Area Forecast Discussion
Issued by NWS Mt. Holly, NJ

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000
FXUS61 KPHI 040918
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
418 AM EST WED MAR 4 2015

.SYNOPSIS...
A COLD FRONT...ATTACHED TO LOW PRESSURE ACROSS CANADA...WILL CROSS
THE AREA TODAY AND STALL TO THE SOUTH TONIGHT. LOW PRESSURE WILL
MOVE ALONG THE FRONT TONIGHT THROUGH THURSDAY NIGHT. HIGH PRESSURE
WILL BUILD IN FOR FRIDAY AND SATURDAY. A WEAK DISTURBANCE WILL PASS
NORTH OF THE AREA SATURDAY NIGHT. MORE HIGH PRESSURE WILL ARRIVE FOR
EARLY NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A COLD FRONT WILL DROP SLOWLY THROUGH OUR REGION FROM THE NORTHWEST
TODAY. LOW PRESSURE IS FORECAST TO DEVELOP ALONG THE BOUNDARY IN THE
SOUTHEASTERN STATES AND IT SHOULD BE LOCATED IN NORTH CAROLINA BY
EVENING.

LOW LEVEL MOISTURE WILL LINGER IN OUR REGION TODAY WITH OCCASIONAL
RAIN. TEMPERATURES WILL REMAIN BELOW FREEZING IN SPOTS IN THE LEHIGH
VALLEY, THE POCONOS AND NORTHERN NEW JERSEY EARLY THIS MORNING. AS A
RESULT, THE WINTER WEATHER ADVISORY WILL REMAIN IN PLACE FOR PATCHY
FREEZING RAIN AND FREEZING DRIZZLE THERE.

TEMPERATURES ARE FORECAST TO REMAIN IN THE 30S IN OUR NORTHERN
COUNTIES FOR TODAY AND THEY SHOULD RISE INTO THE 40S IN THE SOUTH. A
LIGHT SOUTHWEST WIND IS ANTICIPATED TO BECOME WEST THEN NORTHWEST.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/...
THE COLD FRONT WILL CONTINUE TO SINK SLOWLY TO OUR SOUTH DURING
TONIGHT AND THURSDAY AS WAVES OF LOW PRESSURE MOVE ALONG IT. ARCTIC
AIR WILL BEGIN TO FILTER INTO OUR REGION FROM THE NORTHWEST AS
PRECIPITATION RIDES NORTHEASTWARD ALONG THE FRONT. WE CONTINUE TO
EXPECT A SIGNIFICANT SNOWFALL FOR OUR FORECAST AREA. TEMPERATURES
ARE ANTICIPATED TO FALL THROUGH THE 30S TONIGHT AND INTO THE 20S FOR
THURSDAY IN MUCH OF OUR REGION.

PERIODS OF RAIN WILL TRANSITION THROUGH SLEET TO SNOW FROM NORTH TO
SOUTH IN OUR REGION TONIGHT. THE PRECIPITATION TYPE SHOULD BE ALL
SNOW IN OUR REGION FOR THURSDAY.

WE HAVE UPGRADED THE WINTER STORM WATCH TO A WINTER STORM WARNING
FOR ALL BUT THE LEHIGH VALLEY, THE POCONOS AND NORTHERN NEW JERSEY.

WE ARE ANTICIPATING SNOWFALL TOTALS GENERALLY IN THE 5 TO 9 INCH
RANGE IN THE WARNING AREA BASED ON THE LATEST GUIDANCE. WE MAY SEE
SLIGHTLY LOWER AMOUNTS IN SOUTHERN DELAWARE, PERHAPS IN THE 3 TO 7
INCH RANGE.

THERE REMAINS SOME UNCERTAINTY AS TO WHETHER OUR NORTHERN COUNTIES
WILL REACH THEIR 6 INCH SNOWFALL CRITERION FOR A WARNING. WE WILL
KEEP THE WINTER STORM WATCH GOING THERE FOR A BIT LONGER.

THE SNOW IS ANTICIPATED TO END FROM NORTHWEST TO SOUTHEAST ON
THURSDAY AFTERNOON AS DRY AIR BEGINS TO BUILD INTO OUR REGION.

&&

.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
THE END OF THE STORM EARLY THURSDAY NIGHT WITH THE STEADY SNOWS
MOVING OFF THE E/SE AREAS EARLY. A CHC POP FOR THE BEGINNING FEW
HOURS OF THE OVERNIGHT PERIOD. CLEARING ADVANCES FROM N/W TO S/E
OVERNIGHT. COLD WITH LOWS IN THE SINGLE DIGITS MOST AREAS. WIND
CHILLS BELOW ZERO BY DAWN...PERHAPS AS LOW AS -12 TO -15 FAR
NORTH.

FRI/FRI NIGHT...FAIR WEATHER WITH HIGH PRESSURE ACROSS THE AREA.
TEMPERATURES REMAIN SOLIDLY BELOW NORMAL. HIGHS IN THE MID/UPPER
20S. NORMAL HIGHS FOR EARLY MARCH ARE 20 OR SO DEGREES ABOVE
THAT.

SAT/SAT NIGHT...FAIR WEATHER ACROSS MOST AREAS. A FEW SNOW SHOWERS
POSSIBLE ACROSS THE SOUTHERN POCONOS. TEMPERATURES MODERATING...BUT
STILL 10 OR SO DEGREES BELOW NORMAL.

SUN/SUN NIGHT...FAIR WEATHER WITH TEMPS A LITTLE BELOW NORMAL.

MON/MON NIGHT...FEW SNOW SHOWERS POSSIBLE EARLY WITH A WEAK
LOW/FRONT CROSSING THE REGION. POPS IN THE SLGT CHC RANGE ATTM.
TEMPS SLIGHTLY BELOW NORMAL. FAIR WEATHER MON NIGHT.

TUE...FAIR WEATHER WITH TEMPS NEAR NORMAL. HIGHS CLOSE TO 50
DEGREES POSSIBLE ACROSS THE DELMARVA AND METRO PHILLY.

&&

.AVIATION /09Z WEDNESDAY THROUGH SUNDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.

CONDITIONS WILL FAVOR IFR TODAY WITH PERHAPS A BRIEF IMPROVEMENT TO
MVFR AT TIMES. THERE WILL BE PERIODS OF RAIN.

CONDITIONS SHOULD BE IFR FOR TONIGHT AS RAIN BECOME STEADIER THIS
EVENING. COLD AIR WILL BUILD DOWN FROM THE NORTHWEST AND NORTH AND
THE RAIN WILL TRANSITION THROUGH SLEET TO SNOW. A SIGNIFICANT SNOW
ACCUMULATION IS ANTICIPATED FOR WEDNESDAY NIGHT INTO THURSDAY AND IT
WILL HAVE AN IMPACT ON THE AIRFIELDS.

A LIGHT WIND SHOULD VEER FROM THE SOUTHWEST TO THE NORTHWEST TODAY.
THE WIND IS FORECAST TO FAVOR THE NORTHWEST AND NORTH FOR TONIGHT
AROUND 6 TO 12 KNOTS.

THE LOW LEVEL SOUTHWESTERLY JET THAT WAS OVERHEAD EARLY THIS MORNING
WILL SHIFT TO THE SOUTHEAST AND WE SHOULD NOT HAVE ANY ADDITIONAL
CONCERN FOR LOW LEVEL WIND SHEAR AFTER ABOUT 1000Z OR 1100Z.

OUTLOOK...
THURSDAY...IFR WITH SIGNIFICANT SNOWFALL.
THURSDAY NIGHT...CONDITIONS RETURNING TO VFR OVERNIGHT.
FRIDAY THRU SUNDAY...MOSTLY VFR.

&&

.MARINE...
THE BRIEF PERIOD OF NEAR 25 KNOT WIND GUSTS SHOULD COME TO AN END BY
DAYBREAK. AS A RESULT, WE WILL ALLOW THE SMALL CRAFT ADVISORY TO
EXPIRE AT 600 AM

A SOUTHWEST WIND AROUND 10 TO 15 KNOTS THIS MORNING SHOULD BACK TO
THE WEST, THEN TO THE NORTHWEST AROUND 10 KNOTS TODAY AS A COLD
FRONT SINKS THROUGH OUR REGION. THE WIND IS EXPECTED TO SETTLE INTO
THE NORTHWEST AND NORTH FOR TONIGHT AROUND 10 TO 15 KNOTS.

OUTLOOK..
THU/THU NIGHT...SCA WINDS AND SEAS EXPECTED.
FRI THRU SUN...MOSTLY SUB-SCA CONDITIONS.

&&

.HYDROLOGY...
PLEASE MONITOR LATEST QPF FCSTS FROM WPC AND MARFC.

THE FORECASTS CONTINUE TO SHOW A DECENT AMOUNT OF QPF ACROSS THE
AREA TONIGHT AND INTO THURSDAY. A CHANGEOVER TO SLEET OR SNOW
ISN`T EXPECTED TO OCCUR UNTIL EARLY THURSDAY MORNING ACROSS THE
SOUTHERN AREAS.

WHILE THERE ISN`T MUCH OF A SNOWPACK ACROSS THE SOUTHERN HALF OF
OUR CWA, THE GROUND IS FROZEN, AND ANY RUNOFF WILL BE VERY
EFFICIENT.

IF THE 0.75 TO 1.00 INCHES OF QPF MATERIALIZES, WE FEEL NUISANCE
POOR DRAINAGE AND LOW LYING FLOODING WILL BE THE MOST LIKELY
OUTCOME. MODELED SOLUTIONS SUGGEST WE WOULD NEED ABOUT 2.50 INCHES
OF LIQUID, EITHER IN THE FORM OF ALL RAIN OR RAIN AND MELTING SNOW
TO HAVE OUR SOUTHERN CREEKS AND STREAMS LEAVE THEIR BANKS.

WITH MORE SNOW OR SLEET EXPECTED ACROSS THE NORTHERN HALF OF THE
CWA, WE`RE NOT CONCERNED ABOUT FLOODING THERE.

WITH THE RAINFALL, THE FLOW ON AREA CREEKS AND STREAMS WILL
INCREASE. THIS COULD START TO MOVE ICE, AND IN A WORST CASE
SCENARIO, CREATE RESTRICTIONS OR JAMS.

CONTINUE TO MONITOR THE FORECAST. KEEP IN MIND THAT SNOWMELT AND
THE WARMER TEMPERATURES EXPECTED TODAY, BY THEMSELVES, WOULD NOT
CAUSE FLOODING. THE AMOUNT OF RAIN THAT WE RECEIVE WILL BE THE
DETERMINING FACTOR.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...WINTER WEATHER ADVISORY UNTIL 6 AM EST EARLY THIS MORNING FOR
     PAZ061-062.
     WINTER STORM WATCH FROM THIS EVENING THROUGH THURSDAY EVENING
     FOR PAZ054-055-061-062.
     WINTER STORM WARNING FROM 7 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR PAZ060-101>106.
     WINTER STORM WARNING FROM 11 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR PAZ070-071.
     WINTER WEATHER ADVISORY UNTIL 9 AM EST THIS MORNING FOR PAZ054-
     055.
NJ...WINTER WEATHER ADVISORY UNTIL 6 AM EST EARLY THIS MORNING FOR
     NJZ007-008.
     WINTER STORM WATCH FROM THIS EVENING THROUGH THURSDAY EVENING
     FOR NJZ001-007-008.
     WINTER STORM WARNING FROM 7 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR NJZ009-010-012-015.
     WINTER STORM WARNING FROM 11 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR NJZ013-014-016>027.
     WINTER WEATHER ADVISORY UNTIL 9 AM EST THIS MORNING FOR NJZ001.
DE...WINTER STORM WARNING FROM 11 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR DEZ001-002.
     WINTER STORM WARNING FROM 3 AM TO 7 PM EST THURSDAY FOR DEZ003-
     004.
MD...WINTER STORM WARNING FROM 11 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR MDZ008-012-015-019-020.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST EARLY THIS MORNING FOR
     ANZ450>455.

&&

$$
SYNOPSIS...O`HARA
NEAR TERM...IOVINO
SHORT TERM...IOVINO
LONG TERM...O`HARA
AVIATION...IOVINO/O`HARA
MARINE...IOVINO/O`HARA
HYDROLOGY...KRUZDLO/O`HARA


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