Area Forecast Discussion
Issued by NWS Mt. Holly, NJ

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000
FXUS61 KPHI 200556
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
156 AM EDT WED MAY 20 2015

.SYNOPSIS...
A COLD FRONT FROM SOUTHERN NEW JERSEY TO SOUTHEAST VIRGINIA EARLY
THIS MORNING WILL MOVE OFF THE COASTS BY DAWN. HIGH PRESSURE IS
FORECAST TO FOLLOW TODAY INTO TONIGHT. WEAK LOW PRESSURE IS EXPECTED
TO BE LOCATED OVER NORTH CAROLINA ON THURSDAY BEFORE IT MOVES OUT
TO SEA ON THURSDAY NIGHT. A COLD FRONT FROM THE NORTHWEST IS
ANTICIPATED TO ARRIVE ON FRIDAY EVENING WITH HIGH PRESSURE
FORECAST TO BUILD ACROSS OUR REGION IN ITS WAKE FOR SATURDAY. A
WARM FRONT IS EXPECTED TO APPROACH FROM THE SOUTHWEST ON SUNDAY
AND MONDAY, AS A COLD FRONT PUSHES DOWN FROM THE NORTH AND
NORTHEAST. ANOTHER FRONTAL BOUNDARY MAY MOVE TOWARD OUR REGION
FROM THE NORTHWEST ON TUESDAY.

&&

.NEAR TERM /THROUGH TODAY/...
GUSTY NW WINDS TO 20 MPH FOLLOW A COLD FRONTAL PASSAGE EARLY TODAY
ADVECTING DRIER COOLER AIR SEWD INTO THE REGION WITH RAPIDLY
LOWERING DEWPOINTS. REFRESHING AIR COMING.

TODAY...BRIGHT SUNSHINE WITH AN FEW SC IN THE AFTN. MAX TEMPS
ALMOST 15 DEGREES COOLER THAN THE VALUES OF TUESDAY AND DAYTIME
MAX TEMPS ABOUT 3 TO 5 DEGREES BELOW NORMAL, OCCURRING AROUND 4P!
(FOR CLIMATE PURPOSES...IT APPEARS DUE TO BOUNDARY LAYER MIXING
THAT TODAYS MAX TEMP IN PHL WILL HAVE OCCURRED AT 1AM TODAY-75)

GUSTY NORTHWEST WINDS 20 TO 25 MPH. USED THE WARMER 00Z/20 MAVMOS
GUIDANCE TEMPS AND OTHERWISE 50 50 BLENDED 00Z/20 NAM/GFS MOS
WINDS/DEWS.

CONFIDENCE: WELL ABOVE AVERAGE.

&&

.SHORT TERM /TONIGHT/...
CLEAR TO START WITH RADIATIONAL COOLING HALTED BY RAPIDLY
INCREASING AND LOWERING CIRRUS TO AC AFTER 06Z. NO FROST ANTICIPATED
UNLESS SKIES REMAIN CLEAR THROUGH 09Z AT WALPACK AND PEQUEST IN NW
NJ. THOSE ARE TWO OF THE MOST TYPICALLY COLDER LOW LYING LOCATIONS
IN NJ NJ.

SO 50 50 BLENDED MOS GUIDANCE LEANING TOWARD THE WARMER GFS MOS
TEMPS.

&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...
THE MODEL GUIDANCE IS COMING INTO BETTER AGREEMENT REGARDING
THURSDAY`S WEAK LOW IN NORTH CAROLINA AND ITS IMPACTS ON OUR
WEATHER. IT APPEARS AS THOUGH MID LEVEL CLOUDS WILL BE OVERHEAD
FOR MUCH OF THURSDAY INTO THURSDAY EVENING. A DECK OF
STRATOCUMULUS IS ANTICIPATED TO EXPAND OVER OUR SOUTHERN COUNTIES
ON THURSDAY BEFORE CLEARING GRADUALLY FROM THE NORTHWEST ON
THURSDAY NIGHT. ALSO, RAIN IS ANTICIPATED TO AFFECT NORTHEASTERN
MARYLAND, DELAWARE AND SOUTHERN NEW JERSEY. THE FORECAST IMPACTS
ON THE NORTHERN EDGE OF THE SYSTEM MAY SHIFT A LITTLE AS WE GET
CLOSER TO THE EVENT.

A MID LEVEL SHORT WAVE TROUGH IS FORECAST TO APPROACH FROM THE
WEST ON THURSDAY NIGHT AND IT SHOULD PASS OVERHEAD EARLY ON
FRIDAY. A SECOND SHORT WAVE IS EXPECTED ON FRIDAY NIGHT. IT SHOULD
BE PRECEDED BY A COLD FRONTAL PASSAGE IN OUR REGION ON FRIDAY
EVENING. THE SYSTEM SHOULD NOT HAVE MUCH MOISTURE ASSOCIATED WITH
IT, SO WE WILL FORECAST FEW CLOUDS AND NO RAINFALL.

SURFACE HIGH PRESSURE WILL BUILD INTO OUR REGION ON FRIDAY NIGHT
AND SATURDAY. THE CENTER OF THE HIGH IS EXPECTED TO PASS OFF THE
COAST LATE ON SATURDAY. THE AIR MASS SHOULD BRING OUR FORECAST
AREA DRY WEATHER CONDITIONS ALONG WITH SLIGHTLY BELOW NORMAL
TEMPERATURES.

WARMTH AND MOISTURE WILL LIKELY BE ON THE INCREASE ON THE BACK
SIDE OF THE HIGH AS WE GET INTO SUNDAY AND MONDAY. MEANWHILE, A
BACK DOOR COLD FRONT MAY PUSH DOWN FROM THE NORTH AND NORTHEAST ON
SUNDAY NIGHT AND MONDAY. WE ARE ANTICIPATING AN INCREASE IN CLOUD
COVER FROM THE SOUTHWEST IN THE DEVELOPING ISENTROPIC LIFT. ALSO,
THERE MAY BE SOME STRATUS IN THE WAKE OF THE BACK DOOR COLD FRONT.
THE TIMING AND PROGRESSION OF BOTH BOUNDARIES REMAINS A LOW
CONFIDENCE FORECAST AT THIS POINT, FIVE AND SIX DAYS REMOVED.
HOWEVER, WE WILL INDICATE THE INCREASE IN CLOUD COVER ALONG WITH A
CHANCE OF SHOWERS ON SUNDAY NIGHT AND MONDAY MORNING, AND A CHANCE
OF SHOWERS AND THUNDERSTORMS ON MONDAY AFTERNOON.

THE AXIS OF A MID LEVEL RIDGE IS FORECAST TO PASS OVERHEAD ON
MONDAY NIGHT. ANOTHER FRONTAL BOUNDARY MAY APPROACH FROM THE
NORTHWEST ON TUESDAY, SO WE WILL CONTINUE TO MENTION THE POTENTIAL
FOR SOME CLOUDS AND A CHANCE OF SHOWERS AND AFTERNOON
THUNDERSTORMS.

&&

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

BEFORE 12Z TODAY...NW GUSTS AROUND 20 KT AND GENERALLY CLEAR SKY.

AFTER 12Z TODAY...VFR CLEAR WITH FEW OR SCT SC DURING THE AFTN
AOA 5000 FT. NW WIND GUSTS 20-25 KT.

TONIGHT...VFR CLEAR TO START THEN CIGS AOA 10000 FT ARRIVING
AFTER 06Z. LIGHT NW WIND TURN NNE LATE.

OUTLOOK...
THURSDAY AND THURSDAY NIGHT...MAINLY VFR. A CHANCE OF RAIN FROM
KILG, KMIV AND KACY SOUTHWARD.

FRIDAY THROUGH SUNDAY...MAINLY VFR.

&&

.MARINE...
OVERNIGHT...THE COLD FRONT PASSES WITH A WSHIFT FROM SW TO NW AND
GUSTY AROUND 20 KT. GUSTS COULD REACH 25 KT OVER THE NRN WATERS
AFTER 3 AM. SEAS SHOULD BE NO HIGHER THAN 4 FEET.

TODAY...NORTHWEST WINDS GUSTY TO NEAR 20 KT.

TONIGHT...NORTHWEST WINDS GUSTY 20 KT TURN N-NE AND DIMINISH TO
LESS THAN 15 KT BY THURSDAY MORNING.

OUTLOOK...
THURSDAY THROUGH SUNDAY...NO MARINE HEADLINES ARE ANTICIPATED.

&&

.FIRE WEATHER...
WEDNESDAY...WE`LL SEE WINDS GUSTING TO 25 MPH AND DRY FINE FUELS
ACROSS PORTIONS OF THE REGION, BUT MINIMUM RH`S ARE FORECAST TO BE
IN THE 28-35% RANGE.

ALSO, WIND GUSTS MAY BE AROUND 20 MPH FROM THE NORTHWEST ON FRIDAY
AFTERNOON. RELATIVE HUMIDITY VALUES MAY FALL INTO THE 30 TO 35
PERCENT RANGE AT THAT TIME IN MUCH OF OUR REGION.

&&

.RIP CURRENTS...
SST`S ABOVE NORMAL AND JUST OFF THE COAST SSTS WELL ABOVE NORMAL
BY ALMOST 3C. THIS IS NOT GOOD ONCE IT TURNS HOT AND BEACHES ARE
UNGUARDED. BE SMART ABOUT ANY SWIMMING EARLY THIS SEASON. ATLANTIC
COASTAL WATER TEMPS ARE WARMING --UPPER 50S TO MID 60S.

RIP CURRENT AWARENESS WEEK FOR MT HOLLY IS JUNE 7-13 WITH PSAS
VIA PUBLIC INFORMATION STATEMENTS, SOCIAL MEDIA, NOAA WEATHER
RADIO AND ANY MEDIA INTERVIEWS DESIRED (CONTACT OFFICE).

FOR RIP CURRENTS: DESPITE ANTICIPATED PROJECTIONS OF LOW OR MODERATE
RISK THROUGH THE MEMORIAL DAY WEEKEND, EARLY SEASON FATALITIES
OCCUR WHEN SWIMMING AT UNGUARDED TIMES/LOCATIONS. WEAKER SWIMMERS
OR SWIMMING IN AREAS WHERE RIP CURRENTS ARE STRONGER (JETTIES) CAN
QUICKLY BECOME LIFE THREATENING. WHEN TRAINED LIFEGUARDS ARE NOT
NEARBY, TIMELY RESCUE IS MUCH LESS LIKELY. LETS GET THROUGH THE
MONTH OF MAY WITH ALL SWIMMERS SAFE! SWIM IN THE PRESENCE OF LIFE
GUARDS! THANK YOU.

&&

.CLIMATE...
**TOP 10 WARMEST MAY APPEARS LIKELY IN PTNS OF THE FORECAST AREA**

THE FIRST 19 DAYS OF MAY IN OUR FORECAST AREA ARE AVERAGING WITHIN
ABOUT 1/2 DEGREE OF 7 DEGREES ABOVE NORMAL.

BASED ON THE ENSEMBLE AND FORECAST DETERMINISTICALLY CONSERVATIVE
INCLUDING OUR 330 PM MAY 19 PROJECTIONS THROUGH THE 26TH AND THEN
THE CONSERVATIVE FTPRHA THEREAFTER THROUGH THE 29TH AND NORMAL
TEMPS THE 30TH AND 31ST...OUTLOOKS A TOP 10 WARMEST MAY ON
RECORD. IN ACTUALITY, WE THINK TEMPS WILL BE ABOVE NORMAL THOSE
LAST TWO DAYS OF THE MONTH.

FOR PHILADELPHIA...PERIOD OF RECORD BACK TO 1874. PROJECTING AN
AVG TEMP OF 68.7 OR NEARLY 5 DEGREES ABOVE NORMAL (4.8) AND 3RD
WARMEST ON RECORD. WARMEST WAS 70.8 IN 1991. THEN 69.2 2004.

FOR ALLENTOWN...POR TO 1922. PROJECTING 65.0 OR 5.1 DEGREES ABOVE
NORMAL AND 8TH WARMEST ON RECORD.  WARMEST WAS 67.2 IN 1991.

WE`LL POST SOME INFO ON NORMAL DATE OF FIRST 90 SHORTLY.

&&

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

&&

$$
SYNOPSIS...DRAG/IOVINO
NEAR TERM...DRAG 155
SHORT TERM...DRAG 155
LONG TERM...IOVINO
AVIATION...DRAG/IOVINO/KRUZDLO 155
MARINE...DRAG/IOVINO/KRUZDLO 155
FIRE WEATHER...155
RIP CURRENTS...155
CLIMATE...155



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