FXUS61 KPHI 301904
AFDPHI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
204 PM EST MON NOV 30 2009
.SYNOPSIS...
A COLD FRONT WILL MOVE ACROSS THE REGION SLOWLY TODAY AND THEN
OFF THE COAST THIS EVENING. A RIDGE OF HIGH PRESSURE WILL BUILD
IN BEHIND THE FRONT TONIGHT AND SWING TO THE COAST ON WEDNESDAY
INTO WEDNESDAY NIGHT. OUR NEXT WEATHER-MAKER WILL BE COMING FROM
THE GULF COAST AS LOW PRESSURE DEVELOPS THERE WEDNESDAY AND THEN
MOVES NORTHEAST INTO OUR DIRECTION FOR WEDNESDAY NIGHT AND
THURSDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE FRONT HAS FINALLY MADE ITS WAY THROUGH PHILADELPHIA THIS
AFTERNOON AND WILL CONTINUE TO PUSH EASTWARD, MOVING OFF THE COAST
THIS EVENING.
RADAR IMAGERY SHOWS THE MAJORITY OF THE STEADIER PRECIPITATION TO
BE ALONG OR IN FRONT OF THE BOUNDARY WITH LIGHTER SHOWERS
ELSEWHERE. TEMPERATURES WERE DROPPING BEHIND THE FRONT ON DECENT
COLD AIR ADVECTION, AND WHERE RAIN WAS FALLING AHEAD OF THE FRONT
THE TEMPERATURE/DEW POINT SPREAD WAS SHRINKING STEADILY.
TEMPERATURES WERE ADJUSTED TO BETTER REFLECT THE CURRENT
OBSERVATIONS AND TRENDS. OTHERWISE, THE GENERAL TENOR OF THE
FORECAST REMAINS UNCHANGED.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
SURFACE RIDGE NOSES INTO PENNSYLVANIA AS THE FRONT DEPARTS THE
COAST. MINOR DISTURBANCE HANGS BACK OVER THE GREAT LAKES TONIGHT
THEN SWINGS ACROSS THE ADIRONDACKS TUESDAY WITH A FEW EARLY MORNING
SNOW SHOWERS EXTENDING DOWN TO OUR NORTHWESTERN ZONES IN THE POCONOS
OF PENNSYLVANIA. THE UPPER AND SURFACE RIDGE PUSH NORTH DURING
THE NIGHTTIME TUESDAY AND CLEAR THE WEATHER OUT ALTHOUGH
BRINGING SOME MUCH COOLER TEMPERATURES. WE'LL DROP INTO THE MID
20S TO MID 30S THE NEXT COUPLE OF NIGHTS AND NORMAL HIGHS OF UPPER
30S TO LOWER 50S FOR TUESDAY. UNDER FAIR SKIES FOR TUESDAY NIGHT
TEMPERATURES DROP AGAIN TO THE MID 20S TO MID 30S.
AT THIS JUNCTURE WE TURN OUR ATTENTION TO THE SOUTHWEST OR GULF
COAST AND AWAIT THE ARRIVAL OF A WINDY WET SYSTEM.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
THE SPLIT FLOW WILL PHASE DURING THIS PERIOD WITH THE NORTHERN
BRANCH DIVING SOUTH TO THE MID SECTION OF THE COUNTRY WHILE THE
SOUTHERN BRANCH WITH A CLOSED LOW OPENS UP INTO AN OPEN WAVE. THE
SURFACE REFLECTION'S CLOSED LOW IS DEEPENING AS IT MOVES NORTHEAST
INTO THE APPALACHIAN COUNTRY. EARLIER RUNS HAD THE LOW MOVING
CLOSE TO THE COAST AND THE CENTER PASSING OVER THE DELAWARE
VALLEY. HOWEVER...THE WESTERN ATLANTIC HIGH IS FAIRLY STRONG AND
IS FORCING THE LOW FARTHER INLAND. WE'RE IN FOR SOME HEAVY RAIN
GUSTY WINDS AND PERHAPS SOME DAMAGING WINDS IF THUNDERSTORMS
DEVELOP ALONG A NARROW BAND OF CONVECTION THAT IS TYPICAL WITH
THIS SET UP. THE WINDS AT 80H ARE 70 TO 80 KNOTS AND ANY
CONVECTION COULD BRING THESE WINDS DOWN TO THE SURFACE. THAT IS
ONE CAVEAT. THE OTHER IS THE TIGHTENING GRADIENT IS LIKELY TO
BRING NEAR GALE FORCE SOUTHERLY WINDS TO THE COAST AND WITH IT,
SOME RAPIDLY BUILDING SEAS. WHILE THE FLOW WILL BE PARALLEL SOUTH
TO NORTH THERE WILL BE SOME AREAS THAT EXPERIENCED SERIOUS BEACH
EROSION AND COULD SEE ABOUT A 12 -18 HOUR PERIOD OF POWER BREAKING
WAVES ON THE BEACH.
THE BUOY OFFSHORE IS FORECASTING 15 FEET BUT ITS THE WIND WAVE
DIRECTION THAT IS A LITTLE TROUBLING. WE GENERATE REALIZE ABOUT
HALF THE BUOY WAVE HEIGHTS ON THE BEACH OR IN THIS CASE 7 TO 8
FEET PROVIDING THE FOLLOWING FORECAST FROM THE WAVE WATCH DON'T GO
ANY HIGHER. IN ANY EVENT...I'LL BE ISSUING A NS FOR THE SHORE
POINTS TO ALERT THEM TO THE POSSIBILITY OF SOME HEAVY WAVE ACTION.
THIS IS NOT A NOR'EASTER BUT WILL STILL GENERATE STRONG WINDS AND
WAVES WITH THE HIGH PARKED TO THE EAST THIS TIME. THE PEAK TIME
FOR THE ACTION AT THIS TIME IS FROM LATE WEDNESDAY INTO MID
MORNING THURSDAY.
THE RAIN WILL MOVE IN DURING THE DAY WEDNESDAY AND RAPIDLY SPREAD
NORTHEAST WITH THE LOW. THE MAX QPF WILL RUN UP THE SPINE OF THE
APPALACHIANS LATE WEDNESDAY INTO WEDNESDAY NIGHT. WHILE MOST
MODELS KEEP THE LOW INLAND WITH THE GFS THE DEEPEST(983MB) MAX QPF
WILL BE OVER EASTERN PENNSYLVANIA AND ALONG THE COAST TO THE
CAROLINA'S. BY THURSDAY MORNING THE LOW IS INTO NORTHERN NEW YORK
WITH THE HEAVIEST PRECIPITATION MOVING JUST OFFSHORE AS THE WINDS
TURN AND THE COLD AIR ADVECTION STARTS CRANKING UP OVER THE GREAT
LAKES. WE MAY NEED WIND ADVISORIES AGAIN FOR THE ENTIRE AREA FOR
THURSDAY. AS THE LOW TRACKS WELL INTO EASTERN CANADA THE COLDEST
AIR REMAINS OVER TO OUR WEST. ANY ADDITIONAL SHOWERS WILL BE LIGHT
AND VERY COLD AIR IS LIKELY TO MAKE SURE THAT IT IS SNOW SHOWERS.
THE UPPER TROUGH WILL LIFT OUT TO THE NORTH ON SATURDAY AS HIGH
PRESSURE BUILDS OVER THE REGION FOR THE WEEKEND. WE'LL HAVE COLDER
THAN NORMAL NIGHTTIME TEMPERATURES WITH THE POCONOS DIPPING BELOW
20 INTO THE WEEKEND AND EVEN FREEZING TEMPERATURES ELSEWHERE.
&&
.AVIATION /19Z MONDAY THROUGH SATURDAY/...
THE FOLLOWING DISCUSSION IS FOR KOHL, KP NE, KT TN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
A LOW PRESSURE SYSTEM NR LK ONTARIO WILL MOVE ACRS NEW ENG TODAY AND
INTO THE CANADIAN MARITIMES TONIGHT. A COLD FRONT, EXTENDING
SOUTHWESTWARD FROM THIS LOW WILL CROSS THE AREA FROM W TO E THIS
AFTERNOON AND EVENING. SWLY WINDS AHEAD OF THE FRONT WILL INCREASE
DURG THE DAY AND COULD BECOME GUSTY, WITH GUSTS OF 20 TO 25 KT
POSSIBLE. CLOUDS WILL THICKEN AND LOWER AS MOISTURE INCREASES AND
RAIN WILL MOVE IN DURG THE MORNING HOURS FROM W TO E. CURRENT TAF
PKG MAY BE A BIT FAST WITH THE ONSET AND WILL LOOK CLOSER AT THAT
FOR FUTURE ISSUANCES. ONCE IT STARTS RAINING, EXPECT MVFR VSBYS
THEN CIGS AND SOME IFR CAN NOT BE RULED OUT, ESPECIALLY IF THE
PRECIP BECOMES HEAVY. PRECIP WILL END THIS EVENING ACRS THE AREA,
FROM W TO E AND A NW TO W WIND WILL CONTINUE THROUGH TONIGHT AND
INTO TUESDAY. OVERALL, NOT THE BEST DAY TO BE FLYING TODAY.
OUTLOOK...
HIGH PRESSURE WILL MOVE IN BEHIND THE DEPARTING COLD FRONT LATER
TONIGHT AND CONTINUE THROUGH WEDNESDAY AND EXPECT WINDS TO SUBSIDE
AS WELL. VFR CONDS WILL BE EXPECTED DURG THIS TIME. THEN, ALL EYES
TURN TO A STRONGER STORM WHICH IS EXPECTED TO DEVELOP ALONG THE
GLFMEX COAST ON TUESDAY AND THEN MOVE NEWD TWD THE MID-ATLC. PRECIP
IS FCST TO BREAK OUT FROM SW TO NE LATER WEDNESDAY INTO WEDNESDAY
NIGHT AND CONTINUE INTO THURSDAY. RAINFALL COULD BE HEAVY AT TIMES
AND A RUMBLE OF THUNDER CAN NOT BE RULED OUT, EVEN THOUGH ITS A BIT
EARLY TO HAVE ANY DECENT CONFIDENCE IN THAT. WINDS ARE EXPECTED TO
INCREASE MARKEDLY AND BECOME QUITE GUSTY DURING THIS TIME AND
CERTAINLY THERE WILL BE PERIODS OF SIGNIFICANT CIG AND VSBY
OBSTRUCTIONS. STAY TUNED. THIS STORM MOVES AWAY THURSDAY NIGHT WITH
A GUSTY NORTHWEST WIND IN ITS WAKE.
&&
.MARINE...
AN AREA OF LOW PRESSURE WILL MOVE TOWARD NEW ENG TODAY AND INTO SERN
CANADA TONIGHT. A CDFNT EXTENDING SWWD FROM THIS LOW WILL CROSS THE
AREA THIS AFTN AND EVENING. SWLY FLOW AHEAD OF THE FRONT WILL
INCREASE AND THEN WINDS WILL SHIFT TO THE NW AND W BEHIND THE FROPA.
WINDS WILL LIKELY STAY A BIT GUSTY BEHIND THE FRONT. PERIODS OF
RAIN ARE EXPECTED TODAY INTO EARLY TONIGHT. SCA FLAGS HAVE ALREADY
BEEN RAISED AND WILL NOT MAKE ANY CHANGES ATTM, BUT THEY MAY NEED TO
BE EXTENDED FURTHER INTO TUESDAY, BUT THAT POSSIBILITY DOES APPEAR
MARGINAL AT THIS TIME. SEAS SHOULD MAKE IT TO AROUND 5 FT.
HIGH PRESSURE THEN GRADUALLY BUILDS IN TUESDAY INTO WEDNESDAY.
MEANWHILE A STRONGER STORM IS EXPECTED TO DEVELOP ALONG THE GLFMEX
COAST ON TUESDAY AND MOVE NEWD TOWARD THE MID-ATLC ON WEDNESDAY.
THIS IS EXPECTED TO BE A MOISTURE-LADEN SYSTEM DUE TO ITS GULF
ORIGINS. RAIN WILL BEGIN LATER WEDNESDAY AND CONTINUE WELL INTO
THURSDAY. WINDS ARE EXPECTED TO INCREASE AS WELL AS SEAS AND THE
LATEST WAVEWATCH INDICATES 15 FT SEAS ARE POSSIBLE. WHILE WE DID
NOT GO THAT HIGH, HAVE TRENDED THEM UPWARD WITH THIS FCST. THERE IS
STILL SOME UNCERTAINTY WITH THE ULTIMATE TRACK OF THE LOW, BUT THE
MODEL CONSENSUS DOES KEEP THE LOW ALONG OR W OF THE APPALACHIANS
ATTM. NO MATTER HOW YOU SLICE IT, THERE COULD BE SOME COASTAL
IMPACTS. A MORE INLAND TRACK WOULD KEEP THE WINDS MORE SOUTH
AND SOUTHEAST, WHICH IS LESS DAMAGING TO OUR COASTAL LOCALES. A FULL
MOON OCCURS ON WEDNESDAY, THEREFORE THE ASTRONOMICAL TIDES WILL BE
ON THE HIGH SIDE, PERHAPS LEADING TO SOME COASTAL FLOODING CONCERNS.
WE WILL CONTINUE TO MONITOR THIS DEVELOPING SITUATION AND ALL MARINE
INTERESTS SHOULD TOO.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST TUESDAY FOR ANZ431-450>455.
&&
$$
SYNOPSIS...DELISI/EBERWINE
NEAR TERM...MEOLA/DELISI/EBERWINE
SHORT TERM...EBERWINE
LONG TERM...ROBERTSON
AVIATION...NIERENBERG
MARINE...NIERENBERG
