Area Forecast Discussion
Issued by NWS Mt. Holly, NJ

Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS61 KPHI 230856
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
356 AM EST TUE DEC 23 2014

.SYNOPSIS...
A WEAK AREA OF LOW PRESSURE WILL CONTINUE TO LIFT NORTHWARD ALONG
THE COAST EAST OF THE AREA TODAY, WHILE A FRONTAL BOUNDARY WILL
EXTEND SOUTHWARD INTO THE CAROLINA. ANOTHER LOW DEVELOPING ACROSS
THE DEEP SOUTH TODAY WILL LIFT NORTHWARD TONIGHT AND INTO THE GREAT
LAKES REGION WEDNESDAY INTO WEDNESDAY NIGHT. THE COASTAL FRONT WILL
BEGIN LIFTING NORTHWARD AS A WARM FRONT AND CROSS INTO THE AREA
WEDNESDAY, FOLLOWED BY A COLD FRONT WEDNESDAY NIGHT INTO THURSDAY
MORNING. HIGH PRESSURE WILL BUILD IN FROM THE SOUTH THURSDAY NIGHT
INTO FRIDAY NIGHT, BEFORE PUSHING BACK SOUTHWARD SATURDAY. AN AREA
OF LOW PRESSURE WILL MOVE INTO EASTERN CANADA THROUGH SATURDAY
NIGHT, PULLING A COLD FRONT ACROSS THE AREA BY SUNDAY MORNING. HIGH
PRESSURE WILL BUILD ACROSS NEW ENGLAND INTO EARLY NEXT WEEK, WHILE A
LOW PRESSURE MAY PASS JUST TO OUR SOUTH SUNDAY NIGHT INTO MONDAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE MID LEVEL PATTERN FOR TODAY FEATURES A TROUGH OVER THE MIDDLE
PART OF THE COUNTRY AND A RIDGE OVER THE WESTERN NORTH ATLANTIC.
WEAK IMPULSES ARE FORECAST TO PASS OVERHEAD IN THE SOUTHWEST FLOW
AND THEY MAY HELP TO TRIGGER SOME LIGHT RAIN AT TIMES.

THE SURFACE HIGH CENTERED OVER ATLANTIC CANADA WILL CONTINUE TO
RECEDE TODAY GRADUALLY LOSING ITS INFLUENCE OVER OUR REGION. WEAK
SURFACE LOW PRESSURE LOCATED OFF THE VIRGINIA CAPES AROUND 345 AM IS
EXPECTED TO DRIFT NORTHWARD TO A LOCATION OFF THE CENTRAL PART OF
THE NEW JERSEY COAST TOWARD EVENING.

THE LOW LEVELS OF THE ATMOSPHERE SHOULD CONTINUE TO MOISTEN TODAY
WITH WARM ADVECTION ALOFT. AS A RESULT, THE SKY IS FORECAST TO
REMAIN OVERCAST AND WE MAY SEE PATCHY DRIZZLE ALONG WITH THE AREAS
OF LIGHT RAIN. SOME FOG IS LIKELY IN THE ELEVATED TERRAIN.

THE LIGHT EAST NORTHEAST WIND THIS MORNING SHOULD BECOME VARIABLE
FOR THIS AFTERNOON AS THE CENTER OF THE LOW APPROACHES. TEMPERATURES
ARE EXPECTED TO RISE ONLY A FEW DEGREES WITH HIGHS IN THE 40S TO THE
NORTHWEST OF THE FALL LINE AND MAINLY IN THE LOWER 50S ON THE
COASTAL PLAIN.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM WEDNESDAY/...
LITTLE CHANGE IN THE OVERALL PATTERN IS EXPECTED FOR TONIGHT. THE
WEAK LOW OFF OUR COAST SHOULD DISSIPATE. WE ARE ANTICIPATING AN
OVERCAST SKY WITH SOME RAIN AND DRIZZLE. CEILINGS SHOULD LOWER
OVERNIGHT AND WE WILL LIKELY SEE AREAS OF FOG THROUGHOUT OUR REGION.
TEMPERATURES WILL CHANGE LITTLE DURING THE NIGHT AND THEY MAY
ACTUALLY BEGIN TO RISE A BIT TOWARD WEDNESDAY MORNING.

A WARM FRONT IS FORECAST TO LIFT TOWARD OUR REGION LATE TONIGHT AND
IT SHOULD REACH SOUTHERN DELAWARE AND THE ADJACENT COUNTIES OF
MARYLAND TOWARD DAYBREAK. RAINFALL RATES ARE EXPECTED TO INCREASE
LATE TONIGHT IN THE ISENTROPIC LIFT.

&&

.LONG TERM /WEDNESDAY THROUGH MONDAY/...
A WET START TO THE LONG TERM FORECAST, FOLLOWED BY A DRYING OUT
PERIOD FOR THE END OF THE WEEK, THEN SNOW POTENTIAL FOR THE END OF
THE WEEKEND?

THE LONG TERM STARTS OFF WITH AN EXTENDED PERIOD OF WET WEATHER
WEDNESDAY INTO WEDNESDAY NIGHT. AN AREA OF LOW PRESSURE DEVELOPING
ACROSS THE DEEP SOUTH TODAY WILL LIFT INTO THE GREAT LAKES WEDNESDAY
INTO WEDNESDAY NIGHT. WHILE DOING SO, A FRONTAL BOUNDARY ALONG THE
EAST COAST THAT EXTENDS TO OUR SOUTH WILL LIFT INTO THE AREA DURING
THE DAY WEDNESDAY. AMPLE LOW/MID LEVEL MOISTURE AND LIFT WILL MOVE
ACROSS THE AREA THROUGH THE DAY INTO THE NIGHT AND LEAD TO PERIODS
OF RAIN. NOT OVERLY EXCITED ABOUT THUNDERSTORM POTENTIAL, BUT
K-INDEX VALUES ARE IN THE LOW 30S AND TOTAL TOTALS APPROACH 44/45,
SO WOULD NOT BE TOO SURPRISED IF A FEW ISOLATED LIGHTNING STRIKES
OCCUR IN THE WARM SECTOR AS THE WARM FRONT LIFTS THROUGH THE AREA;
SO WE`VE EXPANDED THE ISOLATED THUNDER.

THE COLD FRONT APPROACHES FROM THE WEST DURING THE NIGHT WEDNESDAY,
AND SHOULD PUSH THROUGH BY THURSDAY MORNING. THERE REMAINS PLENTY OF
MOISTURE/LIFT ACROSS THE AREA SO PERIODS OF RAIN WILL CONTINUE
THROUGH THE NIGHT. THINK ANY THUNDER POTENTIAL SHOULD PUSH EASTWARD
DURING THE EVENING AS THE FRONT APPROACHES, SO SHIFTED ISOLATED
THUNDER ACROSS THE EASTERN HALF DURING THE EVENING.

ALL PRECIPITATION WILL FALL AS RAIN WEDNESDAY INTO WEDNESDAY NIGHT,
AND AMOUNTS ARE EXPECTED TO BE AROUND A HALF INCH TO AN INCH, WITH
SOME HIGHER AMOUNTS OF ONE AND A HALF INCHES POSSIBLE WEDNESDAY INTO
WEDNESDAY NIGHT. EVEN WITH THE HIGHER END OF THE EXPECTED RAINFALL,
IT SHOULD NOT CAUSE ANY FLOODING PROBLEMS, SO NO HEADLINES
ANTICIPATED.

THE FRONT WILL CONTINUE TO OUR EAST DURING THE DAY THURSDAY. SOME
SHOWERS ARE POSSIBLE EARLY IN THE MORNING AS THE FRONT PULLS OUT.
HOWEVER, THE MAIN CONCERN WITH THURSDAY WILL BE THE WINDS. SOUNDINGS
SHOW THE BEST POTENTIAL FOR WINDS TO BE AROUND 30-35 MPH, BUT IF
FULL MIXING OCCURRED, THERE COULD BE SOME GUSTS IN THE LOW 40S.
HOWEVER, STILL LOOKS TO BE BELOW ADVISORY LEVELS. THERE IS SOME
MOISTURE THAT SLIDES TO OUR NORTH DURING THE DAY ALONG WITH A SHORT
WAVE/VORT MAX, BUT LOW LEVEL LIFT IS LACKING. IT IS POSSIBLE THAT
SOME LAKE EFFECT SHOWERS WILL OCCUR TO OUR NORTH AND WEST, BUT NOT
CONFIDENT ON THEM REACHING OUR AREA, SO WILL LEAVE THEM OUT FOR NOW.

A DRYING OUT PERIOD IS EXPECTED THURSDAY NIGHT INTO SATURDAY AS HIGH
PRESSURE BUILDS IN FROM THE SOUTH THURSDAY NIGHT INTO FRIDAY NIGHT,
THEN PUSHES BACK SOUTHWARD SATURDAY.

A COLD FRONT IS EXPECTED TO MOVE INTO THE AREA SATURDAY NIGHT INTO
SUNDAY, ALTHOUGH THERE IS SOME TIMING AND STRENGTH DIFFERENCES WITH
THE GFS AND ECMWF. THE GFS IS FASTER AND DRIER, WHILE THE ECMWF AS
WETTER AND SLOWER. WITH THE UNCERTAINTY, WILL STILL NOT HIT THE
PRECIPITATION CHANCES HARD AND KEEP SLIGHT CHANCE TO CHANCE SATURDAY
NIGHT INTO SUNDAY. BOTH MODELS DEVELOP AN AREA OF LOW PRESSURE ALONG
THE FRONT AFTER IT SAGS SOUTH OF THE AREA INTO MONDAY, ALTHOUGH
THERE CONTINUES TO BE TIMING DIFFERENCES. THE GFS IS FURTHER SOUTH,
WHILE THE ECMWF IS FARTHER NORTH. WITH THE CONTINUING UNCERTAINTY,
WILL ONLY KEEP SLIGHT CHANCE TO CHANCE INTO SUNDAY NIGHT MONDAY. THE
THING TO NOTE IS WITH HIGH PRESSURE BUILDING TO THE NORTH, THERE
COULD BE ENOUGH COLD AIR THAT IF ANY PRECIPITATION DOES OCCUR THAT
IT COULD BE MORE SNOW THAN NOT. STILL A WAYS OUT, SO WE`LL SEE HOW
IT PROGRESSES IN THE DAYS TO COME.

&&

.AVIATION /08Z TUESDAY THROUGH SATURDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.

CONDITIONS WERE IFR AT KRDG, KABE, KTTN, KPNE AND KMIV AROUND 0845Z.
CONDITIONS WERE MVFR AT KPHL, KILG AND KACY.

LOW LEVEL MOISTURE WILL CONTINUE TO BUILD INTO OUR REGION AND IFR
CONDITIONS ARE EXPECTED TO SOLIDLY OVERSPREAD ALL OF OUR TAF SITES
BY 1100Z OR SO.

IT WILL BE A CHALLENGING DAY AND NIGHT FOR AVIATION INTERESTS, AS
IFR CONDITIONS ARE ANTICIPATED TO PREVAIL THROUGH THE TAF PERIOD.

A NORTHEAST TO EAST WIND AROUND 4 TO 8 KNOTS INTO THIS MORNING IS
EXPECTED TO BECOME LIGHT AND VARIABLE FOR THIS AFTERNOON AND THIS
EVENING. A LIGHT EAST WIND MAY DEVELOP LATE ON TUESDAY NIGHT.

OUTLOOK...
WEDNESDAY-WEDNESDAY NIGHT...SIGNIFICANTLY REDUCED CONDITIONS, MOST
LIKELY IFR/LIFR, WITH PERIODS OF RAIN, SOME HEAVY AT TIME. SOME
IMPROVEMENT POSSIBLE VERY LATE WEDNESDAY NIGHT.

THURSDAY...CONDITIONS IMPROVING TO VFR DURING THE MORNING. WEST
WINDS INCREASING AND GUSTY AT LEAST 25-30 KNOTS.

THURSDAY NIGHT-SATURDAY...MAINLY VFR. GUSTY SOUTHWEST WINDS 15-20
KNOTS SATURDAY.

&&

.MARINE...
THE PRESSURE GRADIENT BETWEEN THE WEAK LOW OFF THE MIDDLE ATLANTIC
COAST AND THE HIGH OVER EASTERN CANADA WAS MAINTAINING A STEADY EAST
NORTHEAST WIND ALONG OUR STRETCH OF THE COAST. WAVE HEIGHTS ON OUR
OCEAN WATERS RESPONDED AND THEY WERE IN THE 4 TO 6 FOOT RANGE AROUND
345 AM. WAVES ARE FORECAST TO REMAIN IN THAT RANGE INTO THIS MORNING
AS THE LOW MOVES NORTHWARD AND OVER OUR COASTAL WATERS. A VERY SLOW
DECREASE IN WAVE HEIGHTS IS EXPECTED FROM THIS AFTERNOON INTO
TONIGHT AS THE LOW DISSIPATES SLOWLY.

WE HAVE GONE WITH A SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS. IT IS
IN EFFECT FOR OUR OCEAN WATERS OFF DELAWARE AND OFF THE MOUTH OF
DELAWARE BAY UNTIL 600 PM. THE ADVISORY GOES UNTIL 200 AM WEDNESDAY
FOR OUR OCEAN WATERS OFF NEW JERSEY.

WIND SPEEDS ARE EXPECTED TO DECREASE AND THEY SHOULD BE 10 KNOTS OR
LESS FROM LATE THIS MORNING INTO TONIGHT.

OUTLOOK...
WEDNESDAY-WEDNESDAY NIGHT...WINDS AND SEAS EXPECTED INCREASE TO
SMALL CRAFT ADVISORY LEVELS DURING THE DAY AND CONTINUE INTO THE
NIGHT.

THURSDAY...SMALL CRAFT ADVISORY LEVELS REMAIN BEHIND A COLD FRONTAL
PASSAGE, WITH NEAR GALE FORCE WINDS POSSIBLE.

THURSDAY NIGHT...CONDITIONS WILL RETURN BELOW ADVISORY LEVELS
OVERNIGHT THURSDAY.

FRIDAY-SATURDAY...SUB-SMALL CRAFT ADVISORY LEVELS, ALTHOUGH WINDS
MAY GUST NEAR 20 KNOTS ON SATURDAY.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
     ANZ453>455.

&&

$$

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




USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.