TEMPERATURES SHOULD WARM QUICKLY UNDER  
SUNNY SKIES BY THE AFTERNOON. NO MENTIONABLE RAIN CHANCES ARE  
FORECAST SUNDAY THROUGH WEDNESDAY AFTERNOON AT THIS TIME.  
 
THURSDAY AND FRIDAY.  
 
THE UPCOMING MID-LEVEL DISTURBANCE WILL CERTAINLY HAVE SOME SORT OF  
IMPACT ON WEATHER ACROSS THE AREA THURSDAY/FRIDAY. AS EXPECTED, A  
BROAD INCREASE IN THETA-E FIELDS DOWNSTREAM OF THE TROUGH WITH  
ASSOCIATED SYNOPTIC ASCENT FAVORS INCREASING POPS FOR MANY ACROSS  
THE GULF COAST. HOWEVER, VARYING SOLUTIONS WITH REGARDS TO THE  
EVOLUTION OF THE SHORTWAVE STILL EXISTS, THUS WITH MANY OTHER  
SUBSEQUENT FORECAST DETAILS FOR THIS PERIOD. WITH ANY QUALITY  
MOISTURE RETURN AND AFTERNOON HEATING THURSDAY, A CHANCE OF  
THUNDERSTORMS EXISTS GIVEN MARGINAL SHEAR PROFILES (20-30 KTS 0-6 KM  
BULK SHEAR) FROM THE UPSTREAM TROUGH/MID-LEVEL JET MAX. SINCE EXACT  
TIMING AND STRENGTH OF MOISTURE RETURN IN THE BOUNDARY LAYER WILL  
DICTATE WHERE THESE BETTER CHANCES WILL RESIDE, HAVE BROAD BRUSHED A  
SLIGHT CHANCE ACROSS THE ENTIRE AREA GIVEN CURRENT UNCERTAINTIES.  
TAKING CURRENT DATA AT FACE VALUE WOULD SUGGEST AREAS ACROSS THE  
WEST STAND A BETTER CHANCE AT SEEING A THUNDERSTORM THURSDAY  
AFTERNOON/EVENING, WITH BETTER AREA-WIDE COVERAGE OVERNIGHT FRIDAY  
AND INTO FRIDAY MORNING. DUE TO CURRENT PROGGED SOUTHWARD POSITIONING  
OF THE TROUGH HOWEVER, MOST CONVECTION MAY REMAIN ALONG THE GULF  
COAST WHERE THE BEST LOW-LEVEL JET AND DEEP-LAYER MOISTURE IS  
LIKELY. THIS SCENARIO USUALLY KEEPS INLAND AREAS MORE STABLE FROM  
RESULTANT DOWN-SHEAR CLOUD COVER & LIMITED INSTABILITY. THOUGH RAIN  
SHOWERS & THUNDERSTORMS COULD BE EXPECTED THURSDAY NIGHT INTO  
FRIDAY, NO ORGANIZED SEVERE WEATHER THREAT IS FORECAST UNTIL A  
BETTER AND/OR CONSISTENT SIGNAL APPEARS, WHICH IS NOT THE CASE  
CURRENTLY.  
 
40/SIZEMORE  
 

 
   
AVIATION
 
 
12Z TAF DISCUSSION.  
 
THERE IS SOME IMPROVEMENT OUT THERE ALREADY. TCL/BHM/EET/AND MGM  
HAVE ALREADY GONE TO VFR AND WILL LIKELY GET TO ANB/ASN BY 15Z  
AND TOI BY 14Z. MAY STAY CLOUDY AT ANB A LITTLE LONGER BUT LOOK  
FOR GENERALLY VFR THERE AS WELL. WINDS WILL BE BRISK TODAY BUT  
WILL CALM AFTER 00Z.  
 
16  
 

 
   
FIRE WEATHER
 
 
SURFACE WINDS REMAIN BREEZY THROUGH THE AFTERNOON WITH PEAK  
SUSTAINED SPEEDS AROUND 10-15 KNOTS WITH GUSTS AROUND 15-20 KNOTS.  
20-FOOT WINDS LOOK TO AVERAGE AROUND 8-13 KNOTS. PERIODS OF MIST  
AND RAIN SHOWERS SHOULD DECREASE IN COVERAGE BY THE LATE MORNING  
WITH ONLY SOME LINGERING ACTIVITY ACROSS NORTHEAST ALABAMA.  
CLOUDS WILL GRADUALLY CLEAR WEST-TO-EAST THIS AFTERNOON, HOLDING  
ON LONGEST ACROSS THE EAST/NORTHEAST ALABAMA. DRIER AIR WITH RH  
VALUES IN THE 30 PERCENT RANGE ARE EXPECTED TO ARRIVE ACROSS THE  
WESTERN HALF OF THE STATE BY THIS AFTERNOON, WITH VALUES IN THE  
30S AREA-WIDE SUNDAY AFTERNOON.  
 

 
   
PRELIMINARY POINT TEMPS/POPS
 
 
GADSDEN 57 40 75 47 80 / 60 0 0 0 0  
ANNISTON 58 40 76 48 81 / 50 0 0 0 0  
BIRMINGHAM 62 44 78 51 82 / 20 0 0 0 0  
TUSCALOOSA 66 41 78 50 81 / 10 0 0 0 0  
CALERA 63 42 76 50 80 / 10 0 0 0 0  
AUBURN 60 43 74 50 80 / 20 0 0 0 0  
MONTGOMERY 66 42 77 50 82 / 10 0 0 0 0  
TROY 65 44 77 49 81 / 0 0 0 0 0  
 

 
   
BMX WATCHES/WARNINGS/ADVISORIES/
 
 
NONE.  
 

 
 

 
 
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