788  
FXUS64 KMOB 271721  
AFDMOB  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE MOBILE AL  
1221 PM CDT TUE JUN 27 2017  
   
DISCUSSION
 
UPDATED FOR LATEST AVIATION DISCUSSION BELOW.  
 

 
   
AVIATION
 
 
18Z ISSUANCE...VFR CONDITIONS AND LIGHT EASTERLY FLOW PREVAILS  
THROUGH THE FORECAST PERIOD. A FEW ISOLATED SHOWERS AND STORMS ARE  
POSSIBLE ALONG THE COAST THIS AFTERNOON, WITH ANY ACTIVITY TAPERING  
OFF AFTER 28.00Z. /49  
 

 
   
PREV DISCUSSION
 
/ISSUED 546 AM CDT TUE JUN 27 2017/  
 
DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.  
 
AVIATION...  
12Z ISSUANCE...MOSTLY VFR THROUGH THE PERIOD AS SURFACE WINDS  
VEER FROM LIGHT NORTHEASTERLY TO MORE EASTERLY BY THIS TAF  
PERIOD'S END. MID AND HIGH CLOUDS WILL CONTINUE STREAMING ACROSS  
THE AREA. AN ISOLATED THUNDERSTORM IS POSSIBLE FROM 27.21 UTC TO  
28.01 UTC GENERALLY SOUTH OF THE I-10 CORRIDOR. /23 JMM  
 
PREV DISCUSSION... /ISSUED 349 AM CDT TUE JUN 27 2017/  
 
NEAR TERM /NOW THROUGH TUESDAY NIGHT/...EARLY THIS MORNING A STATIONARY  
FRONT WAS LOCATED OFFSHORE WITH DEVELOPING PRECIPITATION ALONG IT  
ACROSS SOUTHERN LA EAST TO WELL SOUTH OF THE ALABAMA COAST. LIGHT NE  
SURFACE WIND FLOW WAS IN PROGRESS. DEEP LAYER MOISTENING IS IN STORE  
NEXT TWO DAYS AS UPPER TROPOSPHERIC WAVE MOVES EAST OUT OF TX TODAY  
AND BEINGS TO REFLECT DOWN INTO THE MID-TROPOSPHERE. THIS HAPPENS IN  
THE WELL KNOW 'BREAK BETWEEN TWO RIDGES.' THE APPROACH OF THE WAVE  
EXCITES THE LOWER TROPOSPHERIC WINDS TO VEER TO A MORE SE DIRECTION  
BY TONIGHT. AS FAR AS THUNDERSTORM DEVELOPMENT TODAY, EXPECT THEM TO  
MOSTLY REMAIN OFFSHORE WITH THE EXCEPTION OF THE IMMEDIATE COAST.  
THE LIGHT E->NE BOUNDARY LAYER WIND FLOW WILL OPPOSE THE DEVELOPING  
SEABREEZE AND WITH THE MOISTURE RETURN, SO THERE MAY BE SOME VERY  
ISOLATED DEEP CONVECTION FROM 20Z-01Z, OR SO. ANY DEEP CONVECTION  
WILL DIMINISH DURING THE EARLY EVENING, BUT THUNDERSTORM COVERAGE  
WILL BE ABOVE AVERAGE HOWEVER OVER THE AL COASTAL WATERS TONIGHT AS  
RETURN FLOW BEGINS AND THE AFOREMENTIONED UPPER LOW SHEAR ZONE  
ORIENTS ITSELF FROM SSW TO NNE ACROSS OUR AREA. /23 JMM  
 
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...SURFACE HIGH  
PRESSURE OVER THE MID ATLANTIC STATES WILL SLOWLY MIGRATE OFFSHORE  
BY MID DAY WEDNESDAY. MOISTURE LEVELS BEGIN TO INCREASE WITH  
SOUTHERLY RETURN FLOW AROUND THE SOUTHWESTERN PERIPHERY OF THE  
SURFACE HIGH. ACCORDINGLY, POPS WILL INCREASE INTO THE CHANCE  
CATEGORY FOR WEDNESDAY AFTERNOON.  
 
SOUTHERLY FLOW WILL BE FIRMLY IN PLACE THURSDAY MORNING WITH  
INCREASING DEEP LAYER MOISTURE. PRECIPITABLE WATER VALUES WILL BE  
ABOVE TWO INCHES WITH SOME AREAS APPROACHING 2.2 INCHES. A SUBTLE  
WEAKNESS IN THE MID LEVEL HEIGHT FIELD BETWEEN A STRONG RIDGE OVER  
THE SOUTHWESTERN ATLANTIC AND ANOTHER OVER NORTHERN MEXICO WILL  
PROVIDE MODEST SUPPORT FOR UPWARD VERTICAL MOTION ACROSS THE AREA,  
WHICH, WHEN COMBINED WITH AMPLE DEEP LAYER MOISTURE, WILL RESULT  
IN LIKELY POPS FOR MOST AREAS THURSDAY AFTERNOON. SHOWERS AND  
STORMS WILL LIKELY BE ONGOING NEAR AND OFFSHORE THURSDAY MORNING  
AND WILL SPREAD INLAND AS THE DAY PROGRESSES. TEMPERATURES WILL BE  
HELD DOWN THURSDAY AFTERNOON DUE TO INCREASED COVERAGE OF SHOWERS  
AND STORMS AND ASSOCIATED CLOUD COVER, GENERALLY LOW 80S ARE  
EXPECTED WITH A FEW MID 80S ACROSS OUR NORTHERN COUNTIES WHERE  
STORM COVERAGE WILL BE SLIGHTLY REDUCED. LOW TEMPERATURES THURSDAY  
INTO FRIDAY WILL BE IN THE LOW 70S WITH MID 70S AT THE BEACHES.  
05/RR  
 
LONG TERM /FRIDAY THROUGH MONDAY/...NOT MUCH CHANGE ON THE LARGE  
SCALE PATTERN FOR FRIDAY WITH A CONTINUED WEAKNESS IN THE MID  
LEVEL HEIGHT FIELD NEAR THE AREA AND COPIOUS GULF MOISTURE IN  
PLACE. WILL SHOW LIKELY POPS FOR FRIDAY AFTERNOON INTO THE  
EVENING. COVERAGE SHOULD DECREASE A FEW HOURS AFTER SUNSET BUT  
SOME SHOWERS AND STORMS WILL BE POSSIBLE INTO THE OVERNIGHT.  
TEMPERATURES WILL BE SLIGHTLY WARMER ON FRIDAY WITH MID 80S ACROSS  
THE AREA. CONTINUED WARM OVERNIGHT TEMPS WITH LOW TO MID 70S  
EXPECTED.  
 
THE WEAKNESS BETWEEN THE TWO RIDGES WILL BEGIN TO FILL ON SATURDAY  
AND SUNDAY LEADING TO LOWER COVERAGE OF SHOWERS AND STORMS FOR THE  
WEEKEND. ABSENT MUCH IN THE WAY OF MID AND UPPER LEVEL SUPPORT,  
STORM INITIATION WILL LIKELY BE CLOSELY TIED TO MESOSCALE BOUNDARIES  
(GULF/BAY BREEZES AND OLD OUTFLOW BOUNDARIES FROM PREVIOUS  
CONVECTION). THIS PATTERN WILL CONTINUE INTO THE FIRST PART OF THE  
WORK WEEK WITH GENERALLY CLIMATOLOGICAL POPS EXPECTED. WITH  
DECREASED SHOWER AND STORM COVERAGE WE WILL SEE AN UPTICK IN  
AFTERNOON HIGH TEMPERATURES WITH MID TO UPPER 80S FOR MOST SATURDAY  
WITH PERHAPS A FEW 90S INLAND BY SUNDAY AND MONDAY AFTERNOONS.  
05/RR  
 
MARINE...TODAY A LIGHT NE WIND FLOW BECOMES MORE EASTERLY. BY  
EARLY WEDNESDAY, SURFACE WINDS WILL BECOME SOUTHERLY AND INCREASE  
AND SEAS WILL THEN ONCE AGAIN BUILD SOLIDLY TO AROUND 2 FEET  
WEDNESDAY NIGHT AND EARLY THURSDAY. ALSO SHOWER AND THUNDERSTORM  
COVERAGE INCREASES FROM THE SOUTHWEST. WAVES CONTINUE AROUND 2  
FEET THURSDAY WITH AN INCREASE TO 3 FEET IN OUR SOUTHWESTERN ZONES  
LATE THURSDAY INTO FRIDAY WITH CONTINUED SOUTHERLY FLOW. GREATEST  
COVERAGE OF SHOWERS AND STORMS WILL COME THURSDAY AND FRIDAY  
BEFORE BACKING OFF MODESTLY FOR THE WEEKEND PERIOD. 23/05  
 

 
   
MOB WATCHES/WARNINGS/ADVISORIES
 
 
AL...NONE.  
FL...NONE.  
MS...NONE.  
GM...NONE.  

 
 

 
 
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:  
HTTP://WEATHER.GOV/MOB  
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

The Nexlab AL Page
The Nexlab FL Page
The Nexlab MS Page Main Text Page