802  
FXUS64 KBMX 230016  
AFDBMX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE BIRMINGHAM AL  
716 PM CDT SUN OCT 22 2017  
   
UPDATE
 
 
AVIATION DISCUSSION.  
 

 
   
SHORT TERM
 
 
THIS AFTERNOON THROUGH TONIGHT.  
 
THE MCV MOVING EASTWARD ALONG THE AL/MS COAST HAS STABILIZED THE  
AIR MASS ACROSS CENTRAL ALABAMA. THE NORTHERN PORTION OF THE RAIN  
SHIELD HAS DECREASED CONSIDERABLY EARLY THIS AFTERNOON AS THE MAIN  
ENERGY AND LIFT STAYS NEAR THE COAST. DO BOT FORESEE ANY NORTHWARD  
TRANSPORT OF THE MORE UNSTABLE AIR MASS THROUGH THIS EVENING, AND  
EXPECT LITTLE IF ANY THUNDERSTORM ACTIVITY ACROSS CENTRAL ALABAMA.  
THERE COULD STILL BE SOME ISOLATED STORMS LATER THIS EVENING AND  
OVERNIGHT AS THE MAIN FORCING ASSOCIATED WITH THE UPSTREAM TROF  
APPROACHES THE AREA. RADAR IMAGERY TO THE WEST OF ALABAMA SHOWS  
MAINLY SCATTERED SHOWER ACTIVITY. THIS ACTIVITY WILL LIKELY FILL  
IN AS THE SHORT WAVE TROF TRACKS EASTWARD, SO WILL CONTINUE WITH  
HIGH RAIN CHANCES OVERNIGHT. THE COLD FRONT OR WIND SHIFT SHOULD  
REACH THE AL/MS STATE LINE NEAR MIDNIGHT AND THE I-65 CORRIDOR  
AROUND 3 AM. THE BACK EDGE OF THE RAIN SHOULD BE NEAR THE SURFACE  
FRONT. RAINFALL AMOUNTS HAVE BEEN TRIMMED BACK CONSIDERABLY BASED  
ON AFFECTS FROM THE MCV AND LACK OF UPSTREAM CONVECTIVE ACTIVITY.  
 
58/ROSE  
 
   
LONG TERM
 
 
MONDAY THROUGH SUNDAY.  
 
MODELS ARE IN BETTER AGREEMENT WITH FASTER PROGRESSION OF THE  
UPPER TROUGH ON MONDAY. RAIN SHOULD COME TO AN END BEFORE NOON,  
AND A MILD AFTERNOON IS EXPECTED WITH SOME BREAKS IN THE CLOUDS.  
AN UPSTREAM SHORTWAVE WILL REINFORCE THE COLD ADVECTION REGIME ON  
TUESDAY INTO WEDNESDAY WITH AFTERNOON TEMPERATURES IN THE UPPER  
50S TO LOWER 60S IN THE NORTH ON WEDNESDAY.  
 
A TRANSITION TO WARMER CONDITIONS IS EXPECTED ON THURSDAY AND  
FRIDAY AS SOUTHERLY FLOW DEVELOPS IN RESPONSE TO A LARGE TROUGH  
FORMING IN THE WESTERN CONUS. MODEL SPREAD IS QUITE LARGE ON THE  
TIMING OF THE NEXT FRONT SOMETIME IN THE FRIDAY NIGHT THROUGH  
SUNDAY TIMEFRAME. OUR FORECAST LEANS MORE TOWARD THE SLOWER AND  
MORE CONSISTENT ECMWF WITH THE HIGHEST RAIN CHANCES CENTERED ON  
SATURDAY NIGHT.  
 
87/GRANTHAM  
 

 
   
AVIATION
 
 
00Z TAF DISCUSSION.  
 
AN AREA OF LIGHT TO MODERATE RAIN IS SPREADING SOUTHWEST TO  
NORTHEAST ACROSS MOST TERMINALS THIS EVENING. AN AREA OF BROKEN  
SHOWERS EXTENDS WESTWARD ACROSS EASTERN MS. ALL OF THIS ACTIVITY IS  
AHEAD OF THE COLD FRONT, CURRENTLY NEAR THE MISSISSIPPI RIVER.  
AIRMASS IS FAIRLY STABLE ACROSS THE LOCAL AREA, WITH NO LIGHTNING  
INDICATED IN THE LARGE AREA OF RAIN ACROSS SOUTH CENTRAL ALABAMA IN  
APPROX AN HOUR, AND HAVE REMOVED ANY TS WORDING FROM THE FORECAST.  
 
EXPECT A MIX OF RAIN/SHOWERS/FOG OVERNIGHT, AS THIS ACTIVITY  
CONTINUES TO MOVE ACROSS THE AREA, WITH VIS AND CIGS DROPPING TO  
MVFR THIS EVENING, MOSTLY WITHIN HEAVIER AREAS OF RAIN. IFR CIGS ARE  
POSSIBLE CLOSER TO AND BEHIND THE COLD FRONT LATER TONIGHT. WINDS  
COULD BE GUSTY THIS EVENING FROM THE SOUTHEAST, BEFORE DIMINISHING  
AND SHIFTING TO THE SOUTHWEST, AND THEN WEST EARLY MONDAY MORNING  
WITH THE APPROACH AND PASSING OF THE FRONT.  
 
14  
 

 
   
FIRE WEATHER
 
 
 
A COLD FRONT WILL MOVE THROUGH THE AREA TONIGHT, PROVIDING A  
WIDESPREAD SOAKING RAINFALL THROUGH MONDAY MORNING. DRY THROUGH THE  
REST OF THE WEEK. RELATIVE HUMIDITY VALUES SHOULD REMAIN ABOVE  
CRITICAL THRESHOLDS. THERE ARE NO FIRE WEATHER CONCERNS.  
 

 
   
PRELIMINARY POINT TEMPS/POPS
 
 
GADSDEN 64 67 46 66 39 / 100 70 10 0 10  
ANNISTON 65 69 47 67 39 / 100 70 10 10 10  
BIRMINGHAM 63 68 49 68 41 / 90 30 10 0 10  
TUSCALOOSA 61 69 49 69 41 / 80 20 10 0 10  
CALERA 63 68 48 67 41 / 90 30 10 0 10  
AUBURN 67 70 50 68 42 / 100 80 10 10 10  
MONTGOMERY 67 72 51 71 43 / 100 40 10 0 10  
TROY 68 72 51 70 42 / 100 60 10 0 10  
 

 
   
BMX WATCHES/WARNINGS/ADVISORIES/
 
 
NONE.  
 

 
 

 
 
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