289  
FXUS64 KBMX 160539  
AFDBMX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE BIRMINGHAM AL  
1239 AM CDT MON JUL 16 2018  
   
UPDATE
 
 
FOR 06Z AVIATION.  
 

 
   
SHORT TERM
 
 
PRECIPITABLE WATER VALUES AT 2 INCHES OR MORE ACROSS MUCH OF  
CENTRAL ALABAMA, BUT THERE IS A GRADIENT IN THE MOISTURE FROM WEST  
TO EAST. THERE IS AN AXIS OF HIGHER MICROBURST POTENTIAL AND HAIL  
POTENTIAL FROM NEAR LEE COUNTY, TO JEFFERSON COUNTY, TO MARION  
COUNTY. THIS AXIS ALSO COINCIDES WITH SBCAPE MAXIMUM NEAR 4000.  
NUMEROUS OUTFLOW BOUNDARIES OF VARYING EXTENT ARE CONVERGING INTO  
THIS ZONE FROM ALL DIRECTIONS. THEREFORE, INCREASED RAIN CHANCES  
FOR ALL OF WESTERN AREAS AND NEAR THIS AXIS THE REMAINDER OF THE  
AFTERNOON HOURS AND INTO THE FIRST COUPLE OF HOURS THIS EVENING.  
 
850-300 WINDS ARE VERY WEAK OVER THE AREA, THEREFORE STORM  
MOVEMENT IS NEARLY STATIONARY. THE STORMS ARE PROPAGATING DUE TO  
THE NUMEROUS BOUNDARIES AND WILL TEND TO MOVE EASTWARD OR  
SOUTHWARD WITH TIME, BUT SOME VARIATIONS CERTAINLY EXPECTED. THE  
STRONGEST STORMS WILL BE CAPABLE OF PRODUCING WIND GUSTS UP TO 45  
MPH AND RAINFALL OF 1 TO 3 INCHES IN A SHORT PERIOD OF TIME.  
COVERAGE WILL DIMINISH WITH THE LOSE OF DAYTIME HEATING THROUGH  
THE EVENING HOURS.  
 
75  
 
   
LONG TERM
 
 
MONDAY THROUGH SATURDAY.  
 
NORTHWEST FLOW WILL DEVELOP ALOFT ON MONDAY WHILE LOW-LEVEL FLOW  
BECOMES MORE CYCLONIC. THIS WILL OCCUR AS A DEEP TROUGH MOVES  
THROUGH EASTERN CANADA AND THE GREAT LAKES AND RIDGING BEGINS TO  
BUILD OVER THE WESTERN CONUS. A COLD FRONT WILL BEGIN TO MOVE INTO  
THE MID-SOUTH/OHIO VALLEY REGIONS. HIGH PWATS AROUND 2 TO 2.2  
INCHES WILL REMAIN IN PLACE ESPECIALLY ACROSS THE SOUTHERN  
COUNTIES, WITH ANOTHER PRE-FRONTAL AXIS OF HIGH PWATS SINKING DOWN  
INTO THE NORTHWEST COUNTIES DURING THE LATE AFTERNOON. EXPECT  
ANOTHER DAY OF HOT AND HUMID CONDITIONS WITH HEAT INDEX VALUES  
CLIMBING TO AROUND 105 BY MIDDAY, BEFORE HIGH COVERAGE OF  
SHOWERS/STORMS CAUSES SOME RELIEF IN THE AFTERNOON. LOCALLY HEAVY  
RAINFALL/LOCALIZED FLOODING WILL REMAIN POSSIBLE. BEST COVERAGE  
MAY END UP BEING IN THE NORTHWEST COUNTIES WHERE CLUSTERS OF PRE-  
FRONTAL STORMS MAY MOVE IN FROM THE NORTHWEST. THIS IS ALSO WHERE  
THE BEST CHANCE OF SOME STRONGER STORMS WITH GUSTY WINDS WILL BE  
GIVEN AN AXIS OF RELATIVELY DRY AIR ALOFT BETWEEN THE TWO MOISTURE  
AXES, BUT MID-LEVEL LAPSE RATES AND SHEAR WILL REMAIN VERY WEAK.  
STILL SOME SIGNALS OF A POSSIBLE MCS OR TWO DEVELOPING MONDAY  
NIGHT OR AT LEAST A FEW CLUSTERS OF STORMS. WITH TIMING IN THE  
MODELS RANGING FROM EARLY EVENING TO AFTER MIDNIGHT, WILL KEEP  
LIKELY POPS IN ACROSS THE NORTH ALL NIGHT LONG.  
 
OUTFLOW BOUNDARIES FROM MONDAY NIGHT'S CONVECTION WILL LIKELY PLAY  
A ROLE ON TUESDAY'S FORECAST. HIGHEST CONFIDENCE IN WIDESPREAD  
RAIN CHANCES WILL BE ACROSS THE SOUTHERN COUNTIES NEAR AN UPPER  
SHEAR AXIS. IT'S POSSIBLE THAT OUTFLOW COULD STABILIZE THE  
NORTHERN COUNTIES, BUT THE MAIN FRONT/THETA-E GRADIENT/PWAT  
GRADIENT WILL REMAIN NORTH OF THE AREA EVEN AS THE SURFACE  
TROUGH/WIND SHIFT GRADIENT MOVES THROUGH. THESE FACTORS WILL  
HOPEFULLY KEEP HEAT INDEX VALUES BELOW 105. LOCALLY HEAVY  
RAINFALL/LOCALIZED FLOODING REMAINS A THREAT.  
 
POP/DEW POINT FORECAST FOR WEDNESDAY/THURSDAY WILL HINGE ON  
EXACTLY WHERE THE FRONT STALLS OUT. MODELS CONTINUE TO VARY FROM  
RUN TO RUN AND BETWEEN EACH OTHER. HIGHEST CONFIDENCE IN RAIN  
CHANCES WILL BE ACROSS THE SOUTH ON WEDNESDAY AND SOUTHEAST ON  
THURSDAY. A WAVE OF LOW PRESSURE ALSO LOOKS TO DEVELOP ALONG THE  
FRONT BY THURSDAY AND MOVE UP THE EAST COAST, WHILE A SHORTWAVE  
BEGINS TO APPROACH FROM THE NORTHWEST.  
 
UPPER-LEVEL PATTERN WILL CONTINUE TO AMPLIFY FRIDAY THROUGH THE  
WEEKEND AS RIDGING STRENGTHENS NEAR THE FOUR CORNERS AND AN  
ANOMALOUS UPPER LOW MOVES INTO THE GREAT LAKES/OHIO VALLEY  
REGION. THIS WILL RESULT IN THE POTENTIAL FOR MCSS/ORGANIZED  
STORMS. WILL NEED TO MONITOR THE POTENTIAL FOR SEVERE STORMS GIVEN  
FORECAST MID-LEVEL LAPSE RATES/BULK SHEAR VALUES, BUT CONFIDENCE  
IS LOW THIS FAR OUT.  
 
32/DAVIS  
 

 
   
AVIATION
 
 
06Z TAF DISCUSSION.  
 
CONTINUED TO LEAN HEAVILY TOWARD PERSISTENCE WITH THIS ISSUANCE.  
EXPECT MVFR/IFR CLOUDS AND CEILINGS AT SEVERAL LOCATIONS AROUND  
SUNRISE. MONDAY WILL BE ANOTHER DAY WHERE NUMEROUS SHOWERS AND  
THUNDERSTORMS REDEVELOP. THE TIMING WILL BE DEPENDENT UPON THE  
CLOUD COVER DECREASE IN THE MORNING AND HOW FAST IT HEATS UP.  
 
16  
 

 
   
FIRE WEATHER
 
 
ABOVE NORMAL COVERAGE OF MAINLY AFTERNOON AND EARLY EVENING  
SHOWERS AND THUNDERSTORMS IS EXPECTED THROUGH AT LEAST TUESDAY AS  
A WEAK FRONT MOVES TOWARDS THE AREA. LOCALIZED FOG WILL BE  
POSSIBLE EACH MORNING WHERE RAINFALL OCCURS DURING THE PREVIOUS  
AFTERNOON AND EVENING. THERE ARE NO FIRE WEATHER CONCERNS.  
 

 
   
PRELIMINARY POINT TEMPS/POPS
 
 
GADSDEN 90 71 90 70 89 / 70 60 60 40 20  
ANNISTON 89 72 89 71 90 / 70 60 70 50 30  
BIRMINGHAM 91 74 90 73 90 / 70 60 70 50 40  
TUSCALOOSA 94 75 92 74 93 / 70 60 80 40 40  
CALERA 89 72 89 72 90 / 70 60 80 50 40  
AUBURN 88 72 87 72 88 / 70 50 80 60 60  
MONTGOMERY 92 74 91 74 91 / 70 50 80 60 60  
TROY 90 74 89 74 89 / 70 50 80 60 70  
 

 
   
BMX WATCHES/WARNINGS/ADVISORIES/
 
 
NONE.  
 

 
 

 
 
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