Special Weather Statement, NWS Philadelphia/Mount Holly

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1234 PM EDT SAT SEP 12 2015

.SYNOPSIS...
BROAD LOW PRESSURE EXTENDING FROM WESTERN PENNSYLVANIA TO CENTRAL
VIRGINIA AROUND MIDDAY WILL DRIFT NORTHEASTWARD AND IT SHOULD
REACH NEW ENGLAND AND SOUTHERN QUEBEC ON SUNDAY. HIGH PRESSURE
OVER THE CENTRAL APPALACHIANS MONDAY WILL SLOWLY BUILD INTO THE
MID ATLANTIC STATES DURING MID WEEK, THEN OFFSHORE BY NEXT
WEEKEND.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
BROAD LOW PRESSURE EXTENDING FROM WESTERN PENNSYLVANIA TO CENTRAL
VIRGINIA AROUND MIDDAY WILL DRIFT TO THE NORTHEAST AND EAST TOWARD
OUR REGION TODAY. AN AREA OF RAIN SHOWERS AND EMBEDDED
THUNDERSTORMS WAS LOCATED AHEAD OF THE LOW FROM CENTRAL AND
EASTERN PENNSYLVANIA INTO THE CHESAPEAKE BAY REGION.

A WARM FRONT EXTENDED FROM CENTRAL VIRGINIA TO THE WATERS OFF THE
LOWER DELMARVA PENINSULA. THE BOUNDARY IS ANTICIPATED TO LIFT
NORTHWARD AND INTO NORTHEASTERN MARYLAND, DELAWARE AND SOUTHERN
NEW JERSEY DURING THE LATE AFTERNOON.

PRECIPITATION WILL CONTINUE TO SPREAD INTO OUR FORECAST AREA
DURING THE AFTERNOON HOURS. SHOWERS AND ISOLATED THUNDERSTORMS ARE
EXPECTED. THE RAIN MAY BECOME MODERATE TO HEAVY AT TIMES WITH
LOCALIZED FLOODING IN AREAS OF POOR DRAINAGE POSSIBLE.

THE STORM PREDICTION CENTER HAS OUR REGION UNDER ITS MARGINAL
RISK DESIGNATION FOR SEVERE WEATHER. THERE SHOULD BE ENOUGH SHEAR,
ESPECIALLY IN THE VICINITY OF THE WARM FRONT, TO POSSIBLY PRODUCE
ORGANIZED STORMS WITH THE POTENTIAL FOR SOME STRONG WIND GUSTS.
NEVERTHELESS, THE THREAT FOR SEVERE WEATHER SHOULD BE LOCALIZED.

MAXIMUM TEMPERATURES ARE FORECAST TO BE MAINLY IN THE 70S AND
LOWER 80S. READINGS SHOULD FALL A BIT WITH THE ARRIVAL OF THE
RAIN SHOWERS. THE SURFACE WIND SHOULD FAVOR THE EAST TO SOUTH
QUADRANT.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SUNDAY/...
THE LOW WILL CONTINUE TO SLOWLY DEEPEN AS THE UPPER TROUGH/LOW
CONTINUES TO DIG ACROSS THE OHIO VALLEY. THE AXIS OF THE TROUGH
(TWO SEPARATE LOW CENTERS) CROSSES THE AREA OVERNIGHT. THE STEADY
RAINS AND SCT TSTMS WILL DIMINISH LATE TONIGHT FROM S/W TO N/E AND
WINDS WILL SHIFT TO SWRLY OR WRLY LATE. TOTAL RAINFALL TODAY AND
TONIGHT SHOULD BE AROUND 3/4 INCH NORTH AND CLOSER TO 1/2 INCH
ACROSS THE REST OF THE AREA. LOW TONIGHT WILL DROP INTO THE 60S
MOST AREAS AND UPPER 50S ACROSS THE FAR NORTH.

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
500 MB: A SHARPENING TROUGH IN THE OHIO VALLEY SUNDAY BRIEFLY
CLOSES OFF AS IT LIFTS NEWD INTO NYS MONDAY THEN WEAKENS INTO THE
MARITIMES TUESDAY. STRONG RIDGING FOLLOWS DURING THE MIDDLE OF
NEXT WEEK AND ABOVE NORMAL HEIGHTS LINGER INTO NEXT WEEKEND AS THE
SUMMER PATTERN RESUMES.

TEMPERATURES: THE FIRST 11 DAYS HAVE AVERAGED ABOUT 5 TO 8.5
DEGREES ABOVE NORMAL. THE CALENDAR DAY AVERAGE ON SUNDAY WILL BE
NEAR NORMAL, THEN SEVERAL DEGREES BELOW NORMAL MONDAY BEFORE
WARMING TO NEAR NORMAL TUESDAY AND AROUND 5 DEGREES ABOVE NORMAL
EACH DAY WEDNESDAY ONWARD.

FORECAST BASIS: UNLESS OTHERWISE NOTED, A 50 50 BLEND 00Z/12
GFS/NAM MOS GUIDANCE SUNDAY-MONDAY EXCEPT FAVORED THE WARMER GFS
MOS SUNDAY BECAUSE OF THE WARM GFS 2M TEMPS, THEN 00Z/12 GFS MEX
MOS MONDAY NIGHT AND TUESDAY, THEREAFTER THE 0521Z/12 WPC GRIDDED
ELEMENTS OF MAX/MIN TEMP BLENDED 50 50 WITH THE GFS MEX MOS FOR
THE MINS AND USED ONLY THE GFS MOS MAX'S DURING THE DAY, OR EVEN
RAISED THAT 2 DEGREES (GUIDED BY THE 2M TEMPS). WPC GRIDS WERE
USED FOR THE 12 HOUR POP, 6 HOUR DEW POINT- SKY- WIND FROM
TUESDAY NIGHT ONWARD.

MAXIMUM TEMPERATURES WEDNESDAY-FRIDAY SHOULD RUN AS MUCH AS 10
DEGREES ABOVE NORMAL EACH DAY OVER THE INTERIOR.

REGARDING WARMING THE GUIDANCE: ITS A DRY SUMMER PATTERN AND
LOOKS LOADED WITH SUNSHINE. THE MEX GUIDANCE HAS BEEN BIASED ON
THE COOL SIDE THE PAST SEVERAL WEEKS OF SUNNY DAYS. SO A
COMBINATION OF OPERATIONAL EC/GFS 2M BLENDED TEMPS PLUS 4F SEEMS
TO WORK WELL AS AN ACCURATE PREDICTOR OF NON MARINE INFLUENCED MAX
TEMPS.

NOTICED IN THE HEAT WAVES THAT WHENEVER GFS 2M TEMPS HAD 92 OR 95
IN SE PA WESTERN NJ, THOSE VALUES OCCURRED I-95 NWWD.

HYDRO-RAIN: WHATEVER WE GET TODAY THROUGH SUNDAY IS PROBABLY ALL
WE RECEIVE BEFORE NEXT WEEKEND SO THAT WE RESUME AN EXTENDED DRY
SPELL MON-FRI.

THE DAILIES...

SUNDAY...THE 60M 500MB HFC MOVING INTO NJ LATE IN THE DAY
ASSOCIATED WITH THE APPROACHING MID LVL TROUGH, COMBINING WITH
LEFTOVER MOISTURE FROM TODAY'S INFLOW AND GENERAL LOW LVL
CONVERGENCE ASSOCIATED WITH SFC PRES PATTERN SHOULD RESULT IN A
BAND OR TWO OF SHOWERS AND POSSIBLE ISOLATED LOW TOP TSTMS.
DAYTIME MAX TEMPERATURES NEAR NORMAL. 200-400J MLCAPE IN NNJ AND
NE PA N OF KPTW-KTTN. IF THUNDER OCCURS, WE MIGHT HAVE OURSELVES A
NOTABLE 40 KT WSW WIND GUST ALONG OR N OF I-78. ITS CONDITIONAL ON
TSTMS DEVELOPING AND RIGHT NOW CONFIDENCE ON THUNDER OCCURRING IS
BELOW AVG AS IS CONFIDENCE ON POPS. TEMPS MIGHT BE A DEGREE OR 2
ON THE WARM SIDE? A WESTERLY WIND DEVELOPS WITH GUSTS TO 20 MPH
DURING THE AFTERNOON.

SUNDAY NIGHT...STILL A POSSIBLE WRAPAROUND SHOWER IN NE PA AND NW
NJ WITH HIGH TT/KI BUT OTHERWISE, PARTIAL CLEARING. A GUSTY WNW
WIND TO 15 MPH. CONFIDENCE: ABOVE AVERAGE.

MONDAY...PARTLY SUNNY, BREEZY AND LESS HUMID. WNW WIND GUSTY TO
25 MPH.

MONDAY NIGHT ...MOSTLY CLEAR.

TUESDAY...SUNNY AND WARMER. STILL A NW WIND.

WEDNESDAY...SUNNY AND WARM. LIGHT NW WIND.

THURSDAY...SUNNY AND WARMER. LIGHT WEST WIND. AFTERNOON COASTAL
SEA BREEZES?

FRIDAY...PATCHY FOG EARLY? OTHERWISE M/SUNNY AND WARM. SW WIND.

&&

.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY, AND SURROUNDING AREAS.

CLOUDS WILL LOWER AND VSBYS WILL BECOME REDUCED IN SHOWERS THIS
AFTERNOON...SMALL CHC FOR THUNDER (EXCLUDED FROM TAFS HOWEVER).
STAT GUIDANCE HIGHLY VARIABLE WITH REGARDS TO CIGS/VSBYS THIS TIME
AROUND. TENDED TO USE PREVIOUS FCST WITH SOME MINOR TWEAKS IN A
FEW AREAS. FRONT/LOWS WILL CROSS AREA SAT NIGHT/EARLY SUNDAY WITH
WINDS SHIFTING BACK TO WRLY/SWRLY AND STEADY RAINS/SHOWERS ENDING
BEHIND IT.

OUTLOOK...
SUNDAY...MAINLY VFR CIGS WITH A BAND OR TWO OF SHOWERS AND
POSSIBLE ISOLATED TSTMS. BRIEF MVFR CONDS IN SHOWERS AND ALSO IN
WRAPAROUND LOW CLOUDS DOWN TOWARD KABE. WIND TURNING WEST AND
GUSTING TO 20 KT DURING THE AFTERNOON. CONFIDENCE: AVERAGE.

SUNDAY NIGHT...VFR SCT-BKN AOA 5000FT. NW WIND GUST 15-20 KT.
CONFIDENCE ABOVE AVERAGE:

MONDAY...VFR SCT TO POSSIBLY BKN AOA 5000 FT. NW WIND GUSTY 20-25
KT. CONFIDENCE: ABOVE AVERAGE.

TUESDAY...VFR CLEAR OR SCT CLOUDS AOA 5000 FT. NW WIND.
CONFIDENCE: ABOVE AVERAGE.

WEDNESDAY...VFR CLEAR OR SCT CLOUDS AOA 5000 FT. LIGHT NW WIND.
CONFIDENCE: ABOVE AVERAGE.

&&

.MARINE...
WEAK HIGH PRESSURE TO THE EAST THIS MORNING WILL MOVE AWAY WHILE
LOW PRESSURE DEEPENS AND MOVES ACROSS THE REGION TONIGHT. THE
WATERS WILL EXPERIENCE AN INCREASE IN WIND SPEEDS FROM THE SE
TODAY THEN A SWITCH IN WINDS TO SWRLY SUN MORNING. WIND SPEEDS ARE
EXPECTED TO REMAIN BELOW SCA CONDITIONS THRU SUN MORNING. SHOWERS
WILL ARRIVE THIS AFTERNOON AND THEN REMAIN ACROSS THE WATERS MUCH
OF TONIGHT. ISOLATED TSTMS WITH GUSTY WINDS POSSIBLE.

OUTLOOK...
SUNDAY...PROBABLY SUB ADVISORY DURING THE DAY WITH A BAND OR TWO
OF SHOWERS AND POSSIBLY A GUSTY TSTM. WINDS TURN W DURING THE
AFTERNOON AND GUST 20-25 KT BY DAYS END. CONFIDENCE: AVERAGE.

SUNDAY NIGHT...NW WIND GUSTY 20 KT, POSSIBLY ADVISORY LVL 25 KT.
AN SCA FOR WIND MAY BE NEEDED? CONFIDENCE: AVERAGE.

MONDAY...NW WIND GUSTY AROUND 20 KT. CONFIDENCE: ABOVE AVERAGE.

TUESDAY AND WEDNESDAY...SUB-ADVISORY CONDITIONS ARE EXPECTED WITH
HIGH PRESSURE ACROSS THE REGION. CONFIDENCE: ABOVE AVERAGE.

&&

.RIP CURRENTS...
A STRENGTHENING SOUTHEASTERLY FLOW, THE APPROACHING NEW MOON ON
SUNDAY AND 2-3 FT MEDIUM PERIOD SWELLS WILL ENHANCE THE RISK FOR
THE FORMATION OF DANGEROUS RIP CURRENTS. FOLLOWED IN-HOUSE
STATISTICAL GUIDANCE CLOSELY, WHICH GIVES US A MODERATE RISK FOR
TODAY.

THE RISK OF RIP CURRENT FORMATION MAY CONTINUE TO BE MODERATE
SUNDAY WITH A DEVELOPING 4 FOOT SHORT PERIOD SOUTHERLY SWELL. WIND
DIRECTION WILL BE THE DETERMINING FACTOR.

&&

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

&&

SYNOPSIS...DRAG
NEAR TERM...IOVINO
SHORT TERM...O'HARA
LONG TERM...DRAG
AVIATION...DRAG/O'HARA
MARINE...DRAG/O'HARA
RIP CURRENTS...STAFF

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
932 AM EDT SAT SEP 12 2015

DEZ001>003-MDZ008-012-015-019-020-NJZ001-007>010-012-013-015>023-027-
PAZ054-055-060>062-070-071-101>106-131345-
NEW CASTLE-KENT-INLAND SUSSEX-CECIL-KENT MD-QUEEN ANNES-TALBOT-
CAROLINE-SUSSEX-WARREN-MORRIS-HUNTERDON-SOMERSET-MIDDLESEX-
WESTERN MONMOUTH-MERCER-SALEM-GLOUCESTER-CAMDEN-
NORTHWESTERN BURLINGTON-OCEAN-CUMBERLAND-ATLANTIC-CAPE MAY-
SOUTHEASTERN BURLINGTON-CARBON-MONROE-BERKS-LEHIGH-NORTHAMPTON-
DELAWARE-PHILADELPHIA-WESTERN CHESTER-EASTERN CHESTER-
WESTERN MONTGOMERY-EASTERN MONTGOMERY-UPPER BUCKS-LOWER BUCKS-
932 AM EDT SAT SEP 12 2015

THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL DELAWARE...NORTHERN
DELAWARE...SOUTHERN DELAWARE...NORTHEAST MARYLAND...CENTRAL NEW
JERSEY...NORTHERN NEW JERSEY...NORTHWEST NEW JERSEY...SOUTHERN NEW
JERSEY...EAST CENTRAL PENNSYLVANIA...NORTHEAST PENNSYLVANIA AND
SOUTHEAST PENNSYLVANIA.

.DAY ONE...TODAY AND TONIGHT.

SHOWERS AND THUNDERSTORMS PRODUCING HEAVY RAIN MAY LEAD TO POCKETS
OF BRIEF FLOODING IN URBAN, POOR DRAINAGE, AND LOW LYING AREAS
THIS AFTERNOON AND EVENING. IN ADDITION, THUNDERSTORMS COULD
PRODUCE STRONG GUSTY WINDS.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY.

THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.

DEZ004-NJZ014-024>026-131345-
DELAWARE BEACHES-EASTERN MONMOUTH-ATLANTIC COASTAL CAPE MAY-
COASTAL ATLANTIC-COASTAL OCEAN-
932 AM EDT SAT SEP 12 2015

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTHERN DELAWARE...CENTRAL
NEW JERSEY AND SOUTHERN NEW JERSEY.

.DAY ONE...TODAY AND TONIGHT.

THERE IS A MODERATE RISK FOR THE FORMATION OF DANGEROUS RIP
CURRENTS TODAY ALONG THE NEW JERSEY COAST.

SHOWERS AND THUNDERSTORMS PRODUCING HEAVY RAIN MAY LEAD TO POCKETS
OF BRIEF FLOODING IN URBAN, POOR DRAINAGE, AND LOW LYING AREAS
THIS AFTERNOON AND EVENING. IN ADDITION, THUNDERSTORMS COULD
PRODUCE STRONG GUSTY WINDS.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY.

THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.

ANZ430-431-450>455-131345-
DELAWARE BAY WATERS NORTH OF EAST POINT NJ TO SLAUGHTER BEACH DE-
DELAWARE BAY WATERS SOUTH OF EAST POINT NJ TO SLAUGHTER BEACH DE-
COASTAL WATERS FROM SANDY HOOK TO MANASQUAN INLET NJ OUT 20 NM-
COASTAL WATERS FROM MANASQUAN INLET TO LITTLE EGG INLET NJ OUT 20 NM-
COASTAL WATERS FROM LITTLE EGG INLET TO GREAT EGG INLET NJ OUT 20 NM-
COASTAL WATERS FROM GREAT EGG INLET TO CAPE MAY NJ OUT 20 NM-
COASTAL WATERS FROM CAPE MAY NJ TO CAPE HENLOPEN DE OUT 20 NM-
COASTAL WATERS FROM CAPE HENLOPEN TO FENWICK ISLAND DE OUT 20 NM-
932 AM EDT SAT SEP 12 2015

THIS HAZARDOUS WEATHER OUTLOOK IS FOR ATLANTIC COASTAL WATERS AND
DELAWARE BAY WATERS.

.DAY ONE...TODAY AND TONIGHT.

A FEW THUNDERSTORMS THIS AFTERNOON AND EVENING MAY PRODUCE LOCALLY
STRONG WINDS.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY.

THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
138 PM EDT SAT SEP 12 2015

DEZ003-004-121815-
DELAWARE BEACHES-INLAND SUSSEX-
138 PM EDT SAT SEP 12 2015

...A STRONG THUNDERSTORM WILL AFFECT SOUTHEASTERN SUSSEX COUNTY...

AT 137 PM EDT...A STRONG THUNDERSTORM WAS NEAR PARSONSBURG...OR 10
MILES EAST OF SALISBURY...MOVING NORTHEAST AT 30 MPH.

WIND GUSTS UP TO 40 MPH ARE POSSIBLE WITH THIS STORM.

LOCATIONS IMPACTED INCLUDE...
MILLSBORO...SELBYVILLE...DAGSBORO...MILLVILLE...GUMBORO...OCEAN
VIEW...FRANKFORD AND SOUTH BETHANY.

FREQUENT CLOUD TO GROUND LIGHTNING IS OCCURRING WITH THIS STORM.
LIGHTNING CAN STRIKE 15 MILES AWAY FROM A THUNDERSTORM. SEEK A SAFE
SHELTER INSIDE A BUILDING OR VEHICLE.

THIS STORM MAY INTENSIFY...SO BE CERTAIN TO MONITOR LOCAL RADIO AND
TV STATIONS...AS WELL AS LOCAL CABLE TV OUTLETS...FOR ADDITIONAL
INFORMATION AND POSSIBLE WARNINGS FROM THE NATIONAL WEATHER SERVICE.

LAT...LON 3846 7551 3871 7529 3861 7516 3859 7518
      3859 7521 3858 7518 3857 7518 3859 7512
      3856 7509 3856 7508 3854 7505 3845 7505
TIME...MOT...LOC 1737Z 240DEG 16KT 3839 7540

JRK