FXUS61 KPHI 260935
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
435 AM EST SAT DEC 26 2009

.SYNOPSIS...
LOW PRESSURE, LOCATED OVER EASTERN NORTH CAROLINA EARLY THIS
MORNING, WILL DRIFT TO THE NORTH AND IT SHOULD PASS OVER OUR
REGION TONIGHT. A COLD FRONT FROM THE WEST IS FORECAST TO ARRIVE
ON SUNDAY NIGHT, WITH ANOTHER COLD FRONT FROM THE NORTHWEST
EXPECTED ON MONDAY NIGHT. HIGH PRESSURE IS ANTICIPATED TO BUILD IN
FROM THE WEST FOR TUESDAY INTO THURSDAY. LOW PRESSURE MAY DEVELOP
ALONG THE SOUTHEAST COAST LATE IN THE WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AT 4:00 AM, RAIN CONTINUED TO SPREAD UP FROM THE SOUTH AND INTO
OUR REGION. TEMPERATURES REMAINED NEAR OR SLIGHTLY BELOW THE
FREEZING MARK IN PARTS OF THE POCONO REGION AND IN PARTS OF
EXTREME NORTHERN NEW JERSEY. AS A RESULT, WE WILL MAINTAIN THE
FREEZING RAIN ADVISORY UNTIL 9:00 AM. IT APPEARS AS THOUGH
TEMPERATURES WILL RISE ABOVE FREEZING AS A LOW LEVEL SOUTHEASTERLY
JET LIFTS OVER OUR REGION DURING THE MORNING HOURS.

THERE WAS A FAIRLY WIDE TEMPERATURES RANGE IN OUR REGION EARLY
THIS MORNING. WHILE READINGS WERE IN THE LOWER AND MIDDLE 30S IN
THE NORTH, THEY WERE IN THE MIDDLE 50S IN SUSSEX COUNTY, DELAWARE.
EVEN AS ALL LOCATIONS SEE AN INCREASE IN TEMPERATURES TODAY, WE
SHOULD MAINTAIN A FAIRLY GOOD GRADIENT FROM NORTH TO SOUTH.

THE LOW LEVEL JET WAS PROVIDING A FAIRLY GOOD FEED OF MOISTURE UP
FROM THE BAHAMAS AND THE WATERS OFF THE SOUTHEAST COAST. THE AXIS
OF THE JET EXTENDED UP OVER SOUTHERN NEW JERSEY AND EASTERN
PENNSYLVANIA EARLY THIS MORNING. IT SHOULD DRIFT EASTWARD,
REACHING NORTHERN NEW JERSEY AND THE UPPER DELAWARE RIVER BASIN
AROUND MIDDAY, AND EASTERN NEW YORK AND WESTERN NEW ENGLAND THIS
EVENING.

THE MODERATE PRECIPITATION WILL BE ALONG AND TO THE EAST OF THE
LOW LEVEL JET AXIS. AS A RESULT, PRECIPITATION AMOUNTS TODAY
SHOULD BE LIGHTER ON THE DELMARVA THAN THEY WILL BE IN NEW JERSEY
AND IN EASTERN PENNSYLVANIA. THE CHANCE FOR RAIN SHOULD ALSO END
ON THE UPPER DELMARVA DURING THE COURSE OF THE AFTERNOON.

PLEASE REFER TO THE HYDROLOGY SECTION BELOW FOR DETAILS REGARDING
EXPECTED RAINFALL AMOUNTS AND ANY FLOOD POTENTIAL.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
THE LOW LEVEL JET AND THE ASSOCIATED PRECIPITATION SHOULD
CONTINUE TO LIFT TO OUR NORTHEAST TONIGHT, ALLOWING DRY AIR TO
BUILD UP FROM THE SOUTHWEST.

THE CENTER OF A BROAD AREA OF LOW PRESSURE IN THE UPPER
ATMOSPHERE IS EXPECTED TO MEANDER OVER THE WESTERN GREAT LAKES
TONIGHT AND SUNDAY BEFORE IT SCOOTS TO THE EAST AND BECOMES AN
OPEN WAVE. THE AXIS OF THE WAVE IS FORECAST TO PASS OVERHEAD ON
MONDAY. THERE MAY BE SOME SNOW AND RAIN SHOWERS FROM SUNDAY NIGHT
INTO MONDAY.

WHILE THE SHORT TERM PERIOD WILL BEGIN WITH SLIGHTLY ABOVE NORMAL
TEMPERATURES, THE TREND WILL BE DOWNWARD AND WE SHOULD BE SLIGHTLY
BELOW NORMAL BY MONDAY.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
A REINFORCING UPPER LEVEL SHORT WAVE IS ANTICIPATED TO DROP DOWN
FROM THE NORTHWEST ON MONDAY NIGHT, FOLLOWED BY A SHOT OF COLD
AIR.

HIGH PRESSURE AT THE SURFACE AND ALOFT IS FORECAST TO BUILD
ACROSS OUR REGION FROM WEST TO EAST IN THE TUESDAY THROUGH
THURSDAY TIME FRAME.

WE WILL CONTINUE TO KEEP AN EYE ON THE POTENTIAL FOR YET ANOTHER
COASTAL STORM LATE IN THE WEEK.

&&

.AVIATION /10Z SATURDAY THROUGH WEDNESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.

IFR CONDITIONS ARE EXPECTED ACROSS THE ENTIRE AREA TODAY WITH LOW
CIGS AND VSBYS ALONG WITH AN EXTENDED PERIOD OF RAIN AND FOG.
WINDS ARE EXPECTED OUT OF AN EASTERLY DIRECTION THROUGHOUT THE
DAY, AND BE A BIT GUSTY. AS A FRONTAL BOUNDARY AND AN AREA OF LOW
PRESSURE MOVE THROUGH THE AREA LATER THIS EVENING, CONDITIONS WILL
IMPROVE ACROSS THE AREA OVERNIGHT SATURDAY. CIGS AND VSBYS SHOULD
BECOME VFR AS THE RAIN AND FOG END OVERNIGHT SATURDAY INTO SUNDAY
MORNING, AND WINDS WILL SWITCH TO A WESTERLY DIRECTION AND SHOULD
DIMINISH.

OUTLOOK...
A WEAK DISTURBANCE MAY MOVE THROUGH THE AREA SUNDAY NIGHT WHICH
COULD LEAD TO SOME SNOW SHOWERS. A FRONTAL BOUNDARY MAY CROSS THE
AREA MONDAY NIGHT, BUT SHOULD NOT PRODUCE MUCH ON THE WAY OF
PRECIPITATION EXCEPT A FEW SCATTERED SNOW SHOWERS. CONDITIONS OVER
THE NEXT SEVERAL DAYS SHOULD BE MOSTLY VFR EXCEPT WHEN ANY SHOWER
ACTIVITY DOES OCCUR WHICH COULD LOWER CIGS AND VSBYS. WINDS MAY BE
GUSTY THE NEXT SEVERAL DAYS, ESPECIALLY MONDAY INTO TUESDAY.

&&

.MARINE...
CONDITIONS HAVE NOT GOTTEN TO GALE FORCE YET, BUT ARE EXPECTED TO
AS WE MOVE THROUGH THE MORNING HOURS AND THE PRESSURE GRADIENT
BETWEEN A LOW PRESSURE TO OUR SOUTH ALONG AN APPROACHING FRONTAL
BOUNDARY AND HIGH PRESSURE TO OUR NORTH TIGHTENS. THERE IS SOME
PRETTY STRONG WINDS ALOFT THAT MAY MIX DOWN TO THE SURFACE AS
WELL. AS THE FRONT AND LOW PRESSURE APPROACH THE AREA LATER DURING
THE DAY, WINDS SHOULD BEGIN TO DIMINISH BELOW GALE FORCE. HOWEVER,
WINDS, AND ESPECIALLY WAVES, WILL REMAIN WELL ABOVE SMALL CRAFT
ADVISORY CRITERIA. WAVES COULD REMAIN ABOVE SMALL CRAFT CRITERIA
EARLY INTO NEXT WEEK, AND WINDS COULD BECOME QUITE GUSTY LATE
MONDAY INTO TUESDAY AS A STRONG NORTHWEST FLOW DEVELOPS BEHIND A
FRONTAL BOUNDARY THAT IS EXPECTED TO PASS LATE MONDAY LEADING TO
MORE GALE WARNINGS. HIGH PRESSURE SHOULD BUILD IN WEDNESDAY,
FOLLOWED BY ANOTHER POSSIBLE COASTAL STORM LATER IN THE WEEK.

TIDES SHOULD NOT BE A PROBLEM TODAY. EVEN WITH 1.5 TO 2.0 FT 
DEPARTURES, WE SHOULD REMAIN BELOW MINOR FLOODING STAGES. THE ONLY 
SITE THAT MAY GET CLOSE IS REEDY POINT WHICH COULD REACH AROUND 7 FT 
AROUND SUNRISE THIS MORNING. 

&&

.HYDROLOGY...
THROUGH 4:00 AM, WE HAVE RECEIVED GENERALLY A QUARTER TO A HALF
INCH OF RAIN IN MUCH OF OUR FORECAST AREA. WE ARE NOT ANTICIPATING
MUCH MORE THAN ANOTHER HALF INCH. AS A RESULT, MOST LOCATIONS
SHOULD BE ABLE TO HANDLE THE COMBINED RAINFALL AND SNOW MELT.

EVEN THOUGH WE HAVE ALREADY ISSUED A FLOOD WARNING FOR THE CHRISTINA 
RIVER IN NEW CASTLE COUNTY, DELAWARE, A FLOOD WATCH DOES NOT SEEM 
NECESSARY AT THIS TIME. ANY RIVER OR STREAM FLOODING SHOULD BE 
ISOLATED. HOWEVER, WE MAY SEE A FAIR AMOUNT OF LOCALIZED POOR 
DRAINAGE AREA FLOODING TODAY AS STORM DRAINS REMAIN BLOCKED BY 
LINGERING SNOW.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...FREEZING RAIN ADVISORY UNTIL 9 AM EST THIS MORNING FOR PAZ054-
     055.
NJ...FREEZING RAIN ADVISORY UNTIL 9 AM EST THIS MORNING FOR NJZ001.
DE...NONE.
MD...NONE.
MARINE...GALE WARNING UNTIL 4 PM EST THIS AFTERNOON FOR ANZ450>452.
     GALE WARNING UNTIL NOON EST TODAY FOR ANZ430-431-453>455.

&&

$$

SYNOPSIS...IOVINO
NEAR TERM...IOVINO
SHORT TERM...IOVINO
LONG TERM...IOVINO
AVIATION...ROBERTSON
MARINE...ROBERTSON
HYDROLOGY...IOVINO