Area Forecast Discussion
Issued by NWS Mt. Holly, NJ

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000
FXUS61 KPHI 220750
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
350 AM EDT FRI MAY 22 2015

.SYNOPSIS...
A COLD FRONT WILL CROSS OUR REGION LATER THIS AFTERNOON, THEN HIGH
PRESSURE BUILDS IN SATURDAY BEFORE SHIFTING OFFSHORE SATURDAY NIGHT
AND SUNDAY. A WARM FRONT IS FORECAST TO LIFT NORTH ACROSS OUR AREA
DURING MONDAY. A COLD FRONT IS THEN ANTICIPATED TO REMAIN WELL TO
OUR NORTH AND WEST WEDNESDAY AND THURSDAY AS HIGH PRESSURE REMAINS
ANCHORED IN THE WESTERN ATLANTIC.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
EARLY THIS MORNING...ISOLATED FOG PATCHES.  LEFTOVER CLOUDINESS IS
IN THE PROCESS OF CLEARING. LIGHT WEST-NORTHWEST WIND.

TODAY...SUNNY THIS MORNING THEN PARTLY SUNNY THIS AFTN AS A BAND
OF MODEST INSTABILITY CLOUDINESS AHEAD OF A CFP PASSES SEWD THROUGH
THE AREA WITH DECENT TOTAL TOTALS BUT ALMOST ZERO MLCAPE (PROBABLY
NOT ENOUGH MOISTURE FOR ANYTHING OTHER THAN A POSSIBLE HIGH BASED
SPRINKLE OR .01 SHOWER  WITH GUSTY NORTHWEST WINDS TO 35KT). WE
NOTED SUPPORT FOR THIS IN THE 00Z/22 NSSL WRF AND SPC WRF.  HRRR
DOES NOT HAVE ANYTHING ATTM, SO ITS A CHANCE BUT NOT CATEGORICAL.

INCREASINGLY GUSTY WEST WINDS AHEAD OF THE COLD FRONT WITH 20 MPH
THIS MORNING AND 27-35 MPH BY MID AFTN. THE WSHIFT TO NNW ARRIVES
VCNTY I-80 IN THE 6P-8P TIME FRAME (WHICH IS REALLY THIS EVENING-
EARLY TONIGHT).

TEMPS REBOUND AFTER YDYS 12 TO 18 BELOW NORMAL MAX TEMPS WITH THIS
AFTNS TEMPS ABOUT 15-20 DEGREES WARMER COMPARED TO THURSDAY AFTN
(NEAR NORMAL MAX`S).

FORECAST GENERATED GENERALLY FROM A 5050 BLEND OF 00Z/22 NCEP MOS
GUIDANCE (GFS/NAM).

CONFIDENCE: ABOVE AVERAGE.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SATURDAY/...
CLEAR AND TURNING CHILLY AS THE CFP NEAR I-80 (NE PA/NNJ) IN THE
6P- 8P TIME FRAME SLIPS DOWN TO VCNTY KACY-KPHL AROUND 11P WITH
A PERIOD OF GUSTY NORTH-NORTHWEST WINDS OF 20-25 MPH EXPECTED EARLY
AT NIGHT THEN DECOUPLING-RAPIDLY DIMINISHING WIND LATE AS TEMPS FALL
RAPIDLY.

WILL CONTINUE A TOUCH OF SCT FROST FROM WARREN-SUSSEX COUNTIES IN
NW NJ INTO MONROE AND CARBON COUNTIES OF NE PA. JUST NOT ENOUGH
COVERAGE EXPECTED FOR A FROST ADVY. ALSO WITH FULL GREENUP, PROBABLY
ENOUGH LEAF COVER TO PREVENT MUCH DAMAGE. STILL, CANT BE ABSOLUTELY
SURE AND SO SCT FROST IS IN THE FCST AND POSSIBLE SPS MATERIAL LATER
TODAY FOR THOSE LOCATED IN SUCH PLACES AS WALPACK, PEQUEST, THE
TYPICALLY COLDEST LOW LYING AREAS IN THE NW FRINGE OF OUR FORECAST
AREA.

A BIT OF HIGH THIN CIRRUS POSSIBLE TOWARD SUNRISE SATURDAY?

FCST GENERALLY FROM A 5050 BLEND OF 00Z/22 NCEP MOS GUIDANCE
(GFS/NAM).

CONFIDENCE: ABOVE AVERAGE.

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
THE SYNOPTIC SETUP IS COMPRISED OF A CLOSED LOW MOVING FROM NORTHERN
NEW ENGLAND TO THE CANADIAN MARITIMES SATURDAY. THIS IS DUE TO
ENERGY STARTING TO EJECT INTO THE CENTRAL AND SOUTHERN PLAINS, WHICH
WILL ALSO BUILD A RIDGE FROM FLORIDA NORTHWESTWARD INTO THE MIDWEST
SATURDAY INTO MONDAY. THE RIDGE STRENGTHENS SOME AS IT SHIFTS
EASTWARD MONDAY AND TUESDAY, HOWEVER IT SHOULD THEN START TO FLATTEN
SOME ON ITS NORTHERN SIDE FROM ABOUT TUESDAY ONWARD. THE MAIN
FEATURE IS A FRONTAL BOUNDARY THAT SLIDES ACROSS THE NORTHEAST BUT
THIS THEN LIFTS BACK NORTHWARD AS A WARM FRONT MONDAY. IT LOOKS TO
TURN RATHER WARM TO EVEN HOT NEXT WEEK AS THE UPPER-LEVEL RIDGE IS
IN PLACE DESPITE IT GRADUALLY SHIFTING MORE OFFSHORE WITH TIME. WE
USED A MODEL BLEND FOR SATURDAY THROUGH MONDAY, THEN THE 00Z WPC
GUIDANCE WITH CONTINUITY THEREAFTER. SOME TWEAKS WERE THEN MADE
FOLLOWING ADDITIONAL COLLABORATION WITH OUR NEIGHBORING OFFICES.

FOR SATURDAY...A CHILLY START /PATCHY FROST UP NORTH/, OTHERWISE
HIGH PRESSURE STARTS TO SHIFT OFFSHORE AT NIGHT AS RIDGING BUILDS TO
OUR WEST. THE AIRMASS WILL BE COOL, THEREFORE HIGHS SHOULD BE IN THE
60S TO ABOUT 70 DEGREES ACROSS THE REGION. DUE TO HIGH PRESSURE IN
PLACE, LESS WIND IS EXPECTED COMPARED TO FRIDAY.

FOR SUNDAY AND MONDAY...A RIDGE TO OUR WEST WILL GRADUALLY BUILD
EASTWARD. SOME ENERGY SLIDING SOUTHEASTWARD ACROSS NORTHERN NEW
ENGLAND WILL DROP A FRONTAL BOUNDARY INTO OUR AREA SUNDAY NIGHT.
THIS BOUNDARY GENERALLY LOOKS TO BE ON THE WEAK SIDE, HOWEVER IT
COULD BE ACTIVATED MONDAY AS IT LIFTS NORTHWARD AS A WARM FRONT. AS
THE RIDGE BUILDS, OUR AREA IS STILL WITHIN THE NORTHWESTERLY FLOW
ALOFT. THE LOW-LEVEL FLOW IS FORECAST TO BE SOUTHWESTERLY, AND THE
COMBINATION OF WAA AND SOME FRONTAL LIFT AIDED BY SOME SHORT WAVE
ENERGY ALONG THE FRONT SHOULD PRODUCE SOME CONVECTION ON MONDAY. IT
APPEARS THAT THE BULK OF THE WAA/LIFT IS AIMED UP THE OHIO VALLEY
AND ACROSS THE GREAT LAKES. WE WILL NEED TO WATCH THIS THOUGH AS
SOME CONVECTION COULD SLIP INTO OUR AREA FROM THE WEST/NORTHWEST,
ESPECIALLY THE NORTHERN HALF, DURING MONDAY BEFORE THE RIDGE AXIS
REACHES OUR CWA. THE AMOUNT OF INSTABILITY WILL BE KEY AS WE
CONTINUE TO RECOVER FROM A RATHER DRY AIRMASS THAT IS IN PLACE PRIOR
TO MONDAY. OVERALL, CONVECTION MAY PRODUCE AT LEAST LOCALLY HEAVY
DOWNPOURS MONDAY. A MUCH WARMER AIRMASS IS EXPECTED TO OVERSPREAD
THE AREA ESPECIALLY MONDAY AS AN EXPANDING WARM SECTOR MOVES NORTH,
AND SOME INCREASE IN THE DEW POINTS WILL ALSO OCCUR.

FOR TUESDAY AND WEDNESDAY...WE ARE EXPECTED TO BE IN THE WARM SECTOR
DURING THIS TIME FRAME AS A SHORT WAVE ALOFT AND SURFACE LOW TRACKS
TO OUR NORTH, WHICH WILL FLATTEN THE RIDGE SOME. WHILE THE SURFACE
COLD FRONT IS CURRENTLY FORECAST TO STAY WELL TO OUR NORTH AND WEST,
SOME CONVECTION CANNOT BE RULED OUT. THIS APPEARS TO BE MAINLY
FOCUSED NEAR A LEE SIDE TROUGH IN THE PRESENCE OF A WARM/HOT AND
INCREASINGLY HUMID AIRMASS. GIVEN THE PRESENCE OF THE RIDGE AND THE
NORTHWESTERLY FLOW ALOFT BREAKING DOWN ACROSS OUR AREA, ANY
CONVECTION COULD BE SLOW MOVING WHICH WOULD RESULT IN LOCALLY HEAVY
RAIN. AS OF NOW, THE WESTERN ZONES HAVE A HIGHER CHC OF CONVECTION
GIVEN THE FORECAST PLACEMENT OF THE RIDGE AND ALSO A LEE SIDE
TROUGH. SOME PLACES ARE FORECAST TO REACH 90 DEGREES EACH AFTERNOON.
THE AFTERNOON HEAT INDICES ARE FORECAST TO BE CLOSE TO 95 DEGREES
ESPECIALLY WEDNESDAY AFTERNOON FOR THE URBANIZED AREAS OF THE
PHILADELPHIA METRO. IT SHOULD BE COOLER ALONG THE COAST DUE TO A
SOUTHERLY FLOW.

FOR THURSDAY...IT LOOKS TO BE A REPEAT OF THE PREVIOUS TWO DAYS AS
WE REMAIN IN THE WARM SECTOR, MEANWHILE A COLD FRONT SLOWLY SAGS
SOUTHEASTWARD ACROSS THE GREAT LAKES. SOME OF THE GUIDANCE IS FASTER
WITH THIS FRONT, HOWEVER WE WENT WITH THE WPC TIMING. ONCE AGAIN A
WARM TO EVEN HOT DAY IS ANTICIPATED, ALTHOUGH IT MAY BE A LITTLE
COOLER AS THE RIDGE WEAKENS SOME. SINCE A SOUTHERLY FLOW IS
FORECAST, IT SHOULD BE COOLER ALONG THE COAST. SOME MAINLY AFTERNOON
AND EVENING CONVECTION IS POSSIBLE ESPECIALLY INLAND, PROBABLY
FOCUSED ALONG A LEE SIDE TROUGH.

&&

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

TODAY...MOSTLY VFR PRIOR TO 12Z WITH A LIGHT W-NW WIND. ANY
REMAINING IFR SE NJ SOON DISSIPATES.  THEN AFTER 12Z...VFR CLEAR
BECOMING SCT-BKN AOA 6000 FT THIS AFTN WITH THE SLIGHT CHC OF A WLY
35KT GUSTY SPRINKLE OR LIGHT SHOWER AHEAD OF A COLD FRONT. GENERALLY
GRADIENT WLY GUSTS 20 KT THIS MORNING INCREASE TO 25-30 KT THIS
AFTN.

TONIGHT...VFR CLEAR. THIN CIRRUS POSSIBLE TOWARD SUNRISE SATURDAY.
WSHIFT TO 20-25KT GUSTY NNW THIS EVENING FROM NORTH TO SOUTH, FIRST
NEAR I-80 AROUND 00Z REACHING KPHL/KACY AROUND 03-05Z.

CONFIDENCE: ABOVE AVERAGE.

OUTLOOK...
SATURDAY...VFR. NORTHWEST WINDS AROUND 10 KNOTS, BECOMING WEST-
SOUTHWEST DURING THE AFTERNOON.

SUNDAY...VFR. SOUTHWEST WINDS 10 TO 15 KNOTS, THEN DIMINISHING SOME
AT NIGHT.

MONDAY AND TUESDAY...MAINLY VFR. SOME SHOWERS AND THUNDERSTORMS ARE
POSSIBLE ESPECIALLY DURING MONDAY. SOUTHWEST WINDS MAINLY AROUND
10 KNOTS.

&&

.MARINE...
SAFE BOATING WEEK CONCLUDES TODAY. WE`LL POST OUR FINAL PUBLIC
INFORMATION STATEMENT AROUND 430 AM THIS MORNING WITH THE SOCIAL
MEDIA POST AROUND 8AM. I DID GO AHEAD AND ADD THE NEW USCG SAFETY
APP TO MY SMART PHONE, JUST IN CASE IT COMES IN HANDY VIA
MARINE RELATED TALKS/INTERVIEWS.

THE FORECAST...

SCA VCNTY 44009 EARLY TODAY THOUGH WINDS AND SEAS NOT YET RESPONDING
AS OF 07Z BUT HELD ONTO THE FORECAST BECAUSE WE DONT REALLY KNOW THE
WIND THERE.

OTRW...SCA ALL OTHER WATERS BUT DELAYED SLIGHTLY TO THE PRIMARY
THREAT PERIOD OF 2P-MIDNIGHT. WLY WIND GST 25-30 KT THIS AFTN AHEAD
OF A COLD FRONT THEN JUST AFT OF THE COLD FRONTAL PASSAGE WIND SHIFT
TO NNW THIS EVENING. STRONGEST WIND NEAR THE SHORE WHERE ITS WARMER
AND BETTER MIXING-MOMENTUM TRANSFER.

WINDS DIMINISH TOWARD SUNRISE SATURDAY.

OUTLOOK...
SATURDAY AND SUNDAY...NORTHWEST WINDS DIMINISHING SATURDAY AND THEN
BECOMING SOUTHWEST TOWARD EVENING. THE SOUTHWESTERLY FLOW CONTINUES
SUNDAY AND SHOULD INCREASE SOME, HOWEVER OVERALL THE CONDITIONS
SHOULD BE BELOW ADVISORY CRITERIA.

MONDAY AND TUESDAY...A SOUTHWESTERLY FLOW OF 10-20 KNOTS IS
ANTICIPATED WITHIN A WARM/HOT AIRMASS. THIS MAY RESULT IN THE HIGHER
WINDS CLOSER TO THE COAST. A FEW SHOWERS AND THUNDERSTORMS ARE
POSSIBLE ESPECIALLY MONDAY. SEAS AT OR BELOW 4 FEET, ALTHOUGH THESE
MAY NEAR 5 FEET TUESDAY ACROSS THE NORTHERN COASTAL WATERS.

&&

.FIRE WEATHER...
WIND GUSTS OF 25 TO 30 MPH ARE EXPECTED THIS AFTERNOON AND
RELATIVE HUMIDITY VALUES SHOULD FALL INTO THE 20 TO 30 PERCENT
RANGE IN MUCH OF OUR REGION AT THAT TIME. HOWEVER, YESTERDAYS
RAINFALL IS FORECAST TO KEEP FINE FUEL MOISTURE FROM FALLING BELOW
CRITICAL LEVELS AT THOSE LOCATIONS WHERE THE GREEN-UP IS NOT
COMPLETE, MOST NOTABLY THE PINE BARRENS. AS A RESULT, WE ARE NOT
ANTICIPATING ANY FIRE WEATHER ISSUES FOR FRIDAY.

&&

.RIP CURRENTS...
VERY WARM WEATHER NEXT WEEK WILL GET THE BEACH SEASON GOING.

WATER TEMPS CONTINUE ABOVE NORMAL AND JUST OFF THE COAST THE SSTS
ARE WELL ABOVE NORMAL BY ALMOST 3C. THIS IS NOT GOOD ONCE IT TURNS
HOT AND BEACHES ARE UNGUARDED, SWIMMERS MAY TAKE CHANCES AT
UNGUARDED LOCATIONS. 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 CONTINUES LIKELY IN PORTIONS OF THE FORECAST
 AREA**

THE FIRST 20 DAYS OF MAY IN OUR FORECAST AREA WERE AVERAGING
ABOUT 7 DEGREES ABOVE NORMAL. TEMPERATURE FCSTS FOR NEXT WEEK HAVE
NOT CHANGED SIGNIFICANTLY...SO THE PROJECTIONS FROM YESTERDAY STILL
LOOK ON TRACK.

FOR PHILADELPHIA...PERIOD OF RECORD BACK TO 1874. PROJECTING AN
AVG TEMP OF 68.7 TO 69.3 OR AROUND 5 DEGREES ABOVE NORMAL AND AT
THE LEAST, 3RD WARMEST ON RECORD. WARMEST WAS 70.8 IN 1991. THEN
69.2 2004.

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

POSTED BECAUSE ITS POSSIBLE THAT WE MAY HAVE OUR FIRST 90 IN
PHILADELPHIA BY THE MIDDLE OF NEXT WEEK.

NORMAL FIRST DATE OF 90 OR HIGHER.

PHILADELPHIA MAY 29
ALLENTOWN MAY 30
WILMINGTON JUNE 4
ATLANTIC CITY JUNE 11.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY FROM NOON TODAY TO 6 AM EDT SATURDAY FOR
     ANZ450>453.
     SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR ANZ454-
     455.
     SMALL CRAFT ADVISORY FROM NOON TODAY TO MIDNIGHT EDT TONIGHT
     FOR ANZ430-431.

&&

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


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