173  
FXUS64 KBMX 282358  
AFDBMX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE BIRMINGHAM AL  
658 PM CDT FRI APR 28 2017  
   
UPDATE
 
 
FOR 00Z AVIATION.  
 

 
   
SHORT TERM
 
 
REST OF THIS AFTERNOON THROUGH SATURDAY.  
 
CENTRAL ALABAMA WILL BE UNDER THE INFLUENCE OF A 500MB RIDGE  
CENTERED JUST OFFSHORE OF THE SOUTHEASTERN U.S., OF WHICH IS  
FORECAST TO AMPLIFY A BIT AS A 500MB TROUGH DEEPENS OVER THE  
SOUTHWESTERN U.S. WE'LL HAVE A VARIED PRESENCE OF CLOUDS TODAY  
THROUGH SATURDAY, WITH RAIN-FREE WEATHER DOMINATING THE PERIOD;  
HOWEVER, IT'S PLAUSIBLE THAT WE COULD HAVE A STRAY SHOWER/WEAK  
PULSE T'STORM ACROSS CENTRAL ALABAMA DURING THE HOURS OF PEAK  
DAYTIME HEATING (BOTH TODAY AND SATURDAY). THE CHANCE OF SUCH  
ACTIVITY IS 'SLIM'/ABOUT 20%.  
 
HIGH TEMPERATURES TODAY SHOULD MAX IN THE MID-UPPER 80S, SLIGHTLY  
WARMER ON SATURDAY WITH UPPER 80S BECOMING MORE COMMON + A FEW  
90S POSSIBLE (F). WITH DEW POINTS IN THE MID-UPPER 60S (F),  
THERE'LL BE A BIT OF A MUGGY FEEL TO THE AIR MASS. ADDITIONALLY,  
WE'VE HAD WIND GUSTS THIS AFTERNOON IN THE 15-20 KNOT RANGE ACROSS  
THE REGION AND, WITH A SLIGHTLY TIGHTER UPSTREAM PRESSURE  
GRADIENT, WIND GUSTS OF 20-25 KNOTS ARE PROBABLE ON SATURDAY  
(PERHAPS AN INSTANCE OR TWO JUST OVER 25-KNOTS) POST EROSION OF  
THE MORNING INVERSION GIVEN WARMTH AND ANTICIPATED MIXING OF LOW-LEVEL  
SOUTHERLY FLOW. THE BREEZIEST OF WINDS WILL EXIST WITH CLOSER  
PROXIMITY TO THE MISSISSIPPI RIVER, ARCHING TOWARD THE GULF COAST.  
GIVEN PROJECTED MAX GUSTS NUMBERS, WE'RE BELOW WIND ADVISORY  
CRITERIA (35-KNOTS).  
 
AN ACTIVE WEATHER PATTERN IS SET TO EVOLVE AS WE HEAD INTO LATE  
SUNDAY AFTERNOON, CONTINUING INTO THE NIGHTTIME HOURS -- OUTLINED  
BELOW.  
 
89^GSATTERWHITE  
   
LONG TERM
 
 
SUNDAY THROUGH THURSDAY.  
 
CONDITIONS WILL DETERIORATE LATE IN THE AFTERNOON AND INTO THE  
EVENING AS A QLCS MARCHES ACROSS MISSISSIPPI AND INTO ALABAMA.  
INSTABILITY IN ADVANCE OF THE QLCS SHOULD BE CONFINED TO A  
RELATIVELY NARROW CORRIDOR WITH SBCAPE AS HIGH AS 1200 J/KG ACROSS  
OUR WEST AND SLOWLY DIMINISHING WITH EASTWARD EXTENT THROUGH THE  
EVENT. A STRONG LOW-LEVEL JET OF 45-60KT WILL SUPPORT A POTENTIAL  
FOR BRIEF EMBEDDED TORNADOES AND DAMAGING WIND GUSTS. DIRECTIONAL  
SHEAR IN THE EARLY PART OF THE EVENT APPEARS RATHER POOR WITH  
SOUTH-SOUTHWEST WINDS AT 500MB. THESE VECTORS ARE EXPECTED TO  
BECOME MORE WESTERLY AROUND 06Z MONDAY, WHICH COULD ACTUALLY  
ENHANCE THE THREAT ACROSS OUR CENTRAL AND EASTERN COUNTIES THROUGH  
12Z MONDAY AS THE QLCS GAINS MOMENTUM. FOR NOW THE BEST CHANCE OF  
SEVERE WEATHER WILL BE ADVERTISED ACROSS THE WEST, BUT COULD BE  
EXPANDED EASTWARD.  
 
DRY CONDITIONS WILL RETURN FOR TUESDAY BEHIND THE FRONT, BUT THIS  
MAY BE SHORT-LIVED AS DISTURBANCES IN THE NORTHERN AND SOUTHERN  
STREAMS COMBINE ON WEDNESDAY. WE COULD BE LOOKING AT AN EXTENDED  
PERIOD OF RAIN WEDNESDAY AFTERNOON THROUGH THURSDAY DUE TO THE  
SLOW PROGRESSION OF A POSITIVELY-TILTED NORTHERN STREAM TROUGH.  
 
87/GRANTHAM  
 

 
   
AVIATION
 
 
00Z TAF DISCUSSION.  
 
SOMEWHAT SIMILAR CONDITIONS TO LAST NIGHT EXPECTED OVERNIGHT.  
SOME HIGH CLOUDS WILL BE AROUND, BUT EXPECTED THE MVFR CEILINGS  
DEVELOPING RATHER QUICKLY AROUND 8-10Z. A FEW SPOTS COULD ONCE  
AGAIN EXPERIENCE IFR FOR A HOUR OR SO AND HAVE ADDED SOME MENTION.  
DO NOT THINK FOG WILL BE AN ISSUE ANYWHERE TONIGHT AS THE WINDS  
WILL STAY ABOVE 6KTS AT MOST TERMINALS. THE PRESSURE GRADIENT  
BETWEEN A HIGH TO THE EAST AND A DEVELOPING LOW TO THE WEST WILL  
PRODUCE GUSTY WINDS FOR AN HOUR OR SO THIS EVENING AND AGAIN ON  
SATURDAY. WINDS WILL GENERALLY BE SOUTHEAST TO SOUTH THROUGHOUT.  
 
75  
 

 
   
FIRE WEATHER
 
 
 
RAIN CHANCES WILL REMAIN LOW THROUGH SUNDAY AFTERNOON BEFORE  
INCREASING RAPIDLY SUNDAY NIGHT INTO EARLY MONDAY. THERE ARE NO  
FIRE WEATHER CONCERNS AT THIS TIME.  
 

 
   
PRELIMINARY POINT TEMPS/POPS
 
 
GADSDEN 68 88 69 86 61 / 10 20 10 20 90  
ANNISTON 68 88 69 86 63 / 10 20 10 20 90  
BIRMINGHAM 70 89 70 87 60 / 10 20 10 40 90  
TUSCALOOSA 71 90 70 86 58 / 10 20 10 60 90  
CALERA 70 88 69 86 60 / 10 20 10 40 90  
AUBURN 69 87 69 84 66 / 10 20 10 20 70  
MONTGOMERY 71 90 68 88 65 / 10 20 10 20 90  
TROY 70 89 69 86 67 / 10 20 10 20 90  
 

 
   
BMX WATCHES/WARNINGS/ADVISORIES/
 
 
NONE.  
 

 
 

 
 
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