000 FXUS61 KPHI 130516 AFDPHI AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 1216 AM EST FRI FEB 13 2009 .SYNOPSIS... INTENSE LOW PRESSURE OFF THE COAST OF MAINE THIS EVENING WILL CONTINUE TO MOVE NORTHEAST OVERNIGHT. THE STRONG GUSTY WINDS ARE EXPECTED TO DIMINISH OVERNIGHT. HIGH PRESSURE TO THE NORTH WILL GENERALLY INFLUENCE THE WEATHER FRIDAY AND OVER THE WEEKEND, BUT A WEAK STORM WILL PASS WELL TO THE SOUTH SATURDAY AND EARLY SUNDAY. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... STRONG AND GUSTY WINDS WERE CONTINUING TO DIMINISH AROUND MIDNIGHT. THERE WERE A COUPLE OF GUSTS IN THE MID 30 KNOT RANGE, AND ONE HIGHER OUTLIER, OTHERWISE GUSTS WERE IN THE PROCESS OF DIMINISHING AND THE WIND ADVISORY WAS CANCELLED / ALLOWED TO EXPIRE. SKIES HAVE CLEARED IN THE SOUTH, BUT REMAIN CLOUDY NORTH, WITH VARIABLE AMOUNTS IN BETWEEN. CLOUDS COULD LINGER OVER THE SOUTHERN POCONOS MUCH OF THE NIGHT. A SMALL CHANCE OF RAIN AND/OR SNOW SHOWERS WILL BE IN THE FORECAST THERE ALSO. && .SHORT TERM /6 AM THIS MORNING THROUGH SUNDAY/... HIGH PRESSURE WILL RIDGE ACROSS THE AREA FRIDAY AND THIS SHOULD SPELL A DRY FORECAST FOR OUR AREA. A WEAK/DRY COLD FRONT WILL CROSS THE AREA DURING THE LATE MORNING AND THIS MAY HAVE SOME CLOUDINESS WITH IT, SO THE DAYTIME FORECAST OF PARTLY CLOUDY SHOULD SUFFICE. IT WILL BE WINDY ON FRIDAY TOO, BUT NOT TO THE EXTENT LIKE WAS EXPERIENCED TODAY. WIND GUSTS OF 25 TO 30 MPH CAN BE EXPECTED, MAINLY DURING THE FIRST PART OF THE DAY. HIGH TEMPERATURES WILL BE ABOUT 10 DEGREES LOWER THAN TODAY WITH UPPER 30S AND LOW 40S UP NORTH AND MID TO UPPER 40S ACROSS THE PHILADELPHIA METRO AND DELMARVA AREAS. CONTINUED FAIR WEATHER AND COOL TEMPERATURES EXPECTED FRIDAY NIGHT WITH MAINLY CLEAR SKIES. A LOW PRESSURE SYSTEM IS SHOWN MY THE OPERATIONAL MODELS AS MOVING FROM THE LOWER OHIO VALLEY FRI NIGHT TO THE VA/NC COAST BY SAT NIGHT. THIS SYSTEM CONTINUES TO BE SUPPRESSED SOUTHWARD BY THE MODELS AND ANY CHANCES OF PRECIPITATION THAT WERE IN THE GRIDS PREVIOUSLY WERE REMOVED WITH MY FORECAST. I HAVE CONTINUED TO INDICATE MOSTLY CLOUDY OR CLOUDY SKIES FROM SATURDAY AFTERNOON INTO SATURDAY NIGHT. THE WRF FROM 12Z WAS THE CLOSEST TO BRINGING ANY PRECIPITATION TO OUR AREA, BUT THE HPC GENERALLY DID NOT USE IT IN THEIR FORECASTS. && .LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/... THE WEATHER FOR MUCH OF THE EXTENDED PERIOD LOOKS FAIRLY BENIGN. A STORM MAY AFFECT THE AREA TOWARD THE MIDDLE OR END OF NEXT WEEK. A ZONAL FLOW ACROSS THE EAST AT THE BEGINNING OF THE PERIOD WILL BRING A HIGH PRESSURE SYSTEM FROM THE NORTHERN PLAINS STATES ON SUNDAY TO THE MIDDLE ATLANTIC BY TUESDAY. THE HIGH WILL MOVE OFF THE EAST COAST WEDNESDAY MORNING. THIS SHOULD BRING A PERIOD OF DRY WEATHER WITH SEASONABLE TEMPERATURES. LOWS GENERALLY IN THE 20S WITH HIGHS IN THE UPPER 30S OR LOW 40S. DURING THIS PERIOD A LOW PRESSURE SYSTEM WILL BE MOVING SOUTH OF OUR AREA. THE TREND WITH THE MODELS HAS BEEN TO SUPPRESS ANY PRECIPITATION TO THE SOUTH AND KEEP IT OVER THE VA/NC AREA. DURING THE MIDDLE OF NEXT WEEK, THE UPPER PATTERN AMPLIFIES AND BECOMES PROGRESSIVE. A RIDGE OVER THE AREA TUE EVENING MOVES EAST AND IS GIVING WAY TO AN ADVANCING TROUGH. A SFC LOW IS INDICATED BY THE 00Z ECMWF AS FORMING OVER THE OHIO VALLEY WED AND MOVING TO OUR FORECAST AREA BY 12Z THU. AS AN UPPER LOW DEVELOPS ACROSS THE AREA, THE SFC LOW SLOWS JUST TO THE EAST. COULD BE AN INTERESTING PERIOD. WE HAVE CHANCE POPS IN THE GRIDS FOR THIS EVENT PRESENTLY, IN LINE WITH HPC PRODUCTS. && .AVIATION /05Z FRIDAY THROUGH TUESDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. THE JUST ISSUED TAFS MAINTAIN A VFR FORECAST THROUGHOUT. THE MAIN STORY REMAINS THE WIND. STRONG WINDS ARE FORECAST TO CONTINUE OFF THE GROUND OVERNIGHT. WHILE SOME DECOUPLING SHOULD OCCUR OVERNIGHT WE DID NOT FEEL CONFIDENT ENOUGH TO DROP THE WIND GUSTS IN ANY FORECAST PERIOD. WE INCREASED THE GUSTINESS AGAIN ON FRIDAY MORNING WHEN THERE SHOULD BE MORE MIXING. WINDS SHOULD THEN START GRADUALLY DECREASING AS THE AFTERNOON CONTINUES AND BY FRIDAY EVENING (AS DEPICTED IN THE KPHL TAF) BE GONE. AS FAR AS THE STRATOCUMULUS DECK GOES, ALL THE FORECAST MODELS INCREASE THE MOISTURE FROM NORTH TO SOUTH AS THE NIGHT CONTINUES. THIS DOES NOT ALWAYS TRANSLATE INTO CLOUDS, BUT FOR NOW WE DID FOLLOW THEIR LEAD. WHILE THE MOST STRATOCUMULUS SHOULD BE AT KRDG AND KABE, WE DID BRING IN A STRATOCUMULUS VFR CIG TO ALL THE TERMINALS TOWARD FRIDAY MORNING. THEN AS FORECAST MOISTURE BECOMES SCANTIER, WE ARE NOT FORECASTING A CIG AT ANY OF THE TERMINALS FROM LATE FRIDAY MORNING ONWARD. OUTLOOK... HIGH PRESSURE IS EXPECTED TO BUILD IN FROM THE WEST, WITH MAINLY VFR CONDITIONS ANTICIPATED FOR SATURDAY, SUNDAY, MONDAY AND TUESDAY. && .MARINE... STRONG LOW PRESSURE WILL PASS ACROSS CANADA'S ATLANTIC PROVINCES FROM TONIGHT INTO FRIDAY BEFORE MOVING OUT OVER THE NORTH ATLANTIC. THE CIRCULATION AROUND THE LOW WILL MAINTAIN STRONG WEST TO NORTHWEST WINDS OVER OUR REGION INTO FRIDAY. THE STRONGEST WINDS OVER OUR MARINE AREA WILL OCCUR TONIGHT AS THE AIR TEMPERATURES BEGINS TO DECREASE TO NEAR AND BELOW THE TEMPERATURE OF THE WATER. HIGH PRESSURE IS FORECAST TO BUILD IN FROM THE WEST FOR THE COMING WEEKEND AND FOR THE EARLY PART OF THE NEW WEEK. WIND SPEEDS ARE FORECAST TO REMAIN BELOW 25 KNOTS THROUGH THE PERIOD. && .TIDES/COASTAL FLOODING... THE STRONG OFFSHORE WINDS WILL LIKELY RESULT IN BLOWOUT TIDES. WHILE THERE MAY BE SOME LOW WATER ISSUES AROUND THE TIMES OF LOW TIDE THIS EVENING, MORE WIDESPREAD LOW WATER PROBLEMS ARE ANTICIPATED AROUND FRIDAY MORNING'S LOW TIDE. IT IS POSSIBLE THAT THE LOW WATER ADVISORY MAY EVENTUALLY NEED TO BE EXTENDED INTO FRIDAY EVENING FOR DELAWARE BAY AND FOR THE TIDAL DELAWARE RIVER, AS IT MAY TAKE WATER LEVELS A LITTLE LONGER TO RECOVER THERE. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...LOW WATER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR ANZ430- 431-450>455. GALE WARNING UNTIL 10 AM EST THIS MORNING FOR ANZ450>455. GALE WARNING UNTIL 6 AM EST EARLY THIS MORNING FOR ANZ430-431. && $$ SYNOPSIS...O'HARA / GIGI / RPW NEAR TERM.../ RPW / O'HARA SHORT TERM...O'HARA LONG TERM...O'HARA AVIATION...GIGI /IOVINO MARINE...IOVINO TIDES/COASTAL FLOODING...IOVINO