NWS Area Forecast Discussion
000 FXUS64 KMOB 051406 AAA AFDMOB AREA FORECAST DISCUSSION...UPDATE... NATIONAL WEATHER SERVICE MOBILE AL 800 AM CST SUN FEB 5 2012 .MARINE...WINDS HAVE INCREASED TO 15 KNOTS NEAR THE COAST AND WILL BUILD OFFSHORE LATER THIS MORNING AND THIS AFTERNOON. DENSE FOG CONTINUES TO LIFT AS THE NORTHERLY FLOW CONTINUES TO BECOME BETTER DEVELOPED. STILL EXPECT 15 TO 20 WINDS AND BUILDING SEAS OVERNIGHT AS A BETTER SURGE OF COLDER AIR MOVES SOUTH OVER THE NORTH CENTRAL GULF. 32/EE && .UPDATE...HAVE ALLOWED FOR DENSE FOG ADVISORY TO EXPIRE AT 6 AM. MOSTLY PATCHY DENSE FOG STILL IS PRESENT GENERALLY SOUTH OF A LINE FROM CRESTVIEW TO GULF SHORES BUT THIS WILL IMPROVE AS THE FRONT CONTINUES EASTWARD EARLY THIS MORNING. /29 *** PREVIOUS DISCUSSION *** .SHORT TERM (TODAY AND TONIGHT)...DENSE FOG HAS BEGUN TO LIFT FROM WEST TO EAST THIS MORNING. AS A RESULT HAVE TRIMMED THE DENSE FOG ADVISORY WITH MAINLY PARTS OF SOUTHWEST ALABAMA AND NORTHWEST FLORIDA REMAINING IN THE ADVISORY UNTIL 6 AM THIS MORNING. THE DENSE FOG ADVISORY FOR THE REMAINING AREAS WILL LIKELY BE ALLOWED TO EXPIRE BY 6 AM. A MODERATE TO STRONG COLD FRONT MOVING ACROSS WESTERN SECTIONS OF THE CWFA THIS MORNING WILL MOVE EAST OF THE CWFA LATER THIS MORNING. LATEST MODEL SOUNDINGS DEPICT THE COLDER AIR MOSTLY IN THE LOWER LEVELS OF THE ATMOSPHERE GENERALLY UP TO ABOUT 5K FT. ALOFT HUMIDITY LEVELS REMAIN HIGH THROUGH TONIGHT RESULTING IN MOSTLY CLOUDY SKIES FOR THE CWFA TODAY AND TONIGHT. AREAS OF LIGHT RAIN MOSTLY OVER EASTERN SECTIONS OF THE CWFA THIS MORNING WILL MOVE OFF TO THE EAST LATER THIS MORNING. AS FOR TEMPS WILL LEAN CLOSE OR GO SLIGHTLY BELOW THE CURRENT 00Z MAV GUIDANCE THROUGH TONIGHT. 32/EE FOR MONDAY THROUGH TUESDAY NIGHT...A SHORTWAVE SYSTEM OVER THE OHIO RIVER VALLEY 12Z MONDAY MOVES OFF INTO THE ATLANTIC BY TUESDAY MORNING WITH ANOTHER SHORTWAVE SYSTEM MEANWHILE ADVANCING ACROSS THE PLAINS AND PHASING WITH A NEAR LONGWAVE TROF ADVANCING SOUTHWARD OUT OF CANADA AND INTO THE NORTHEASTERN STATES BY TUESDAY NIGHT. THIS PATTERN LEAVES A DEEP LAYER MOSTLY WESTERLY FLOW OVER THE SOUTHEAST STATES WITH FIRST A STRONG SURFACE HIGH OVER THE SOUTHERN PLAINS BUILDING INTO THE SOUTHEAST STATES AND REINFORCED BY A YET STRONGER AND LARGER SURFACE HIGH WHICH BUILDS INTO THE PLAINS THROUGH 12Z WEDNESDAY. DEEP LAYER MOISTURE GRADUALLY DECREASES OVER THE FORECAST AREA THROUGH THE PERIOD. THERE REMAINS A SMALL POTENTIAL FOR A FEW PATCHES OF LIGHT RAIN MONDAY THROUGH TUESDAY NIGHT AS A SERIES OF WEAK TO MODERATE SOUTHERN STREAM SHORTWAVES MOVE ACROSS THE FORECAST AREA...WITH A MUCH STRONGER SHORTWAVE ADVANCING INTO NORTHERN MISSISSIPPI LATE TUESDAY NIGHT ASSOCIATED WITH THE SYSTEM MOVING ACROSS THE NORTHEAST STATES. ISENTROPIC ANALYSIS SHOWS THAT NET LIFTING SHOULD REMAIN TOO WEAK AND THE OVERALL DRYING TREND OF THE ATMOSPHERE BOTH SUPPORT KEEPING MENTION OF PRECIP OUT OF THE FORECAST AT THIS TIME THROUGH TUESDAY NIGHT. SREF POPS ARE VERY LOW AS WELL THROUGH THE PERIOD. TEMPERATURES WILL BE SLIGHTLY ABOVE SEASONABLE LEVELS. /29 .LONG TERM (WEDNESDAY THROUGH SATURDAY)...THE SHORTWAVE TROF MOVES ACROSS THE NORTHEASTERN STATES THROUGH THURSDAY WHILE A CUT OFF UPPER LOW SLOWLY ADVANCES ACROSS THE BAJA AREA. THE GFS CONTINUES TO DEVELOP A SURFACE LOW OVER THE SOUTHWESTERN GULF WHICH TREKS NORTHEASTWARD TO THE NORTHEAST GULF ON THURSDAY THEN INTO THE WESTERN ATLANTIC THURSDAY NIGHT. THE GEM GENERALLY SUPPORTS THIS SOLUTION WITH SOME SUPPORT FROM THE ECMWF AS WELL WITH A SURFACE HIGH OTHERWISE CONTINUING TO BUILD FROM THE PLAINS INTO THE EASTERN STATES. HAVE STAYED CLOSE TO THE CURRENT PACKAGE WITH A RETURN OF SMALL POPS TO THE SOUTHERN PORTION OF THE FORECAST AREA WEDNESDAY NIGHT AND WENT WITH SLIGHT CHANCE POPS FOR MOST OF THE AREA ON THURSDAY AND BASED ON AVAILABLE GUIDANCE HAVE OPTED FOR A DRY FORECAST THURSDAY NIGHT. THE GFS ABSORBS THE CUT OFF LOW INTO A DEEP LONG WAVE TROF OVER THE EASTERN HALF OF THE CONUS FRIDAY INTO SATURDAY WHILE THE ECMWF WEAKENS THE CUT OFF LOW INTO AN OPEN WAVE WITH A MUCH WEAKER TROF PATTERN OVER THE EASTERN STATES BY EARLY THIS WEEKEND. THE CANADIAN GEM SOLUTION IS A BIT OF A COMPROMISE BUT CLOSER TO THE GFS AND HAVE USED A BLEND OF THE GEM/GFS FOR THE REMAINDER OF THE FORECAST. ANOTHER REINFORCING DOME OF HIGH PRESSURE BUILDS INTO THE PLAINS FRIDAY AND MORE SO INTO THE SOUTHEAST STATES SATURDAY PORTENDING A TREND TOWARD COOLER TEMPERATURES. THE OPERATIONAL GFS MAKES THIS TREND MUCH COLDER AND HAVE OPTED FOR TRENDING TOWARDS GFS ENSEMBLE AVERAGE TEMPERATURES BY SATURDAY CONSIDERING THE OVERALL UNCERTAINTY. MAY SEE SOME ISOLATED PATCHES OF LIGHT RAIN DUE TO A SERIES OF SHORTWAVES EJECTED FROM THE WEAKENING UPSTREAM CUT OFF LOW AND HAVE STAYED WITH SLIGHT CHANCE POPS FOR FRIDAY AND FRIDAY NIGHT OVER THE SOUTHERN PORTION OF THE FORECAST AREA...THEN DRY FOR SATURDAY AS PROGRESSIVELY DRIER DEEP LAYER AIR WORKS INTO THE AREA. /29 && .FIRE WEATHER...NO CONCERNS THROUGH TUESDAY AS AFTERNOON RELATIVE HUMIDITIES REMAIN ABOVE CRITICAL LEVELS BUT AFTERNOON RELATIVE HUMIDITIES LOOK TO DROP TO AROUND 30 PERCENT FOR MUCH OF THE AREA ON WEDNESDAY. THIS MAY SATISFY DURATION CRITERIA FOR THE NORTHWEST FLORIDA PANHANDLE ON WEDNESDAY BUT ERC VALUES ARE FORECAST TO REMAIN WELL BELOW 35 AND WINDS WILL BE RELATIVELY LIGHT. /29 && .AVIATION...LIFR TO IFR CONDITIONS THROUGH 15Z TODAY FOLLOWED BY VFR CONDITIONS THROUGH 12Z MON. CEILINGS WILL RANGE FROM 200 TO 1.5K FT THROUGH 15Z TODAY...FOLLOWED BY BKN TO OVC CONDITIONS AT AROUND 20KFT THROUGH 12Z MON. WINDS WILL BE NORTH AT 5 TO 10 KNOTS EARLY TODAY INCREASING TO 8 TO 12 KNOTS THROUGH 12Z MON. 32/EE && .MARINE...NORTHERLY WINDS AND SEAS WILL BUILD LATER TODAY AND TONIGHT IN RESPONSE TO A COLD FRONT MOVING SOUTHWARD OVER THE NORTH CENTRAL GULF. AREAS OF DENSE FOG MOSTLY NEAR THE COAST AND OVER INLAND BAYS AND SOUNDS CAN BE EXPECTED AHEAD OF THE FRONT MAINLY EARLY THIS MORNING. A LIGHT NORTHERLY WIND FLOW WILL PERSIST OVER THE MARINE AREA THROUGH MIDWEEK AS HIGH PRESSURE SETTLES OVER THE SOUTHEAST STATES WELL NORTH OF THE COAST. NORTHERLY WINDS AND SEAS WILL BUILD LATER IN THE WEEK IN RESPONSE TO A DEVELOPING AREA OF LOW PRESSURE TRACKING EASTWARD OVER THE NORTHERN AND CENTRAL GULF. 32/EE && .PRELIMINARY POINT TEMPS/POPS... MOBILE 71 47 65 43 / 20 05 10 10 PENSACOLA 72 49 64 46 / 20 05 10 10 DESTIN 72 51 65 48 / 20 10 10 10 EVERGREEN 70 46 65 40 / 20 05 10 10 WAYNESBORO 67 43 63 40 / 10 05 10 10 CAMDEN 66 45 63 39 / 20 05 10 10 CRESTVIEW 76 48 68 41 / 20 05 10 10 && .MOB WATCHES/WARNINGS/ADVISORIES... AL...NONE. FL...NONE. MS...NONE. GM...NONE. && $$
NWS MOB Office Area Forecast Discussion