FXUS64 KMOB 140542 AFDMOB AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MOBILE AL 1140 PM CST TUE DEC 13 2011 .AVIATION UPDATE (14/06Z ISSUANCE)...LOW CIG AND VSBY CONDITIONS CONTINUE. FOES IMAGER 11-3.9 AND MODIS POLAR ORBITER CONTINUE TO INDICATE A LOW STRATUS DECK WITH LOW VISIBILITY IN A LAYER WHOSE EDGE OVERLAYS A LINE FROM NEAR FOLEY TO BAY MINETTE AND ON UP TO CAMDEN. POINTS WEST OF SAID LINE ARE PRETTY WELL SOCKED IN AND PRETTY CLEAR ELSEWHERE. HAVE THEREFORE KEPT REDUCED PREVAILING GROUP TO A QUARTER MILE AND VV001 FOR BFM AND MOB. && .PREV DISCUSSION... /ISSUED 248 PM CST TUE DEC 13 2011/ SHORT TERM (TONIGHT THROUGH FRIDAY NIGHT)...A SHARP UPPER RIDGE AXIS LOCATED JUST WEST OF THE FORECAST AREA MOVES ACROSS THE AREA TONIGHT THEN INTO THE WESTERN ATLANTIC ON THURSDAY AS A STRONG SHORTWAVE SYSTEM EJECTS NORTHWARD ACROSS THE PLAINS AND INTO QUEBEC. A STRONG SURFACE HIGH OVER THE EAST CENTRAL STATES MOVES LITTLE THROUGH WEDNESDAY THEN ALSO MOVES OFF INTO THE ATLANTIC WEDNESDAY NIGHT INTO THURSDAY. THE SURFACE HIGH SETS UP AN EASTERLY FLOW OVER THE AREA TONIGHT THEN SOUTHEAST FOR WEDNESDAY INTO WEDNESDAY NIGHT. EXPECT TO SEE INCREASING AMOUNTS OF FOG DEVELOPMENT...ESPECIALLY BY WEDNESDAY NIGHT AS THE SOUTHEAST FLOW RETURNS GULF MOISTURE ACROSS COOL NEAR SHORE WATERS. WILL HAVE PATCHY FOG AREA WIDE TONIGHT THEN PATCHY DENSE FOG WEDNESDAY NIGHT...ALTHOUGH THIS MAY ULTIMATELY TURN OUT TO BE A DENSE FOG EVENT. A SURFACE LOW ASSOCIATED WITH THE PLAINS SYSTEM BRINGS A TRAILING COLD FRONT ACROSS THE SOUTHERN PLAINS WEDNESDAY NIGHT WHICH DECELERATES WHILE MOVING SLOWLY INTO THE REGION ON THURSDAY NIGHT. THE GFS/ECMWF AND GEM ARE IN FAIR AGREEMENT ON MOVING THE SLOW MOVING FRONT TO NEAR A LCH/JAN/HSV LINE BY 12Z FRIDAY THEN THROUGH THE FORECAST AREA BY NEAR 06Z SATURDAY. INSTABILITY REMAINS LIMITED MEANWHILE AND HAVE STAYED WITH SHOWERS AS THE PRECIP TYPE EXCEPT FOR SOME EMBEDDED STORMS ON FRIDAY. WILL CONTINUE WITH A DRY FORECAST THROUGH WEDNESDAY NIGHT THEN HAVE SMALL POPS OVER THE WESTERN PORTION OF THE AREA THURSDAY. POPS THURSDAY NIGHT WILL RANGE FROM GOOD CHANCE OVER THE NORTHWESTERN PORTION TO SLIGHT CHANCE OVER THE NORTHWEST FLORIDA PANHANDLE WITH SIMILAR POPS FRIDAY NIGHT. TEMPERATURES WILL BE RATHER MILD WEDNESDAY THROUGH FRIDAY WITH HIGHS WARMING TO THE LOWER TO MID SEVENTIES WITH OVERNIGHT LOWS IN THE LOWER FIFTIES INLAND TO UPPER FIFTIES CLOSER TO THE COAST. /29 LONG TERM (SATURDAY THROUGH TUESDAY)...A WELL DEFINED SHORTWAVE TROF MOVES ACROSS THE FORECAST AREA ON SATURDAY BUT DEEP LAYER DRY AIR FLOWING INTO THE REGION IN THE WAKE OF THE FRONT WILL JUST HAVE SMALL POPS FOR PATCHES OF LIGHT RAIN. A DRY FORECAST FOLLOWS FOR SATURDAY NIGHT THROUGH MONDAY AS RIDGING BUILDS INTO THE REGION WHILE A PREVIOUSLY CUT OFF LOW OVER THE SOUTHWEST STATES ADVANCES INTO THE SOUTHERN PLAINS. THIS NEXT SYSTEM EJECTS OFF TO THE NORTHEAST ACROSS THE PLAINS THROUGH TUESDAY WITH AN ASSOCIATED SURFACE LOW BRINGING A TRAILING COLD FRONT INTO THE REGION...AND THROUGH THE FORECAST AREA TUESDAY NIGHT. MOISTURE RETURN AHEAD OF THE FRONT IS LIMITED AND SUPPORTS JUST SMALL POPS FOR MONDAY NIGHT THROUGH TUESDAY. TEMPERATURES WILL HAVE RETURNED TO SEASONABLE LEVELS FOR SATURDAY THEN GRADUALLY MODERATES TO SEVERAL DEGREES ABOVE SEASONABLE LEVELS BY TUESDAY. /29 AVIATION (18Z ISSUANCE)..STUBBORN LIFR CIGS/LIFR TO IFR VISBYS ARE ERODING AT A PRETTY PREDICTABLE RATE...WITH THE BACK EDGE OF THE STRATUS DECK ERODING WESTWARD AT ABOUT 6-7KNOTS. HAVE ADJUSTED TIMING FOR THIS AFTERNOON USING THIS. TONIGHT...GUIDANCE IS HINTING AT ANOTHER FOG/STRATUS EVENT...AND WITH A SWITCH IN THE SFC WINDS TO SE WEDNESDAY...A PROLONGED EVENT IS POSSIBLE. WITH WATER TEMPS RANGING FROM AROUND 60 OFF THE MISS COAST TO UPPER 60S OFF THE WESTERN FL PANHANDLE...AND LOWER 70S DEGREE AIR MOVING OVER THIS WATER...THE BEST CHANCE WILL BE ALONG AND WEST OF THE AL/MS STATE LINE TONIGHT...AREA-WIDE WEDNESDAY NIGHT INTO THURSDAY. PERSISTENT IFR TO LIFR CIGS/VISBYS ARE LIKELY. /16 MARINE...SURFACE HIGH PRESSURE OVER THE APPALACHIANS WILL MEANDER EAST TO THE NJ TO NC ATLANTIC COAST TONIGHT INTO WEDNESDAY. THIS SURFACE HIGH WILL THEN GET SHOVED SOUTH AS A FRONT APPROACHES THE AREA...TO OVER THE WESTERN ATLANTIC WITH A RIDGELINE STRETCHING WEST OVER THE NORTHEASTERN GULF COAST BY FRIDAY. GUIDANCE IS CONSISTENT IN THE FRONT MOVING OFFSHORE FRIDAY NIGHT INTO SATURDAY...WITH MODERATE TO STRONG OFFSHORE FLOW FOLLOWING. /16 FIRE WEATHER...HIGH PRESSURE OVER THE EAST CENTRAL STATES MOVES INTO THE WESTERN ATLANTIC ON THURSDAY AS A COLD FRONT ADVANCES ACROSS THE SOUTHERN PLAINS. THE FRONT IS ANTICIPATED TO SLOWLY MOVE THROUGH THE AREA FRIDAY AFTERNOON INTO FRIDAY NIGHT. AFTERNOON RELATIVE HUMIDITIES REMAIN WELL ABOVE CRITICAL LEVELS THROUGH FRIDAY. PATCHY LATE NIGHT FOG IS EXPECTED EACH NIGHT THROUGH THURSDAY NIGHT. /29 && .PRELIMINARY POINT TEMPS/POPS... MOBILE 53 72 58 73 / 05 05 10 10 PENSACOLA 52 70 57 72 / 05 05 10 10 DESTIN 54 68 58 70 / 05 05 10 10 EVERGREEN 44 71 52 74 / 05 05 10 10 WAYNESBORO 46 71 55 75 / 05 05 10 20 CAMDEN 45 70 53 74 / 05 05 10 20 CRESTVIEW 45 73 50 75 / 05 05 10 10 && .MOB WATCHES/WARNINGS/ADVISORIES... AL...NONE. FL...NONE. MS...NONE. GM...NONE. && $$