000 FXUS61 KPHI 130022 AFDPHI AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 822 PM EDT MON MAY 12 2008 .SYNOPSIS... AN INTENSE LOW PRESSURE SYSTEM WELL EAST OF THE DELMARVA PENINSULA WILL MOVE FARTHER OUT TO SEA TONIGHT AND BE WELL OFFSHORE BY TUESDAY MORNING. HIGH PRESSURE IS THEN EXPECTED TO BUILD IN FROM THE WEST LATER TUESDAY INTO EARLY THURSDAY. A COLD FRONT IS FORECAST TO CROSS OUR REGION THURSDAY. A WAVE OF LOW PRESSURE SHOULD THEN RIDE ALONG THE FRONTAL BOUNDARY AND PASS SOUTH OF THE REGION ON FRIDAY. WEAK HIGH PRESSURE WILL THEN BUILD OVER THE NORTHEAST ON SATURDAY. ANOTHER COLD FRONT FROM THE NORTHERN PLAINS SHOULD PASS THROUGH THE AREA AROUND SUNDAY. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... WINDS HAVE DIMINISHED ALONG OUR SOUTHERN COASTAL SECTIONS, SO HAVE CANCELLED THE WIND ADVISORY. DRIER AIR IS NOW SHOWING SIGNS OF MOVING IN FROM THE NORTH. WILL CONTINUE TO END THE RAIN FROM NORTH TO SOUTH OVERNIGHT. THIS WILL BE FOLLOWED BY PARTIAL CLEARING IN ALL BUT COASTAL SECTIONS. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/... IF THERE IS ANY CONSOLATION WITH THEIR SYSTEM, ITS THAT IT WILL BE HEADING OFFSHORE FASTER THAN SOME OF THE PREVIOUS MODEL PROJECTIONS AND TUESDAY'S WEATHER LOOKS BETTER WITH RESPECT TO WINDS AND LACK OF PRECIPITATION. CONVECTIVE TEMPS ARE NOT EXPECTED TO BE REACHED, BUT THERE MIGHT STILL BE SOME HIGH LEVEL MOISTURE AND CLOUDS ASSOCIATED WITH THE CLOSED LOW CIRCULATION. BY THE END OF THE DAY, THE FLOW ALOFT WILL BECOME ANTICYCLONIC AND SHOULD LESSEN EVEN THE HIGH LEVEL MOISTURE. FULL SUN MACROS ARE PRETTY CLOSE IN LINE WITH ALL THE MOS DATASETS AND WAS FOLLOWED. A QUIET TUESDAY NIGHT IS IN STORE WITH GENERALLY CLEAR SKIES EXPECTED UNDERNEATH THAT RIDGE. THE ONE CONCERN WE MIGHT HAVE TO REVISIT IS THE POSSIBILITY OF SOME PATCHY FROST IN OUR FAR NORTHERN ZONES. RIGHT NOW DEW POINTS ARE EXPECTED TO START HIGH (ABOVE FREEZING), WHICH WOULD FAVOR DEW VS FROST. RIDGE AXIS IS EXPECTED TO PASS E OF OUR CWA ON WEDNESDAY WHICH WOULD OPEN THE DOOR FOR SOME HIGH AND MID LEVEL MOISTURE TO ARRIVE WITH THE NEXT SYSTEM. FORECAST CONVECTIVE TEMPS STILL EXPECTED TO BE PRETTY HIGH, SO IT DOES LOOK LIKE THE DAY SHOULD BE MAINLY SUNNY. THE WRF-NMM IS ABOUT 2C COLDER THAN THE GFS WITH ITS FCST H8 TEMPS, ALTHOUGH ETA AND GFS MOS ARE PRETTY CLOSE. WE GENERALLY UNDERCUT GFS MOS MAYBE A DEGREE OR SO MOST PLACES. SYSTEM FOR WEDNESDAY NIGHT HAS AN ORGANIZED WAA SHOT OVER THE OHIO VALLEY, BUT THE SUPPORT WEAKENS AS THIS FEATURE MOVES ACROSS OUR CWA. SHRAS SHOULD FORM IN THE OHIO VALLEY AND THEN ITS A QUESTION AS TO WHETHER THEY CAN MAINTAIN THEMSELVES OVERNIGHT. THUS WE HAVE A WEST TO EAST POP GRADIENT ACROSS OUR CWA. CONFIDENCE ABOUT MIN TEMPS NOT HIGH BECAUSE OF THE UNCERTAINTY ABOUT THE ARRIVAL OF THE CLOUDINESS. && .LONG TERM /THURSDAY THROUGH MONDAY/... A COUPLE OF SYSTEMS WILL AFFECT OUR CWA THROUGH THE EXTENDED PERIOD. SO GIVEN THE CURRENT LONG WAVE PATTERN FAVORING TROFFING IN THE EASTERN CONUS ITS MORE OF A QUESTION OF WHEN THAN IF. THE LARGER SCALE PRECIPITATION EVENT IS POSSIBLE ON FRIDAY AS A WAVE OF LOW PRESSURE IS EXPECTED TO FORM ON THE COLD FRONT. RIGHT NOW HIGHER CHANCES ARE FAVORED SOUTH VS NORTH IN OUR CWA, ALTHOUGH THE TREND HAS BEEN NORTHWARD. THERE SHOULD BE A PRECIPITATION FREE PERIOD LATER FRIDAY INTO EARLY SATURDAY, DEPICTED BETTER IN THE GRIDS THAN THE ZONE WORDING, BEFORE THE NEXT COLD FRONT APPROACHES FOR SUNDAY. THE ONLY CONSOLATION ABOUT THE LATTER IS THIS LOOKS MORE THE TYPICAL SHOWERY TYPE PRECIPITATION EVENT VS WHAT MIGHT BE ANOTHER SOAKER FOR FRIDAY. IN CONVECTIVE TERMS, FORECAST STABILITY INDICES DO NOT FAVOR THUNDER BEING INCLUDED FOR NOW. && .AVIATION/00Z TUESDAY THROUGH SATURDAY/... PRECIPITATION IS MOVING TO THE SOUTH BUT A FEW HOURS OF LIGHT RAIN STILL OVER ILG- MIV AND ACY. SKIES SHOULD REMAIN VFR AND WINDS FROM THE NORTH OR NORTH NORTHEAST AT 10 TO 15 KT. SKIES CLEAR OUT FROM THE NORTH TO SOUTH BY MORNING AND IT IS GOING TO BE A NICE VFR DAY. OUTLOOK... A MORE NOTED IMPROVEMENT IS EXPECTED ON TUESDAY AS DRIER AIR MAKES MORE OF A PUSH INTO OUR AREA. HIGH PRESSURE WILL BUILD IN FOR WEDNESDAY, THEN ANOTHER COLD FRONT APPROACHES THURSDAY. A WEAK AREA OF HIGH PRESSURE THEN TRIES TO BUILD IN ON FRIDAY. && .MARINE... WILL BE TAKING DOWN THE STORM WARNINGS EARLIER THAN THE 11 PM TIME. GUSTS NOW UNDER 40 KTS AS THE LOW CONTINUE TO MOVES SOUTHEAST OF THE COASTAL WATERS. WINDS SHOULD CONTINUED TO DIMINISH OVERNIGHT AND TUE MORNING SO THE GALES SHOULD IN TURN BE REPLACED BY SCA AROUND 12Z/8AM TUE. SEAS ARE RUNNING SIGNIFICANTLY HIGHER THE FCST BY THE WAVE WATCH MODEL...SPECIFICALLY 20 FT AT BUOY 44009. SEAS SHOULD GRADUALLY SUBSIDE OVER THE NEXT COUPLE OF DAYS AS THE LOW PULLS AWAY FROM THE COAST...BUT STRONG WINDS AROUND THE LOW WILL CONTINUE TO GENERATE WAVES OFFSHORE. THE REST OF THE WEEK LOOKS RELATIVELY TRANQUIL WITH HIGH PRESSURE OVER THE FORECAST WATERS ON WEDNESDAY...A FAIRLY WEAK COLD FRONT ON THURSDAY AND MORE HIGH PRESSURE BY THE END OF THE WEEK. && .TIDES/COASTAL FLOODING... THE COASTAL FLOOD WARNING WILL BE LEFT AS IS TO COVER THIS HIGH TIDES TONIGHT INTO TOMORROW MORNING...THE LATTER BEING THE HIGHER OF THE TWO. WARNINGS CONTINUE FOR DELAWARE RIVER AND BAY, AND OCEAN FRONT. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...COASTAL FLOOD WARNING UNTIL 8 AM EDT TUESDAY FOR PAZ070-071. NJ...COASTAL FLOOD WARNING UNTIL 8 AM EDT TUESDAY FOR NJZ012>014- 016>027. DE...COASTAL FLOOD WARNING UNTIL 8 AM EDT TUESDAY FOR DEZ001>004. MD...NONE. MARINE...STORM WARNING UNTIL 11 PM EDT THIS EVENING FOR ANZ431-450>455. GALE WARNING UNTIL 8 AM EDT TUESDAY FOR ANZ431-450>455. GALE WARNING UNTIL 8 AM EDT TUESDAY FOR ANZ430. && $$ SYNOPSIS...RPW/GIGI NEAR TERM...RPW/GIGI SHORT TERM...GIGI LONG TERM...GIGI AVIATION...EBERWINE/AMC MARINE...EBERWINE/AMC TIDES/COASTAL FLOODING...EBERWINE/AMC