NWS Philadelphia/Mount Holly wrote its last area forecast discussion before the first event at Sep 28, 3:37 AM EST, 7 hours 53 minutes earlier.
Area forecast discussion, Sep 28, 3:37 AM EST, 7 hours 53 minutes before
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
437 AM EDT SUN SEP 28 2008
.SYNOPSIS...
THE REMNANTS OF THE SOUTHEASTERN U.S. LOW PRESSURE SYSTEM WILL LIFT
THROUGH OUR REGION TODAY. MEANWHILE, TROPICAL CYCLONE KYLE WILL
MOVE NORTH AND PASS WELL TO THE EAST OF DELAWARE AND NEW JERSEY
EARLY THIS MORNING. TONIGHT, AFTER THE REMNANT LOW AND KYLE MOVE
AWAY TO OUR NORTHEAST, A WEAK COLD FRONT WILL WILL PASS THROUGH OUR
REGION. WEAK HIGH PRESSURE SHOULD FOLLOW FOR MONDAY INTO TUESDAY. A
COLD FRONT FROM THE NORTHWEST IS ANTICIPATED TO ARRIVE EARLY ON
WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WATER VAPOR IMAGERY SHOWS, QUITE CLEARLY, THE REMAINS OF THE
SOUTHEASTERN LOW PRESSURE SYSTEM ADVANCING TOWARD US. MODELS ARE
IN GOOD AGREEMENT REGARDING H7 TO H5 Q-VECTOR CONVERGENCE AND H5
VORTICITY ADVECTION INTO OUR AREA TODAY. LOWER LEVEL FRONTOGENESIS
IS NOT TOO IMPRESSIVE, AND ONCE THE RELATIVELY GENTLE WINDS SHIFT
TO OFFSHORE WE LOSE ANY LOW LEVEL THETA-E ADVECTION. STILL, THERE
IS DECENT MOISTURE AVAILABLE EVEN THOUGH WE LOSE THE LOWER LEVEL
FLOW FROM THE SOUTHEAST. H8 DEW POINTS, AGAIN, ARE AT OR ABOVE 10
DEG C. SOUNDINGS HAVE A BIT OF CAPE, ALTHOUGH THEY ARE PRETTY
CLOSE TO MOIST ADIABATIC.
MAV AND MET STAT GUIDANCE ARE GIVING POPS THAT ARE UNIFORMLY IN THE
CATEGORICAL RANGE OVER THE NORTHWESTERN PART OF THE AREA AND
UNIFORMLY IN THE LIKELY RANGE OVER THE SOUTHEASTERN PART. WERE NOT
GOING TO QUIBBLE. WE GO CATEGORICAL NORTHWEST AND LIKELY SOUTHEAST,
AND WE MAINTAIN THE SLIGHT CHANCE OF THUNDER. QPF VALUES OFF THE
ECMWF ARE NOT OMINOUS. WE DO STILL HAVE THE POTENTIAL FOR LOCALLY
HEAVY DOWNPOURS, ESPECIALLY WITH THESE SOUNDINGS, BUT WELL
CONFINE THAT TO A MENTION IN THE HWO.
REGARDING FOG, THE SHOWERS THAT HAVE BEEN LIFTING THROUGH THE REGION
HAVE BEEN MIXING THINGS UP A BIT, BUT THERE STILL ARE SITES
AROUND THE AREA THAT HAVE VISIBILITIES AT OR BELOW ONE MILE AS OF
08Z. WE MAINTAIN THE MENTION OF FOG IN THE MORNING PART OF TODAYS
FORECAST. WE ARE MONITORING TO SEE IF ANYTHING ELSE IS REQUIRED.
WE START THE MORNING WITH WARM TEMPERATURES, AND CONTINUITY WOULD
HAVE US LEAN TOWARD WARMER STAT GUIDANCE. BASICALLY, THATS WHAT
WEVE DONE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
THE EXITING SYSTEM INCLUDES A WEAK, TRAILING COLD FRONT, AND THE
MODELS ARE RATHER SLOW TO CLEAR US OUT. WE CARRY CHANCE POPS FOR
THE FIRST PART OF TONIGHT AND SLIGHT CHANCE POPS FOR THE LATTER
PART. WE ONLY SLOWLY BEGIN TO BREAK THE CLOUDINESS. WE NOTE THAT,
IN ADDITION TO LINGERING CLOUDS, THERE IS NOT A LOT OF COLD AIR
ADVECTION BEHIND THIS FRONT. GUIDANCE AND CONTINUITY WERE VERY
CLOSE, BUT WHERE THEY STARTED TO SHOW A BID OF A SPREAD TOWARD
WARMER TEMPS, MAINLY MOVING SOUTHEAST THROUGH THE REGION, WE
NUDGED TEMPS UP JUST A LITTLE BIT.
OUR FORECAST FOR MONDAY IS ON THE OPTIMISTIC SIDE. THE ECMWF WANTS A
LITTLE BIT OF LINGERING MORNING RAINFALL, BUT FOR NOW WE ARE GOING
DRY WITH A SLOW CLEARING TREND. TEMPERATURES LOOK TO BE A BIT ABOVE
NORMAL FOR LATE SEPTEMBER. THERE MAY BE SUFFICIENTLY CLEAR SKIES AND
LIGHT WINDS MONDAY NIGHT FOR SOME RADIATING, AND WE SUGGESTED THIS
IN OUR FORECAST WITHOUT HITTING THE IDEA TOO HARD. THERE IS A
POSSIBILITY THAT HIGH CLOUDS IN ADVANCE OF THE NEXT SYSTEM WILL BE
MOVING IN.
A SHARPENING MID LEVEL VORTEX APPROACHES ON TUESDAY, AND WE KEPT THE
CHANCE POPS FOR THE NORTHWEST AND SLIGHT CHANCE POPS FOR THE REST OF
THE AREA. WE SPLIT THE DIFFERENCE ON GUIDANCE TEMPS, BECAUSE WERE
UNCERTAIN ABOUT THE PRECISE TIMING OF THE CLOUDS, THE PRECIPITATION,
AND THE STRENGTH OF WARM AIR ADVECTION AHEAD OF THE APPROACHING
SYSTEM.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AS THE LONG WAVE TROUGH CONTINUES TO DEVELOP OVER THE EASTERN STATES
AT MID WEEK, A SURFACE COLD FRONT IS FORECAST TO PASS THROUGH OUR
REGION EARLY ON WEDNESDAY. AS A RESULT, WE HAVE MENTIONED A CHANCE
OF SHOWERS FOR TUESDAY NIGHT INTO WEDNESDAY.
WITH THE TROUGH, WE ARE EXPECTING AT LEAST PARTLY CLOUDY SKIES FOR
WEDNESDAY NIGHT INTO THURSDAY, WITH A FAIR AMOUNT OF CUMULUS AND
STRATOCUMULUS OVERHEAD.
A SECOND COLD FRONT IS EXPECTED TO ARRIVE EARLY ON FRIDAY, USHERING
IN A COOL AUTUMNAL AREA OF HIGH PRESSURE FOR NEXT WEEKEND. IT
APPEARS AS THOUGH WE MAY SEE A FAIR AMOUNT OF FROST AT THAT TIME,
ESPECIALLY ACROSS OUR NORTHERN COUNTIES.
&&
.AVIATION /14Z SUNDAY THROUGH THURSDAY/...
THE LOW CLOUDS AND SHOWERS ARE MAKING THIS MORNING A TOUGH ONE FOR
VFR FLYING. TOPS OF THE LOWER DECKS IS 10,000 FT WITH SOME CI UP
AROUND 18,000 FT. THE SOURCE FOR THE IFR WEATHER IS THE ONSHORE
FLOW...NOT STRONG BY ANY STANDARDS...BUT PERSISTENT AND CHOCK FULL
OF MOISTURE. THE GREATEST CONCENTRATION OF SHOWERS IS NORTH OF PHL
TO ABE AND WEST TO RDG. ECHOES MAY NOT LOOK HEAVY BUT ABE IS REPORT
+R AT THIS TIME. TYPICAL IN WARM TOP CONVECTION. SAW ONE POSITIVE
LIGHTNING STRIKE NEAR WEST END OF RARITAN BAY.
MURKY, DAMP WEATHER WAS AFFECTING THE TAF SITES, AND IS FORECAST TO
CONTINUE TO DO SO TODAY. A QUASI-WARM FRONT SEEMED TO BE MOVING
THROUGH THE AREA DURING THE OVERNIGHT PERIOD, AS A SOUTHEASTWARD-
CURVING BAND OF SHOWERS AND ISOLATED THUNDERSTORMS WAS MOVING
NORTHWARD THROUGH MUCH OF THE AREA. ANTICIPATING SEVERAL AMENDMENTSS FOR
EACH SITE.
OUTLOOK...
DRY WEATHER IS FORECAST TO RETURN MONDAY, WITH ANOTHER CHANCE FOR
SHOWERS FROM LATE TUESDAY INTO WEDNESDAY. COOLER WEATHER SHOULD
BEGIN TO ADVECT INTO THE REGION WEDNESDAY.
&&
.MARINE...
WINDS SHOULD NOT BE A CONCERN TODAY, AS THE GRADIENT HAS RELAXED
FROM A COUPLE OF DAYS AGO. HOWEVER, WITH THE PERSISTENT ONSHORE
FLOW, AND THE PASSAGE OF HURRICANE KYLE TO OUR EAST TODAY, SEAS
REMAIN ROILED, ALTHOUGH NOT AS HIGH AS PREVIOUS DAYS. WAVEWATCH
SEEMS TO BE A BIT OVERDONE, AND HAS INITIALIZED TOO HIGH. WINDS WILL
SWITCH FROM ONSHORE TO OFFSHORE THIS MORNING, AND THIS WILL
EVENTUALLY SUPPRESS SEAS AS TIME GOES ON. BUT, WITH THE SWELLS FROM
KYLE, SEAS ARE FORECAST TO REMAIN IN THE 5 TO 9 FOOT RANGE TODAY,
SUBSIDING A BIT TONIGHT, AND THEN DROPPING FURTHER TO 3 TO 5 FEET
MONDAY MORNING BEFORE DROPPING BELOW 5 FEET MONDAY AFTERNOON. WITH
THIS IN MIND, THE SMALL CRAFT ADVISORY WILL BE CHANGED TO A SMALL
CRAFT ADVISORY FOR HAZARDOUS SEAS, AND EXTENDED THROUGH MONDAY
MORNING.
WAVES AT OCEAN GROVE ON THE BEACH ARE 3.5 FEET...NEAR 5.5 FEET OFF
LONG BEACH ISLAND AND 4.0 FEET AT AVALON. WAVE DIRECTION IS AT A 90
ANGLE TO THE BEACH. WAVES AT BETHANY BEACH DELAWARE ARE 3 FEET.
BEYOND MONDAY, THE PRESSURE PATTERN IS RATHER FLAT MONDAY NIGHT INTO
TUESDAY. LOW PRESSURE MOVES FROM PENNSYLVANIA TO THE COAST TUESDAY
NIGHT INTO EARLY WEDNESDAY, AND THERE IS SOME COLD AIR ADVECTION
BEHIND IT WITH STRONGER WINDS INTO WEDNESDAY IN THE OFFSHORE FLOW.
.RIP CURRENTS...
OUR IN-HOUSE PROGRAM FOR COMPUTING THE RIP CURRENT RISK ALONG THE
NEW JERSEY AND DELAWARE COASTLINE SHOWS THE HIGH END OF MODERATE FOR
TODAY. HOWEVER, WITH RESIDUAL EFFECTS FROM THE STRONG ONSHORE FLOW
36 TO 60 HOURS AGO, WITH HURRICANE KYLE MOVING EAST OF OUR AREA
TODAY, AND WITH THE NEW MOON MONDAY, IT WAS DECIDED TO RAISE THE RIP
CURRENT RISK ONE CATEGORY TODAY, TO HIGH. ALSO AIDING THIS DECISION
WAS THE FACT THAT THIS IS A SUNDAY AND THERE WILL PROBABLY BE SOME
PEOPLE AT THE BEACHES, EVEN IN SPITE OF THE MURKY WEATHER. AFTER
TODAY, THE THREAT IS EXPECTED TO DROP TO MODERATE. THAT SHOULD DO
IT FOR THE RIP CURRENT SEASON, WHICH ENDS THE LAST DAY OF SEPTEMBER
AND RESUMES AGAIN AROUND MEMORIAL DAY 2009. REMEMBER...THE WATER
TEMPERATURES ARE STILL WARM AND YOU MIGHT WANT TO TAKE THAT LAST DIP
IN THE OCEAN, BUT REFRAIN FROM ENTERING THE OCEAN AT NIGHT, ALONE OR
ON UNGUARDED BEACHES.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 10 AM EDT MONDAY
FOR ANZ450>455.
&&
SYNOPSIS...DELISI/IOVINO/NIERENBERG
NEAR TERM...DELISI
SHORT TERM...DELISI
LONG TERM...IOVINO
AVIATION.../EBERWINE
MARINE.../EBERWINE