000 FXUS61 KGYX 232012 AFDGYX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAY ME 312 PM EST MON NOV 23 2009 .SYNOPSIS... LOW PRESSURE DEVELOPING OFF THE MID ATLANTIC COAST WILL PASS SOUTHEAST OF THE REGION TONIGHT AND TUESDAY. HIGH PRESSURE WILL BUILD DOWN FROM TUESDAY NIGHT. && .NEAR TERM /THROUGH TONIGHT/... THE INVERSION HAS HELD FIRM THIS AFTERNOON...AND THE INVERSION LOOKS AS THOUGH IT IS LOWERING ACROSS THE MOUNTAINS AS WELL. WOULD EXPECT THAT ALL ZONES WILL BECOME MOSTLY CLOUDY DUE TO THE MOISTURE UNDER THE INVERSION. STARTING TO SEE THE RAIN FILL IN ACROSS SOUTHEAST NEW ENGLAND THIS AFTERNOON. AT THIS POINT...MODELS ARE IN FAIRLY GOOD AGREEMENT WITH THE PASSAGE OF THE SURFACE LOW. BASED ON THIS...WILL CONTINUE TO MENTION THE BEST CHANCE OF RAIN ACROSS SOUTHEAST NEW HAMPSHIRE AND SOUTHERN MAINE...AS THE BEST LIFT STAYS CLOSE TO THE MID LEVEL SHORT WAVE LIFTING NORTHEAST WITH THE SURFACE LOW. IT APPEARS AS THOUGH THERE WILL BE A FAIRLY SHARP CUTOFF TO THE PRECIPITATION AS THE COLUMN JUST ABOVE THE INVERSION IS VERY DRY. FOR NOW...WILL KEEP THE MENTION OF PRECIPITATION OUT OF THE MOUNTAINS AND GRADUATE RAIN CHANCES TO THE COAST. THE COLUMN APPEARS TO BE TOO WARM TO SUPPORT ANYTHING OTHER THAN RAIN...EXCEPT FOR POSSIBLY THE MOUNTAINS. WOULD NOT EXPECT MUCH OF A CHANGE IN TEMPERATURE TONIGHT GIVEN LITTLE AIRMASS CHANGE...AND LOWS WERE BASED ON A MOS BLEND. && .SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/... THE SURFACE LOW MAKES IT CLOSEST APPROACH DURING TUESDAY MORNING. AGAIN...THE BEST RAIN CHANCES WILL BE KEPT NEAR THE COAST...AS THE BEST MID LEVEL LIFT PARALLELS THE COAST. ALL MODELS SHOW A WESTWARD EXPANSION OF THE PRECIPITATION THROUGH THE MID COAST AND EAST AS THE LOW EXITS. WILL ALLOW RAIN CHANCES TO LINGER THROUGH THE EVENING DUE TO THIS. THE 1200 UTC GFS IS THE MOST AGGRESSIVE WITH CLEARING BEHIND THE MID LEVEL SYSTEM TUESDAY AFTERNOON AND EVENING. THIS APPEARS TO BE OVERDONE...AS DRYING BEHIND THE LOW DOES NOT LOOK THAT STRONG. FOR THAT REASON...EVEN ACROSS THE CONNECTICUT RIVER VALLEY. WITH CLOUDS AND A NORTHEAST WIND...NOT EXPECT MUCH OF A TEMPERATURE RECOVERY TUESDAY...AND HIGHS WERE BASED ON A MOS BLEND...THEN DROP THEM A COUPLE OF DEGREES. THE FORECAST PROBLEM FOR TUESDAY NIGHT WILL BE CLEARING. AGAIN... THE 1200 UTC GFS IS THE MOST AGGRESSIVE WITH CLEARING...BRINGING MUCH DRIER AIR WITH HIGH PRESSURE DOWN FROM QUEBEC. NOT SURE THE MOISTURE WILL BE SO EASY TO REMOVE FROM UNDER THE INVERSION IN PLACE. THIS COULD TAKE UNTIL LATE NIGHT TO OCCUR. AS SUCH...THE 1200 UTC GFS MOS NUMBERS APPEARS TOO COLD...AND A BLEND WAS USED FOR LOWS. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... FOR WEDNESDAY MODELS ARE INDICATING A 500 RIDGE OVER THE AREA. SKIES WILL GENERALLY BE PARTLY TO MOSTLY SUNNY WITH ABOVE NORMAL TEMPERATURES. HIGHS WILL CLIMB INTO THE MID AND UPPER 50S IN THE SOUTH AND MID TO UPPER 40S IN THE MOUNTAINS. WED NIGHT THE 500 RIDGE MOVES EAST OF THE AREA ALLOWING CLOUDS TO INCREASE. THIS WILL KEEP LOW TEMPS UP AND EXPECT ONLY LOCATIONS TO DROP BELOW FREEZING WILL BE IN THE MOUNTAINS. FOR THURSDAY FLOW ALOFT COMES OUT OF THE SW AS 500 LOW DROPS INTO THE MIDWEST. EXPECT MORE CLOUDS THAN SUN HOWEVER I MAY BE A BIT PESSIMISTIC. HIGH TEMPS WILL ONCE AGAIN BE ABOVE NORMAL AND CLIMB INTO THE LOWER TO POSSIBLY MID 50S SOUTH AND MID TO UPPER 40S NORTH. THURSDAY NIGHT EXPECT CLOUDY CONDITIONS WITH LOW TEMPS REMAINING ABOVE FREEZING AT MOST LOCATIONS. FRIDAY THE FOECAST STARTS TO GET A BIT FUZZY. ALL MODELS ARE FORECASTING CYCLOGENESIS ALONG THE NORTHEAST COAST HOWEVER THE PLACEMENT AND TRACK ARE IN DOUBT. IT DOES LOOK LIKE A GALE CENTER WILL BE LOCATED SOMEWHERE NEAR THE NEW ENGLAND COAST BY LATE FRIDAY WITH HEAVY RAIN LIKELY. LATE FRIDAY NIGHT AND SATURDAY COLD AIR STARTS TO GET PULLED INTO THE SYSTEM WHICH WILL CHANGE PRECIP TO SNOW OR A MIX OF SNOW AND RAIN. SNOW ACCUMULATION IS CERTAINLY PSBL IN THE MOUNTAINS ON THE BACKSIDE OF THIS SYSTEM. && .AVIATION /19Z MONDAY THROUGH SATURDAY/... IN THE NEAR TERM /TONIGHT/...CEILINGS ARE STILL HOVERING NEAR 3000 FEET AT THE INVERSION HOLDS IN PLACE AND THE BREAKS OVER THE OCEAN HAVE BECOME LESS NUMEROUS. THE EXCEPTION HERE IS THE HIGHER TERRAIN... WHICH IS ABOVE THE INVERSION IN PLACE. THE SURFACE WAVE DEVELOPING OFF THE MID ATLANTIC COAST THIS AFTERNOON...AND AS IT MAKES ITS CLOSEST APPROACH...CEILINGS WILL STEADILY LOWER THROUGH MVFR TO IFR AFTER 0600 UTC FOR ALL TERMINALS (WITH KLEB GOING DOWN LAST). AT THIS POINT...NOT EXPECTING THE RAIN TO BE HEAVY ENOUGH TO OBSCURE VISIBILITY TO MVFR/IFR EXCEPT FOR PERHAPS KPSM. IN THE SHORT TERM /TUESDAY AND TUESDAY NIGHT/...THE SURFACE LOW MAKES IT CLOSEST APPROACH TUESDAY AFTERNOON. AHEAD OF THE LOW...THE NORTHEAST FLOW WILL TRAP MOISTURE UNDER THE LOWERING INVERSION...AND ALL TERMINALS SHOULD SEE IFR/LIFR CEILINGS THROUGH AT LEAST 1800 UTC (WITH THE LOWEST CEILINGS AT KPWM/KPSM). AFTER THE LOW PASSES TUESDAY EVENING...MODEL DIVERGE ON JUST HOW FAST THE MOISTURE UNDER THE INVERSION GETS MIXED OUT. SINCE THE PUSH OF DRY AIR BEHIND THE LOW SHOULD COME LATER AT NIGHT...WOULD EXPECT CONDITIONS TO SLOWLY IMPROVE TO MVFR THEN VFR BETWEEN 0300 UTC AND 0900 UTC WEDNESDAY. LONG TERM... EXPECT VFR FOR WED AND THURSDAY WITH CONDITIONS DETERIORATING TO IFR/LIFR FRIDAY. && .MARINE... IN THE NEAR TERM /TONIGHT/...WINDS AND SEAS ARE CLOSE TO SMALL CRAFT LEVELS THIS AFTERNOON...THE SMALL CRAFT ADVISORY WILL BE IN EFFECT WITH THE UPDATED FORECAST PACKAGE. NOT MUCH CHANGE IN FORECAST PHILOSOPHY FROM PREVIOUS PACKAGE. MODELS ARE IN GOOD AGREEMENT WITH THE PASSAGE OF THE SURFACE LOW LATE TONIGHT AND TUESDAY MORNING. AHEAD OF THE LOW...THE SURFACE GRADIENT TIGHTENS ENOUGH TO BRING SMALL CRAFT WINDS TO ALL WATERS. THERE IS A SMALL CHANCE OF NEAR GALE FORCE GUSTS AT IOSN3 BETWEEN 0600 UTC AND 1200 UTC TUESDAY...BUT NOT ENOUGH TO RAISE A GALE WARNING THERE. MODELS TEND TO UNDERFORECAST NORTHEAST WINDS IN THIS TYPE OF SITUATION...SO THAT ZONE WILL NEED TO BE WATCHED. SEAS ARE ALREADY STARTING TO RESPOND TO THE EAST TO NORTHEAST FETCH...AND ALL OCEAN WATERS SHOULD SEE SMALL CRAFT SEAS BEFORE 0300 UTC TUESDAY. SEAS SHOULD INCREASE IN THE BAYS AS WELL...BUT IT MAY TAKE UNTIL LATE TONIGHT OR TUESDAY MORNING BEFORE THIS HAPPENS. IN THE SHORT TERM /TUESDAY AND TUESDAY NIGHT/...THE SURFACE LOW MAKES IT CLOSEST PASS TUESDAY MORNING. AGAIN...ALL WATERS SHOULD BE EXPERIENCING SMALL CRAFT WINDS AS THE GRADIENT CERTAINLY SUPPORTS THIS. WILL INCLUDE 30 KNOT GUSTS FOR THE OCEAN WATERS AS WELL. THE NORTHEAST FETCH SHOULD BRING THE BAYS TO SMALL CRAFT SEAS...ESPECIALLY ON THE OUTER EDGES. THE SURFACE LOW PASSES LATE TUESDAY AFTERNOON AND TUESDAY EVENING. WHILE THE GRADIENT SLOWLY RELAXES...WINDS SHOULD DROP BELOW SMALL CRAFT LEVELS AFTER 0600 UTC WEDNESDAY. HOWEVER...THE SMALL CRAFT ADVISORY HAS BEEN EXTENDED AS SEAS SHOULD BE BE NEARLY FULLY DEVELOPED FOR THE FETCH...AND MAY TAKE INTO WEDNESDAY BEFORE DROPPING BELOW 5 FEET. LONG TERM... SEAS WILL BE SUBSIDING WED THEN QUITE ON THE WATERS UNTIL FRIDAY WHEN GALES ARE POSSIBLE WITH A DEVELOPING COASTAL LOW. GALE/SCA MAY LINGER INTO SUNDAY AS SYSTEM DEPARTS. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...NONE. NH...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 5 AM EST WEDNESDAY FOR ANZ150>154. && $$ LONG TERM...HAWLEY