NWS Philadelphia/Mount Holly wrote its last area forecast discussion before the first event at Nov 2, 6:18 AM EST, 42 minutes earlier.
Area forecast discussion, Nov 2, 6:18 AM EST, 42 minutes before
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
618 AM EST SUN NOV 2 2014
.SYNOPSIS...
STRONG LOW PRESSURE WILL CONTINUE TO MOVE INTO THE CANADIAN
MARITIMES THROUGH TONIGHT. HIGH PRESSURE WILL BUILD TO OUR SOUTH
MONDAY INTO EARLY TUESDAY, BEFORE MOVING OFFSHORE TUESDAY NIGHT
AHEAD OF THE NEXT FRONTAL BOUNDARY EXPECTED EARLY WEDNESDAY. AN AREA
OF LOW PRESSURE MAY DEVELOP ALONG THIS BOUNDARY TO OUR SOUTHWEST,
THEN COMBINE WITH ANOTHER LOW MOVING IN FROM THE MIDWEST AND CREATE
ANOTHER COASTAL STORM THURSDAY NIGHT INTO FRIDAY. HIGH PRESSURE IS
THEN EXPECTED TO BUILD TO OUR SOUTH SATURDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE BIG STORY TODAY WILL BE THE WINDS. FIRST THIS MORNING, THERE
IS A THREAT THAT STRONGER WINDS FROM A LOW LEVEL JET COULD MIX
DOWN SHORTLY AFTER SUNRISE UNTIL THE JET DIMINISHES BY ABOUT 15Z.
KDIX DERIVED WINDS CURRENTLY SHOW WINDS AROUND 50KT ABOUT 3000 FT
AGL. HOWEVER, FOR NOW HAVE CHOSEN NOT TO ISSUE A WIND ADVISORY AS
CLOUD COVER WILL BE SLOW TO ERODE WHICH WILL HINDER ANY MORNING
MIXING.
WHILE A TIGHT PRESSURE GRADIENT WILL MEAN WINDY CONDITIONS WILL
CONTINUE THROUGH THE DAY, THE OTHER PERIOD WHICH WILL BE WATCHED
CLOSELY FOR APPROACHING WIND ADVISORY CONDITIONS WILL BE FROM 21Z
THROUGH SUNSET THE HEIGHT GRADIENT IN THE MID AND UPPER LEVELS
INCREASES. THROUGH THIS PERIOD MODEL SOUNDINGS SHOW A NEARLY DRY
ADIABATIC LAPSE RATE THROUGH 850 MB SUGGESTING DEEPER MIXING.
HOWEVER, THE LARGEST HEIGHT GRADIENTS ARE NOT EXPECTED UNTIL AFTER
SUNSET AND THE PRESSURE GRADIENT WILL BE A BIT MORE RELAXED AFTER
18Z. THUS, DO NOT HAVE ENOUGH CONFIDENCE TO ISSUE A WIND ADVISORY FOR
THIS PERIOD EITHER.
AMPLE COLD AIR ADVECTION WILL CONTINUE TODAY. THUS, EXPECT HIGHS
GENERALLY LOWER THAN YESTERDAY AND 10 TO 15 DEGREES BELOW NORMALS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/...
AS MENTIONED PREVIOUSLY, THE LARGEST MID AND UPPER LEVEL HEIGHT
GRADIENTS ARE EXPECTED TO BE OVER THE REGION AFTER SUNSET THIS
EVENING, BUT WITH A NOCTURNAL INVERSION, DO NOT EXPECT WIND ADVISORY
CONDITIONS. INSTEAD, EXPECT THE BIG STORY TONIGHT TO BE TEMPERATURES
WITH ALL OF THE REGION NEAR OR BELOW FREEZING, AND MUCH OF THE
REGION LIKELY TO BOTTOM OUT IN THE 20S. SINCE GROWING SEASON HAS
ENDED HOWEVER, NO FREEZE WARNINGS WILL BE ISSUED.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
ON MONDAY AND MONDAY NIGHT, HIGH PRESSURE WILL BUILD TO OUR SOUTH
AND NOSE ITS WAY NORTHWARD ACROSS OUR AREA. WITH LITTLE MOISTURE TO
WORK WITH AS EVIDENT FROM PW VALUES 0.5 INCHES OR LESS, AND NO
STRONG SHORT WAVE/VORTICITY IMPULSES IN THE NORTHWEST FLOW ALOFT, NO
PRECIPITATION IS EXPECTED THROUGH MONDAY NIGHT. THERE MAY BE AN
INCREASE IN CLOUDS LATE MONDAY INTO MONDAY NIGHT AS SOME MID-LEVEL
MOISTURE SLIDES ACROSS THE AREA, OTHERWISE, DRY WEATHER WILL PREVAIL
THROUGH MONDAY NIGHT.
ON TUESDAY, THE HIGH PUSHES OFF THE SOUTHEAST COAST, SETTING UP A
RETURN FLOW ACROSS THE AREA WHICH WILL ALLOW TEMPERATURES TO WARM
AND AN INCREASE IN SURFACE DEWPOINTS. WE DO NOT EXPECT ANY
PRECIPITATION THROUGH THE DAY TUESDAY AS PW VALUES REMAIN LOW AND
STILL NO STRONG SHORT WAVE/VORTICITY IMPULSES ARE EXPECTED IN THE
DEVELOPING SOUTHWEST FLOW ALOFT. AN INCREASE IN CLOUD COVER IS
LIKELY, MAINLY LATER IN THE DAY TUESDAY.
AS WE MOVE INTO TUESDAY NIGHT AND EARLY WEDNESDAY, A COLD FRONT IS
EXPECTED TO APPROACH FROM THE WEST. MODELS ARE SHOWING THE
PRECIPITATION DRYING OUT/DISSIPATING BEFORE IT REACHES OUR AREA,
HOWEVER, THERE IS A SMALL CHANCE SOME ISOLATED/SCATTERED SHOWERS MAY
MOVE INTO MOSTLY OUR NORTHWESTERN AREAS.
THEN THINGS GET INTERESTING AGAIN. MEDIUM RANGE MODELS ARE NOW
SLOWING DOWN THE FRONTAL BOUNDARY AS IT SAGS INTO OUR AREA
WEDNESDAY, THEN DEVELOP AN AREA OF LOW PRESSURE TO OUR SOUTHWEST
WEDNESDAY NIGHT ALONG THIS BOUNDARY. MEANWHILE, THEY MOVE ANOTHER
LOW THROUGH THE MIDWEST TOWARD OUR AREA, BEFORE IT MERGES WITH THE
AFOREMENTIONED LOW ALONG THE BOUNDARY INTO A STRONG COASTAL LOW
THURSDAY NIGHT INTO FRIDAY. THERE'S GOOD AGREEMENT IN THIS
OCCURRING, ALTHOUGH THERE IS SLIGHT TIMING AND PLACEMENT
DIFFERENCES. THIS WOULD LEAD TO ANOTHER PERIOD OF HEAVY RAIN
POTENTIAL, STRONG WINDS, AND COASTAL FLOODING. THIS WILL NEED TO
BE WATCHED CLOSELY OVER THE NEXT FEW DAYS.
THE LOW IS FORECAST TO CONTINUE TO LIFT TO OUR NORTH FRIDAY NIGHT
INTO SATURDAY. A SHARP DROP IN TEMPERATURES WILL LIKELY OCCUR AGAIN
BEHIND THIS SYSTEM, AND DEPENDING ON HOW FAST THE LOW LIFTS TO THE
NORTH, THERE COULD BE A PERIOD OF RAIN CHANGING OVER TO SNOW FOR OUR
HIGHER ELEVATIONS LATER ON FRIDAY INTO FRIDAY EVENING.
SATURDAY IS EXPECTED TO BE PRECIPITATION FREE AS PW VALUES DROP
BEHIND THE DEPARTING LOW, BUT WINDS WILL LIKELY REMAIN GUSTY THROUGH
THE DAY.
&&
.AVIATION /11Z SUNDAY THROUGH THURSDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
FOR THE 12Z TAFS...VFR CONDITIONS WILL CONTINUE ACROSS THE REGION
THROUGH THE TAF PERIOD. NORTHWESTERLY WINDS UP TO 25G35KT ARE
EXPECTED ACROSS THE REGION TODAY. A FEW GUSTS TO 40KT CAN NOT BE
RULED OUT ESPECIALLY BETWEEN 12 AND 15Z AND AGAIN BETWEEN 21 AND
00Z. WINDS WILL BE SLOW TO DIMINISH AFTER 00Z, BUT SHOULD SETTLE
IN TO 10G20KT FOR MUCH OF THE OVERNIGHT HOURS.
OUTLOOK...
MONDAY-TUESDAY NIGHT ...VFR. WEST-NORTHWEST WIND GUSTS 15-20 KNOTS
MONDAY AFTERNOON. WINDS DIMINISH AFTER SUNSET MONDAY.
WEDNESDAY-WEDNESDAY NIGHT...VFR THROUGH THE DAY WITH INCREASING
CLOUDS AND POSSIBLE SHOWERS OVERNIGHT WHICH MAY LEAD TO MVFR
CONDITIONS OVERNIGHT.
THURSDAY...DIMINISHING CONDITIONS WITH MVFR OR LOWER POSSIBLE, WITH
PERIODS OF RAIN AND WINDY CONDITIONS ALSO POSSIBLE.
&&
.MARINE...
GALE CONDITIONS ARE EXPECTED TO CONTINUE THROUGH THIS EVENING AT
LEAST. A FEW GALE GUSTS MAY OCCUR ON THE OCEAN WATERS AFTER
MIDNIGHT, BUT WILL NOT EXTEND THE GALE WARNING AT THIS TIME UNTIL WE
SEE HOW THE WINDS TODAY EVOLVE. EVEN AFTER WINDS DROP BELOW GALE
CONDITIONS, BOTH WINDS AND SEAS ARE EXPECTED TO REMAIN IN SMALL
CRAFT ADVISORY CONDITIONS FOR MUCH OF THE OVERNIGHT HOURS.
OUTLOOK...
MONDAY-MONDAY NIGHT...SMALL CRAFT ADVISORY LEVELS EARLY, THEN
DROPPING BELOW ADVISORY LEVELS DURING THE DAY.
TUESDAY-WEDNESDAY NIGHT...SUB SMALL CRAFT ADVISORY LEVEL CONDITIONS
EXPECTED, ALTHOUGH WINDS MAY GUST NEAR 20 KNOTS AT TIMES.
THURSDAY...INCREASING LIKELIHOOD OF AT LEAST SMALL CRAFT ADVISORY
CONDITIONS AS LOW PRESSURE DEVELOPS TO OUR SOUTHWEST.
&&
.TIDES/COASTAL FLOODING...
MINOR COASTAL FLOODING IS ONGOING ALONG THE ATLANTIC COASTAL
REGIONS. HIGH TIDE HAS ALREADY OCCURRED, HOWEVER WATER LEVELS WILL
BE SLOW TO FALL ESPECIALLY IN THE BACK BAYS, SO WILL CONTINUE THE
COASTAL FLOOD ADVISORY THROUGH 13Z. WITH THE SHIFT TO MORE OFF
SHORE FLOW, EXPECT THE THREAT FOR COASTAL FLOODING TO GREATLY
DECREASE BY THE NEXT HIGH TIDE CYCLE.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...COASTAL FLOOD ADVISORY UNTIL 8 AM EST THIS MORNING FOR NJZ020-
022>027.
DE...COASTAL FLOOD ADVISORY UNTIL 8 AM EST THIS MORNING FOR DEZ003-
004.
MD...NONE.
MARINE...GALE WARNING UNTIL MIDNIGHT EST TONIGHT FOR ANZ430-431-450>455.
&&
SYNOPSIS...ROBERTSON
NEAR TERM...JOHNSON
SHORT TERM...JOHNSON
LONG TERM...ROBERTSON
AVIATION...JOHNSON/ROBERTSON
MARINE...JOHNSON/ROBERTSON
TIDES/COASTAL FLOODING...JOHNSON