AFDGYX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAY ME 316 PM EDT FRI AUG 26 2011 .SYNOPSIS... WEAK HIGH PRESSURE ACROSS NORTHERN NEW ENGLAND TODAY WILL MOVE OFF TO THE EAST ON SATURDAY. HURRICANE IRENE WILL TRACK UP THE EAST COAST AND MAKE LANDFALL IN SOUTHERN NEW ENGLAND ON SUNDAY BEFORE TRACKING ACROSS NEW HAMPSHIRE AND MAINE SUNDAY NIGHT. HIGH PRESSURE BUILDS IN BEHIND THE HURRICANE WITH QUICKLY IMPROVING CONDITIONS ON MONDAY. && .NEAR TERM /THROUGH TONIGHT/... HIGH PRESSURE WILL SETTLE OVER MAINE AND NEW HAMPSHIRE TONIGHT. DIURNAL CU SHOULD DISSIPATE WITH TIME THIS EVENING. THIS WILL LEAVE US WITH CLEAR SKIES...LIGHT WINDS AND PATCHY FOG DEVELOPING. USED BLEND OF MET/MAV MOS FOR THE OVERNIGHT MINS. && .SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/... HIGH CLOUDS BEGIN TO STREAM NORTHWARD FROM IRENE. MODELS AND NHC/TPC ARE FORMING A TIGHTER CLUSTER FOR THE STORM TRACK...WITH THE EURO BEING THE FURTHEST WEST OVER NJ. CYCLONE PHASE DIAGRAMS CONTINUE TO SHOW THE STORM LEANING TOWARDS EXTRATROPICAL AS IT EXITS THE STATE OF MAINE. THERE COULD BE A `PRE" WHICH FORMS WELL OUT AHEAD OF THE SYSTEM. THIS MAY ENHANCE OUR RAINFALL IN A FEW AREAS. && .LONG TERM /SUNDAY THROUGH FRIDAY/... IRENE ACCELERATES AND MOVES ACROSS SOUTHERN SECTIONS OF ME/NH BY SUNDAY EVENING. SOME OPERATIONAL MODELS ARE BRINGING THE TIMING OF THE SYSTEM CROSSING OUR FORECAST AREA A LITTLE FASTER THAN OTHERS...ESPECIALLY THE GFS. HEAVY RAINFALL...ESPECIALLY OVER NEW HAMPSHIRE...VERY STRONG GUSTY WINDS AND HIGH STORM TIDES WILL ACCOMPANY THIS STORM. DETAILS ARE INCLUDED IN THE SECTIONS BELOW. OFFSHORE SYSTEM REMAINS RELATIVELY STATIONARY FOR LATE NEXT WEEK AND EARLY NEXT WEEKEND. MORE DETAILS LATER. && .AVIATION /19Z FRIDAY THROUGH WEDNESDAY/... SHORT TERM...AREAS OF IFR OVERNIGHT IN FOG. CONDITIONS BECOMING VFR AS THE FOG BREAKS SATURDAY MORNING. LONG TERM...CONDITIONS DETEORATE WITH IRENE ON SUNDAY. LIFR THROUGH SUNDAY EVENING...FOLLOWED BY CIGS/VSBY LIFTING. VFR THE REST OF THE WEEK. && .MARINE... SHORT TERM...NO FLAGS. LONG TERM...TROPICAL STORM CONDITIONS WITH POSSIBLY GUSTS TO HURRICANE FORCE OUT OVER THE COASTAL WATERS LATE SUNDAY AND THE FIRST HALF OF SUNDAY NIGHT. WINDS BECOMING WESTERLY AND GRADUALLY DIMINISHING LATE SUNDAY NIGHT AND EARLY MONDAY MORNING. NO FLAGS THEREAFTER...BUT OFFSHORE SYSTEM COULD BRING SWELLS TO THE REGION DURING PART OF NEXT WEEK. && .TROPICAL... AS OF EARLY AFTERNOON HURRICANE IRENE WAS STILL EXPECTED TO MOVE UP THE EAST COAST...MAKING LANDFALL IN SOUTHERN NEW ENGLAND ON SUNDAY. LATEST SATELLITE IMAGES OF THE STORM SHOW A WEAKENING TREND...THOUGH THIS MAY BE TEMPORARY. AS IT MOVES NORTHWARD IT WILL BE INTERACTING WITH THE COASTLINE FROM NORTH CAROLINA TO NEW JERSEY...LIKELY CONTRIBUTING TO A FURTHER WEAKENING TREND. IN ADDITION IT WILL BE UNDERGOING A TRANSITION TO AN EXTRA TROPICAL CYCLONE AS IT MOVES NORTH OF NORTH CAROLINA. BY THE TIME IT REACHES SOUTHERN NEW ENGLAND MODEL FORECASTS SHOW IRENE TO BE ASYMMETRICAL AND INCREASING IN FORWARD SPEED WITH DRY AIR INVADING THE CORE...MUCH LIKE A NOREASTER. WHAT THIS MEANS AS FAR AS IMPACTS IS THAT THE WIND FIELD WILL SPREAD OUT AND NO LONGER BE CONCENTRATED SYMMETRICALLY IN THE CENTER. WITH THE INCREASE IN FORWARD SPEED...THIS COULD ADD TO THE TOTAL WIND SPEED ON THE RIGHT SIDE OF THE TRACK OF THE CENTER... SO A LARGE AREA COULD EXPERIENCE STRONG WINDS FROM IRENE AS IT MOVES THROUGH... ESPECIALLY TO THE EAST OF THE TRACK. IN ADDITION...THE HEAVY RAIN THREAT WILL BE GREATEST TO THE NORTH AND WEST OF THE CENTER AND A THREAT FOR COASTAL FLOODING WILL EXIST ALONG THE COAST OF MAINE AND NEW HAMPSHIRE DUE TO A PROLONGED AND STRONG EASTERLY FLOW AND STORM SURGE. MORE DETAILS SEGMENTED BELOW: WINDS: WIND SPEEDS ARE STILL NOT CERTAIN AS ITS NOT CLEAR WHETHER IRENE WILL MAINTAIN ITS INTENSITY AS IT MOVES ALONG THE EAST COAST AND THROUGH SOUTHERN NEW ENGLAND. IN ADDITION...AS THE SYSTEM BECOMES COLD CORE THERE WILL BE A STABLE LAYER OF COOLER AIR AT THE SURFACE WITH NORTHEAST WINDS...KEEPING THE STRONG LOW LEVEL JETS ABOVE THE SURFACE. AT THIS TIME IT LOOKS LIKELY THAT 40 TO 60 MPH WINDS WILL BE WIDESPREAD ACROSS OUR AREA ON SUNDAY AND SUNDAY NIGHT. HIGHER WIND SPEEDS ARE POSSIBLE NEAR THE COASTLINE ESPECIALLY ACROSS COASTAL MAINE WHERE GUSTS TO 70 MPH ARE POSSIBLE. RAIN: VERY HEAVY RAINFALL RATES ARE EXPECTED WITH IRENE ESPECIALLY TO THE NORTH AND WEST OF THE CENTER. TOTAL RAINFALL AMOUNTS OF 3 TO 6 INCHES ARE EXPECTED ACROSS MUCH OF MAINE...WITH 4 TO 8 INCHES POSSIBLE OVER NEW HAMPSHIRE. THIS WILL BE FALLING IN THE PERIOD OF 18 TO 24 HOURS...SO IT COULD CAUSE SIGNIFICANT RISES ON RIVERS AND STREAMS AND CAUSE FLOODING IN URBAN AREAS WITH POOR DRAINAGE. A FLOOD WATCH HAS BEEN ISSUED TO DRAW ATTENTION TO THIS THREAT. STORM SURGE/TIDE: THE ASTRONOMICAL TIDE ON SUNDAY NIGHT IS PREDICTED AT 10.9 FEET AT PORTLAND AT 1111 PM. A PROLONGED EASTERLY FLOW WILL BE PILING UP A STORM SURGE OF OCEAN WATER INTO THE GULF OF MAINE AND UP TO THE COASTLINE. A STORM SURGE OF 1 TO 2 FEET IS EXPECTED...AND IF THIS OCCURS AT HIGH TIDE IT COULD CAUSE VULNERABLE LOW LYING AREAS ALONG THE IMMEDIATE COAST TO BE INUNDATED. IN ADDITION TO THE RISE IN WATER LEVEL...VERY ROUGH SEAS WITH WAVE HEIGHTS IN EXCESS OF 20 FEET WILL ACCOMPANY THE HIGH STORM TIDES. THOSE WITH INTERESTS ALONG THE IMMEDIATE COAST SHOULD BE PREPARED FOR POSSIBLE FLOODING. TORNADOES: AS WITH MOST LANDFALLING TROPICAL CYCLONES...THERE WILL BE A THREAT FOR TORNADOES IN PRECEDING RAIN BANDS ESPECIALLY TO THE EAST OF THE CENTER. THIS THREAT WILL BE GREATEST ON SUNDAY. ALTHOUGH THE LIKELIHOOD FOR TORNADOES IS LOW...IT CANNOT BE DISCOUNTED WITH A LANDFALLING TROPICAL CYCLONE AND WILL NEED TO BE MONITORED. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...FLOOD WATCH FROM SUNDAY MORNING THROUGH LATE SUNDAY NIGHT FOR MEZ007>009-012>014-018>028. NH...FLOOD WATCH FROM SUNDAY MORNING THROUGH LATE SUNDAY NIGHT FOR NHZ001>010-013-014. MARINE...NONE. && $$