Area Forecast Discussion
Issued by NWS Mt. Holly, NJ

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FXUS61 KPHI 120438
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1238 AM EDT SAT JUL 12 2014

.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE TO BUILD ACROSS THE NORTHEAST STATES
TONIGHT, THEN PUSH OFFSHORE SATURDAY. A WARM FRONT MAY TRY TO LIFT
ACROSS THE AREA SATURDAY NIGHT INTO SUNDAY. A PRE FRONTAL OR LEE
SIDE TROUGH WILL DEVELOP ACROSS THE MID ATLANTIC STATES MONDAY
INTO TUESDAY, BEFORE A COLD FRONT SWEEPS ACROSS THE AREA TUESDAY
INTO EARLY WEDNESDAY. HIGH PRESSURE WILL RETURN TO THE NORTHEAST
BY THE END OF NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
HIGH PRESSURE WILL CONTINUE TO BUILD INTO OUR REGION FROM THE
NORTH AND NORTHWEST DURING THE NIGHT. HOWEVER, A WEAK SOUTH TO
SOUTHEAST SURFACE FLOW WAS CONTINUING TO BRING A BIT OF MOISTURE
INTO OUR AREA. THE SKY WAS GENERALLY PARTLY CLOUDY OVER
NORTHEASTERN MARYLAND, DELAWARE, EASTERN PENNSYLVANIA AND NORTHERN
NEW JERSEY. THE SKY HAD BECOME MOSTLY CLOUDY OVER CENTRAL AND
SOUTHERN NEW JERSEY. THERE WERE A FEW SPRINKLES IN GLOUCESTER
COUNTY, CAMDEN COUNTY AND NORTHWESTERN BURLINGTON COUNTY. THE
CLOUDS AND SPRINKLES SHOULD LINGER THROUGH MUCH OF THE OVERNIGHT
IN CENTRAL AND SOUTHERN NEW JERSEY.

MEANWHILE, THERE WAS SOME STRATUS ALONG THE NORTHERN PART OF THE
NEW JERSEY SHORE AND IN EASTERN SUSSEX COUNTY, DELAWARE AROUND
MIDNIGHT, AGAIN DUE TO THE SOUTHEAST TO SOUTH SURFACE FLOW. A MORE
SUBSTANTIAL AREA OF STRATUS WAS DRIFTING WESTWARD TOWARD THE
SOUTHERN PART OF THE NEW JERSEY COAST. IT SHOULD ARRIVE SHORTLY
AFTER 100 AM.

MINIMUM TEMPERATURES SHOULD BE IN THE 60S IN MUCH OF OUR REGION
WITH SOME READINGS IN THE MIDDLE AND UPPER 5OS IN THE POCONOS AND
IN FAR NORTHERN NEW JERSEY.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM TODAY/...
THE HIGH WILL MOVE OFF THE NEW ENGLAND AND MID-ATLANTIC COAST
SATURDAY. SOUTHERLY RETURN FLOW AROUND THE HIGH WILL BE LIGHT OVER
THE FORECAST AREA SO DO NOT EXPECT A BIG SURGE OF WARM/MOIST AIR
BACK INTO THE REGION. LLVL THETA-E RIDGE DOES DRAW NORTHWARD INTO
CENTRAL PA, SO DIURNALLY-DRIVEN SHOWERS SHOULD STAY WEST OF THE
CWA. UNDER PLENTY OF SUNSHINE, MAX TEMPS ARE IN THE MID TO UPPER
80S EXCEPT COOLER NEAR THE WATERS AND IN THE POCONOS.

&&

.LONG TERM /TONIGHT THROUGH FRIDAY/...
A WET PERIOD CONTINUES TO LOOKS TO BE IN STORE EARLY NEXT WEEK,
ALTHOUGH THERE IS SOME DISAGREEMENT BETWEEN OPERATIONAL MODELS AND
HOW THEY HANDLE THE SYSTEM.

SATURDAY NIGHT IS FORECAST TO BE THE LAST DRY PERIOD IN THE FIRST
HALF OF THE LONG TERM FORECAST. THERE MAY BE A WARM FRONT LIFT
ACROSS THE AREA OVERNIGHT SATURDAY INTO SUNDAY MORNING, BUT FOR
NOW WE WILL KEEP DRY WEATHER ACROSS THE AREA.

THEN WE ENTER A PERIOD THROUGH AT LEAST TUESDAY WHEN WE HAVE A
CHANCE OF RAIN EACH PERIOD, DAY AND NIGHT. STARTING SUNDAY, A
SERIES OF FRONTAL BOUNDARIES WILL BEGIN MOVING OUT OF THE UPPER
MISSISSIPPI RIVER VALLEY AND INTO THE MIDWEST. AT THE SAME TIME, A
PRE-FRONTAL OR LEE-SIDE TROUGH WILL SET UP ACROSS THE MID-ATLANTIC
REGION. THE FRONTAL BOUNDARIES TO OUR WEST WILL SLOW DOWN INTO
MONDAY, BEFORE THE INITIAL ONE BEGINS TO TAKE OVER, WHILE THE
SURFACE TROUGH ACROSS THE MID-ATLANTIC REMAINS IN PLACE. SEVERAL
SHORT WAVE/VORTICITY IMPULSES WILL SWING AROUND THE MID-UPPER LOW
ACROSS THE GREAT LAKES REGION THROUGH THE PERIOD, KEEPING HIGH
CHANCES OF SHOWERS AND THUNDERSTORMS EACH PERIOD.

THE GFS AND ECMWF HAVE SPLIT IN THEIR SOLUTIONS IN REGARDS TO HOW
FAST THE FRONT MOVES THROUGH THE AREA. THE GFS IN ITS LATEST MODEL
RUN HAS SPEND THE FRONT UP AND MOVED IT THROUGH BY TUESDAY
MORNING, WHICH BASICALLY ENDS ALL PRECIPITATION BY TUESDAY.
MEANWHILE, THE ECMWF KEEPS THE FRONT SLOWLY MOVING INTO THE AREA
AND THROUGH LATE TUESDAY INTO WEDNESDAY MORNING WHICH IS MORE IN
LINE WITH PREVIOUS RUNS. FOR NOW WE ARE GOING TO KEEP CLOSER TO
WPC/ECMWF SOLUTION AND KEEP AN ENHANCED CHANCE OF SHOWERS AND
THUNDERSTORMS THROUGH TUESDAY NIGHT.

DURING THE SUNDAY THROUGH TUESDAY PERIOD, THERE WILL BE THE
THREAT FOR VERY HEAVY RAINFALL WITH FLOODING POSSIBLE AS PW VALUES
WILL BE NEAR OR OVER 2 INCHES. IN ADDITION, WITH THE WARM/UNSTABLE
AIR MASS IN PLACE, DEPENDING ON THE MID-UPPER JET DYNAMICS AND
FORECAST SHEAR, THERE COULD BE A PERIOD OF STRONG TO SEVERE
STORMS. MONDAY AND TUESDAY LOOK TO BE THE PERIOD OF HIGHEST
STRONG/SEVERE THREAT.

REGARDLESS OF WHICH SOLUTION IS RIGHT, WE EXPECT A DRYING OUT
PERIOD STARTING LATE WEDNESDAY INTO THURSDAY AS PW VALUES LOWER TO
AN INCH OR LESS ACROSS THE AREA AND HIGH PRESSURE BUILDS BACK
ACROSS THE NORTHEAST. HOWEVER, ISOLATED SHOWERS AND THUNDERSTORMS
MAY RETURN BY FRIDAY AS RETURN FLOW DEVELOPS AND MOISTURE BEGINS
TO CREEP BACK NORTHWARD.

AFTER ABOVE NORMAL TEMPERATURES FOR THE FIRST HALF OF THE
EXTENDED SUNDAY-TUESDAY, NEAR OR EVEN SLIGHTLY BELOW NORMAL
TEMPERATURES COULD RETURN FOR THE SECOND HALF OF NEXT WEEK.

&&

.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.

PATCHY FOG POSSIBLE BETWEEN 06Z-12Z AT THE TERMINALS TO THE SOUTH
AND WEST OF KPHL. IFR CIGS IN STRATUS ARE EXPECTED AT ACY/MIV. VFR
DURING THE DAYTIME HOURS SATURDAY WITH HIPRES JUST OFFSHORE.

OUTLOOK...
SATURDAY NIGHT...MOSTLY VFR.

SUNDAY-MONDAY...GENERALLY VFR WITH A CHANCE FOR SHOWERS AND
THUNDERSTORMS. LOCALLY MVFR/IFR CONDITIONS POSSIBLE WITH SHOWERS
OR THUNDERSTORMS. GUSTY AFTERNOON WINDS 15-20 KNOTS.

TUESDAY-TUESDAY NIGHT...SHOWERS AND THUNDERSTORMS EXPECTED WITH A
COLD FRONTAL PASSAGE. MVFR/IFR CONDITIONS LIKELY WITH SHOWERS OR
THUNDERSTORMS. GUSTY WINDS IN THE AFTERNOON AROUND 20 KNOTS, WITH
STRONGER WIND GUSTS POSSIBLE WITH THUNDERSTORMS.

WEDNESDAY...SHOWERS AND THUNDERSTORMS POSSIBLE IN THE MORNING,
THEN CLEARING THROUGH THE DAY.

&&

.MARINE...
EASTERLY WINDS 5-10 KT BECOMING SOUTH-SOUTHEASTERLY TONIGHT AND
SOUTHERLY SATURDAY MORNING AS HIPRES MOVES OFF THE COAST. WINDS
WILL BE LIGHT DURING THIS TIME. SOUTHERLY FLOW STRENGTHENS
SATURDAY AFTERNOON BUT WILL BE BELOW SCA LEVELS WITH GUSTS AROUND
15 KT.

OUTLOOK...
SUNDAY-TUESDAY NIGHT...NEAR OR LOWER END SMALL CRAFT ADVISORY
CONDITIONS ARE POSSIBLE THROUGH THE OUTLOOK PERIOD AS SOUTHWEST
WINDS INCREASE AHEAD OF AN APPROACHING COLD FRONT AND HIGH
PRESSURE REMAINS WELL OFF THE COAST.

WEDNESDAY...NEAR SMALL CRAFT POSSIBLE EARLY IN THE DAY WITH GUSTY
WINDS BEHIND FRONTAL BOUNDARY, THEN DIMINISHING THROUGH THE DAY.

&&

.TIDES/COASTAL FLOODING...
THE HIGH TIDES FRIDAY NIGHT, SATURDAY NIGHT, AND SUNDAY NIGHT MAY
APPROACH THE MINOR FLOOD LEVEL ALONG THE ATLANTIC COASTAL AREAS,
BUT ARE NOT EXPECTED TO REACH HIGH ENOUGH LEVELS TO REQUIRE A
COASTAL FLOOD ADVISORY.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.

&&

$$

SYNOPSIS...ROBERTSON
NEAR TERM...IOVINO
SHORT TERM...KLEIN
LONG TERM...ROBERTSON
AVIATION...KLEIN/ROBERTSON
MARINE...KLEIN/ROBERTSON
TIDES/COASTAL FLOODING...ROBERTSON





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