FXUS61 KBOX 232031 AFDBOX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TAUNTON MA 331 PM EST MON NOV 23 2009 .SYNOPSIS... LOW PRESSURE ALONG THE CAROLINA COAST WILL MOVE UP THE COAST TONIGHT AND PASS EAST OF NANTUCKET TUESDAY. WEAK HIGH PRESSURE WILL MOVE ACROSS NEW ENGLAND WEDNESDAY. A LARGE GALE WILL BE CENTERED NEAR THE NEW ENGLAND COAST FRIDAY THEN MOVE INTO THE MARITIMES THIS WEEKEND. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... ONE BATCH OF SHOWERS MOVED NORTH THIS AFTERNOON AND MOISTENED THE LOWER ATMOSPHERE...MOST OF THE ACTION TOOK PLACE IN CONNECTICUT WHERE ONE TO TWO TENTHS OF RAIN WAS MEASURED. THIS MOISTENING WILL CONTINUE THROUGH THE EVENING. RADAR SHOWS MORE RAIN MOVING NORTH TOWARD RI/EASTERN MASS AND A SECOND AREA MOVING UP THE COAST TOWARD CONNECTICUT. WE WILL USE A BLEND OF MOS POPS...HAND-ADJUSTED UP ABOUT 5 PERCENT. CATEGORICAL POPS IN THE SOUTH AND EAST...AND LIKELY POPS NORTHWEST. NORTHEAST WINDS PICK UP A LITTLE ESPECIALLY OVER THE CAPE AND ISLANDS AS COASTAL LOW PRESSURE APPROACHES...BUT SHOULD STAY BELOW ADVISORY LEVEL. TEMPS/DEWPOINTS ARE A BLEND OF MOS. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/... LOW PRESSURE PASSES WELL EAST OF NANTUCKET TUESDAY. THIS MOVES THE ISENTROPIC LIFT NORTH AND NORTHEAST OF OUR AREA...WITH LINGERING SHOWERS TUESDAY MORNING AND EARLY AFTERNOON AS THE SUPPORTING UPPER TROF MOVES ACROSS. THE GFS DRIES OUT THE SUB-850 MB LAYER FAST...BUT THE NAM HOLDS ONTO THIS MOISTURE THROUGH THE DAY...THE GLOBAL STARTS DRYING OUT THIS LAYER AFTER 18Z. WE HAVE AGREED WITH THE SLOW CLEARING MOSTLY LATE TUESDAY INTO TUESDAY NIGHT. STIFF GUSTY NORTHEAST WINDS ACROSS THE CAPE AND ISLANDS TUESDAY MORNING AND MIDDAY AS THE OFFSHORE LOW MAKES ITS CLOSEST APPROACH. GFS FORECASTS 950 MB WINDS AT 40-45 KNOTS 12Z TUESDAY WHILE THE NAM HAS 35 KNOTS AND MUCH LESS FAVORABLE THERMAL PROFILE TO BRING THE WIND TO THE SURFACE. WILL BRING CAPE/IDS WINDS UP TO AROUND 20 KNOTS BUT KEEP BELOW ADVISORY LEVEL. SKIES CLEAR TUESDAY NIGHT AS THE AIRMASS DRIES OUT. TEMPS TUESDAY AND TUESDAY NIGHT ARE A BLEND OF MOS. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... MODEL UNCERTAINTY WED-THU MORNING LEADS TO A BELOW AVG CONFIDENCE ON FCST DETAILS THIS PERIOD THEN HIGH CONFIDENCE FOR COMBINED GREAT LAKES COASTAL MERGER THU NIGHT OR FRI FOLLOWED BY HIGH CONFIDENCE ON A DEVELOPING BLUSTERY WEEKEND. WED-THU...MAINTAINED CONSIDERABLE CONTINUITY WITH THE 4PM SUNDAY KBOX FCST DUE TO THE VARIOUS MODEL OUTPUTS. PROBABLY DRY WED INTO EARLY THU BUT AM UNCERTAIN DUE THE RESULTANT SFC WX BEING DEPENDENT ON SUBTLE BL WIND DIRECTION/ASSOCIATED TERRAIN LIFT. THE 00Z GFS MOS WAS NOT HEAVILY WEIGHTED...DUE TO UNCERTAINTY REGARDING CLEARING AND THE OUTPUT OF THE NAM AND GGEM TEMP FIELDS. LATE THU INTO THE WKND...BLV MODEL CONSENSUS FAVORS SOME SORT OF LOW PRES MOVING TO NEW ENGLAND WITH A PERIOD OF SHOWERS. THUNDER IS POSSIBLE BUT DID NOT FCST IN THE GRIDS OR WRITE INTO THE HWO AS ITS DAY 5. FOR THE COAST THIS COULD BE EITHER OR BOTH A BRIEF ELY GALE FRI FOLLOWED BY A BLUSTERY WKND WITH POCKETS OF WLY GALE FORCE GUSTS. TEMPS WERE MODIFIED AT NIGHT...UPWARD DUE TO EXPECTED MIXING AND THE 00Z/23 GFS MOS. EROSION...CONSTANCY OF ONSHORE FLOW AND LARGE ELY OCEAN SWELLS OF 10 FEET TUE INTO WED AND POSSIBLY AGAIN FRI. WE CANT FCST THE EXTENT OF EROSION BUT IT COULD BE SIGNIFICANT. && .AVIATION /21Z MONDAY THROUGH SATURDAY/... TONIGHT...CIGS DETERIORATING TO IFR THIS EVENING MOST TERMINALS...THEN REMAINING IFR OVERNIGHT. AREAS OF IFR VSBYS IN RAIN AND FOG. TUESDAY...WEST OF THE CAPE AND ISLANDS...MVFR CIGS AND VSBYS /IN RAIN AND FOG/ IN THE MORNING. CIGS WILL BE SLOW TO IMPROVE DURING THE AFTERNOON. ON THE CAPE AND ISLANDS...IFR CONDITIONS LINGER DURING THE DAY. TUE NIGHT...SKY CONDITIONS IMPROVING TO VFR FROM W TO E OVER THE COURSE OF THE NIGHT. LOCAL IFR VSBYS IN PATCHY FOG. OUTLOOK /WEDNESDAY THROUGH FRIDAY/... WED THROUGH THU...CONSIDERABLE UNCERTAINTY. LOW CONFIDENCE. GENERALLY VFR INTERIOR THOUGH WITH A PERIOD OF IFR ST/FOG EARLY WED AND EARLY THU. ALONG THE COAST-ESP CAPE COD AND THE ISLANDS...GENERALLY MVFR OR IFR CIGS OUTLOOKED. LEFTOVER RAIN/DRIZZLE TUE NIGHT. THU NIGHT AND FRI...HIGH CONFIDENCE OF IFR CONDS IN RAIN WITH A PERIOD OF GUSTY E 25 TO 35 KT COAST...POSSIBLY SHIFTING TO W FRI AFTN ALONG WITH IMPROVING CONDS. && .MARINE... TONGIHT...CAROLINA LOW PRESSURE MOVES UP THE COAST. SURFACE PRESSURE GRADIENT INCREASES A LITTLE. MODELS SHOW 30-35 KNOTS /ECMWF AND NAM/ OR 40-45 KNOTS /GFS/ AT 950 MB...WITHIN RANGE OF BEING BROUGHT TO THE SURFACE IN A HEAVIER BURST OF RAIN. THIS SHOULD CARRY ENOUGH POTENTIAL FOR GALE FORCE WINDS...SO WE WILL ISSUE A GALE WARNING FOR OVERNIGHT AND TUESDAY FOR THE SOUTHEAST AND SOUTHERN OUTER WATERS AND NANTUCKET SOUND...THE AREAS CLOSEST TO THE TRACK OF THE OFFSHORE LOW. ALL OTHER ZONES SHOW POTENTIAL FOR 25 KNOT WINDS AND/OR 5 FOOT SEAS...SO SMALL CRAFT ADVISORIES FOR ALL OTHER WATERS. WINDS DIMINISH TUESDAY NIGHT BUT SEAS REMAIN ABOVE 5 FEET ON THEOUTER WATERS. THE SCA WILL BE EXTENDED THROUGHT TUESDAY NIGHT. OUTLOOK /WEDNESDAY THROUGH FRIDAY/... LEFTOVER HAZARDOUS SEAS SCA WED AND THU IN THE OUTER WATERS THEN ANOTHER GALE CONDITION POSSIBLE FRIDAY. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. NH...NONE. RI...NONE. MARINE...GALE WARNING FROM 10 PM THIS EVENING TO 10 AM EST TUESDAY FOR ANZ232-254>256. SMALL CRAFT ADVISORY UNTIL 5 AM EST WEDNESDAY FOR ANZ231- 233>235-237-250-251. SMALL CRAFT ADVISORY FROM 7 PM THIS EVENING TO 5 PM EST TUESDAY FOR ANZ230-236. && $$ SYNOPSIS...WTB NEAR TERM...WTB SHORT TERM...WTB LONG TERM...DRAG AVIATION...WTB/NMB MARINE...WTB/DRAG