857  
FXUS64 KMOB 221006  
AFDMOB  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE MOBILE AL  
506 AM CDT MON SEP 22 2014  
   
SHORT TERM (TODAY THROUGH WEDNESDAY NIGHT)
 
THE LONG ANTICIPATED  
FRONT WILL BE AT OUR NORTHERN DOORSTEP AS OF AROUND 12Z AND SWEEPING  
THROUGH OUR NECK OF THE WOODS THIS AFTERNOON. THE 1000-500 MB HALF OF  
THE ATMOSPHERE WILL BE SOMEWHAT CONDUCIVE TO SCATTERED CONVECTION  
WITH LIFTED INDEX -2 TO -3...CAPE NEAR 1800 J/KG...AND PRECIPITABLE  
WATER ABOUT 1.5 INCHES.  
 
UPPER FLOW FROM THE NORTHWEST...20 TO 40 KNOTS WITH EMBEDDED  
PERTURBATIONS...WILL CONTINUE HELP PUSH THE FRONT OVER THE GULF. A  
STRONG SURFACE HIGH OVER THE MID MISSISSIPPI VALLEY IS MOVING  
SOUTHEAST BEHIND THIS FRONT BRINGING COOLER DRY AIR BEHIND IT.  
 
HIGH TEMPERATURES TODAY SHOULD BE IN THE MID 80S IN THE FAR NORTH  
WHICH WILL ALREADY HAVE EXPERIENCED FRONTAL PASSAGE AND UPPER 80S  
CLOSER TO THE COAST. RESPECTIVE TO MONTHLY AVERAGES IT IS ABOUT  
NORMAL. LOWS WILL BE BELOW CLIMATOLOGICAL NORMAL VALUES...MID 50S  
INLAND AND UPPER 50S MOVING TO WITHIN 50 OR SO MILES OF THE COAST AND  
LOWER 60S SOUTH OF I-10.  
 
RAIN CHANCES WILL BE PRACTICALLY NIL AFTER THE FRONT PASSES BY. THE  
LIFTED INDEX WILL EXCEED PLUS 2.5 TO 3 DEGREES C...SUFFICIENTLY  
STABLE TO SUPPRESS VIRTUALLY ALL CONVECTION TONIGHT. PRECIPITABLE  
WATER BELOW 0.75 INCHES. 77/BD  
 
AUTUMN WILL START OUT ON A REFRESHING NOTE FOR THE TUESDAY AND  
WEDNESDAY TIME FRAME. LOW LEVEL NORTHEAST FLOW WILL BE ESTABLISHED AS  
A LARGE SURFACE HIGH CENTERED OVER THE MIDWEST INTO THE MID ATLANTIC  
ON TUESDAY SHIFTS EAST INTO NEW ENGLAND BY WEDNESDAY. PRECIPITABLE  
WATER VALUES WILL BE VERY LOW...AVERAGING 0.50-0.75 INCHES WHICH IS 2  
STANDARD DEVIATIONS BELOW NORMAL FOR THIS TIME OF YEAR. THIS WILL  
KEEP RAIN OUT OF THE FORECAST WITH HIGHS NEAR NORMAL IN THE LOW TO  
MID 80S. LOWS BOTH TUESDAY AND WEDNESDAY NIGHTS WILL RANGE FROM THE  
UPPER 50S TO NEAR 60 ALONG AND NORTH OF HIGHWAY 84....WITH MID 60S  
ALONG THE I-10 CORRIDOR. 34/JFB  
   
LONG TERM (THURSDAY THROUGH SUNDAY)
 
A REX BLOCK IN THE MID TO  
UPPER LEVELS (WEAK UPPER LOW OVER THE SOUTHEAST/SOUTHERN APPALACHIANS  
AND STRONG RIDGING ACROSS THE WESTERN ATLANTIC INTO THE NORTHEAST) IS  
NOW FORECAST TO PERSIST THROUGH THE END OF THE WEEK. AT THE  
SURFACE...LOW LEVEL FLOW WILL REMAIN NORTHEASTERLY. PRECIPITABLE  
WATERS ARE FORECAST TO REMAIN AT AN INCH OR LOWER ACROSS THE REGION  
ON THURSDAY...AND AS A RESULT HAVE REMOVED RAIN CHANCES FOR  
THURSDAY/THURSDAY NIGHT. BY FRIDAY...THE 850-700 MB FLOW WILL BECOME  
MORE EAST TO PERHAPS SOUTHEAST...TAPPING INTO DEEPER ATLANTIC  
MOISTURE AND SPREADING IT INTO THE EASTERN PARTS OF THE FORECAST  
AREA. THE MOISTURE MAY BE SUFFICIENT ENOUGH TO RESULT IN AN ISOLATED  
SHOWER OR STORM DURING THE DAY FRIDAY EAST OF I-65...BUT DRY  
CONDITIONS WILL LIKELY PREVAIL OVER MOST AREAS. HOWEVER...WE WILL SEE  
AN INCREASE IN CLOUD COVER BY THE END OF THE WEEK.  
 
WHILE MID LEVEL RIDGING WILL REMAIN STRONG OVER THE SOUTHWEST  
ATLANTIC OVER THE WEEKEND...GUIDANCE IS COMING INTO BETTER AGREEMENT  
ON A SIGNIFICANT TROUGH DEVELOPING OVER THE SOUTHERN PLAINS INTO THE  
WESTERN GULF BY SATURDAY AND MOVING EAST BY SUNDAY. THIS RESULTS IN A  
DEEP SOUTHERLY FETCH OF TROPICAL MOISTURE MOVING NORTH INTO THE  
FORECAST AREA WITH PRECIPITABLE WATERS CLIMBING TO OR ABOVE 2 INCHES.  
THIS ALL TRANSLATES INTO INCREASING RAIN CHANCES AS WE GO THROUGH THE  
WEEKEND...WITH THE HIGHEST RAIN CHANCES CURRENTLY CENTERED AROUND  
SUNDAY. IT SHOULD BE NOTED THAT THE ECMWF IS MUCH DEEPER AND SLOWER  
WITH THE EASTWARD PROGRESSION OF THIS MID LEVEL TROUGH AND CONTINUES  
TO DEVELOP AN INVERTED TROUGH OVER THE CENTRAL GULF WITH A WEAK SFC  
LOW DEVELOPING ALONG THE TROUGH AXIS AND MOVING NORTH INTO THE NORTH  
CENTRAL GULF COAST BY SUNDAY AFTERNOON. THE STRENGTH OF THE ECMWF  
SYSTEM WOULD RESULT IN THE POTENTIAL FOR A MORE ORGANIZED HEAVY  
RAINFALL EVENT...SOMETHING IT HAS BEEN RATHER PERSISTENT IN  
INDICATING. WILL CONTINUE TO MONITOR THIS POTENTIAL CLOSELY THROUGH  
THE COURSE OF THE WEEK. HIGHS WILL REMAIN NEAR NORMAL THROUGH THE  
EXTENDED RANGE. LOWS MODERATE TO SLIGHTLY ABOVE SEASONAL LEVELS  
OVER THE WEEKEND DUE TO THE INCREASINGLY TROPICAL AIRMASS. 34/JFB  
 

 
   
AVIATION
 
 
12Z ISSUANCE  
VFR CONDITIONS WILL PREVAIL THROUGH MUCH OF THE PERIOD UNTIL A WEAK  
COLD FRONT TRAVERSES THE REGION TODAY. AS OF 12Z WE EXPECT A BROKEN  
O OVERCAST DECKS AROUND 035 AND 080 TO BE ALONG AND 40 MILES EITHER  
SIDE OF A LINE FROM WAYNESBORO MISSISSIPPI TO NEAR FORT DEPOSIT  
ALABAMA. SOUTHEAST MOVEMENT OF THE FRONT ABOUT 20 TO 25 KNOTS WOULD  
BRING IT NEAR THE COAST ALONG A LINE FROM PASCAGOULA MISSISSIPPI TO  
NEAR OPP ALABAMA BY MID AFTERNOON TODAY. ISOLATED TO SCATTERED  
SHOWERS AND THUNDERSTORMS ARE EXPECTED AS THE FRONT APPROACHES THIS  
AFTERNOON AND WE ARE CONSIDERING THIS TO BE INCLUDED AS A 2 TO 3  
HOUR PROB30 GROUP AT THE TERMINALS. 77/BD  
 

 
   
MARINE
 
A SMALL CRAFT ADVISORY IS IN EFFECT TONIGHT UNTIL WEDNESDAY  
NIGHT FOR THE GULF WATERS. A WEAK COLD FRONT IS CURRENTLY LOCATED  
OVER CENTRAL ALABAMA AS OF THIS MORNING. A LARGE HIGH OVER MIDDLE  
MISSISSIPPI VALLEY WILL BUILD BEHIND IT AND ELONGATE OVER THE OHIO  
VALLEY AND MID ATLANTIC BY THE MIDDLE OF NEXT WEEK. WE EXPECT THIS  
FEATURE TO BRING AN EPISODE OF STRONG EAST WINDS OFFSHORE INCREASING  
UP TO 20 KNOTS BY TONIGHT BECOMING EAST 20 TO 25 KNOTS BY TUESDAY  
NIGHT AND NEAR 25 KNOTS WEDNESDAY THROUGH WEDNESDAY EVENING. THE  
WINDS ARE EXPECTED TO DECREASE BY THE WEEKEND. INCREASING SIGNIFICANT  
WAVES...HIGHEST ONE THIRD BEING AS HIGH AS 10 FEET AT TIMES OFFSHORE  
THROUGH LATE THIS UPCOMING WEEK. A SMALL CRAFT ADVISORY IS IN EFFECT  
UNTIL WEDNESDAY NIGHT AND MAY NEED TO BE EXTENDED. 77/BD  
 

 
   
PRELIMINARY POINT TEMPS/POPS
 
 
MOBILE 88 60 85 65 84 / 30 05 00 05 10  
PENSACOLA 88 66 85 68 84 / 30 10 00 10 10  
DESTIN 87 70 84 70 84 / 30 20 05 10 10  
EVERGREEN 87 55 84 60 84 / 30 05 00 00 10  
WAYNESBORO 86 53 85 59 85 / 30 05 00 00 05  
CAMDEN 85 54 83 59 83 / 30 05 00 00 05  
CRESTVIEW 88 59 85 62 84 / 30 10 05 05 10  
 

 
   
MOB WATCHES/WARNINGS/ADVISORIES
 
 
AL...NONE.  
FL...NONE.  
MS...NONE.  
GM...SMALL CRAFT ADVISORY FROM 1 AM TUESDAY TO 7 PM WEDNESDAY FOR THE  
FOLLOWING ZONES: COASTAL WATERS FROM DESTIN TO PENSACOLA FL  
OUT 20 NM...COASTAL WATERS FROM PENSACOLA FL TO PASCAGOULA  
MS OUT 20 NM...WATERS FROM DESTIN TO PENSACOLA FL FROM 20  
TO 60 NM...WATERS FROM PENSACOLA FL TO PASCAGOULA MS FROM  
20 TO 60 NM...  
 

 
 

 
 
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