108
FXUS61 KPHI 130939
AFDPHI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
439 AM EST WED NOV 13 2024
SYNOPSIS
HIGH PRESSURE REMAINS IN CONTROL THROUGH THURSDAY. A WEAK AREA OF
LOW PRESSURE APPROACHES ON THURSDAY NIGHT, WITH A COASTAL LOW
DEVELOPING WELL TO THE SOUTH. THE COASTAL LOW PUSHES OFF THE MID-
ATLANTIC COAST ON FRIDAY WITH HIGH PRESSURE BUILDING IN FOR THE
WEEKEND. ANOTHER FRONTAL SYSTEM APPROACHES TO START NEXT WEEK BEFORE
HIGH PRESSURE MOVES BACK IN FOR THE MIDDLE OF NEXT WEEK.
NEAR TERM /THROUGH TONIGHT/
THROUGH THE NEAR TERM, SHORT WAVE RIDGING WILL BE THE DOMINANT
FEATURE LEADING TO DRY AND CALM CONDITIONS. SEE THE FIRE WEATHER
SECTION BELOW ABOUT IMPLICATIONS FOR FIRE SPREAD. OTHERWISE, THE
OTHER BIG STORY OF THIS PERIOD WILL BE LOW TEMPERATURES TONIGHT
WHICH OUTSIDE OF THE URBAN CORRIDOR AND IMMEDIATE COAST COULD BE THE
LOWEST TEMPERATURES WE HAVE SEEN SO FAR THIS FALL. THE CALM WINDS,
DRY AIR, AND CLEAR SKIES WILL LEAD TO EFFICIENT RADIATIONAL COOLING,
ESPECIALLY IN THE PINE BARRENS, RIVER VALLEYS, AND INTERIOR
DELMARVA.
SHORT TERM /THURSDAY THROUGH FRIDAY/
A DECAYING TROUGH MOVES THROUGH THE CENTRAL US, WITH AN ASSOCIATED
AREA OF LOW PRESSURE MOVING TOWARDS THE GREAT LAKES. THIS SURFACE
LOW WILL TRANSFER ITS ENERGY TO A SECONDARY LOW DEVELOPING OVER
EASTERN NORTH CAROLINA. THIS SECONDARY LOW WILL PUSH SOUTHEAST OFF
THE MID-ATLANTIC COAST. GUIDANCE HAS TRENDED DRIER OVERALL AS THE
SECONDARY SURFACE LOW LOOKS TO DEVELOP FURTHER SOUTH THAN PREVIOUSLY
THOUGHT, WITH STRONG HIGH PRESSURE PASSING TO THE NORTH HAVING MORE
INFLUENCE. THE RESULT WILL BE A MAINLY DRY THURSDAY WITH INCREASING
CLOUDS AS THE SYSTEM APPROACHES. HIGHS WILL BE IN THE UPPER 40S/LOW
50S.
SOME SHOWERS ARE POSSIBLE THURSDAY NIGHT, ESPECIALLY SOUTH OF
PHILADELPHIA. RAINFALL AMOUNTS WERE BASICALLY CUT IN HALF WITH THIS
UPDATE. THE HIGHEST AMOUNTS WILL BE OVER LOWER DELMARVA, THOUGH ONLY
UP TO A QUARTER OF AN INCH AT MOST. MOST AREAS NORTH OF THE
PHILADELPHIA METRO AREA WILL EITHER SEE A FEW DROPS OR NOTHING AT
ALL. IF PRECIPITATION WERE TO MAKE IT FAR ENOUGH NORTH TO REACH THE
HIGHER ELEVATIONS, A FEW SNOWFLAKES CAN'T BE RULED OUT. OVERALL, NOT
AN OVERLY IMPACTFUL EVENT AND NOTHING TO PUT A DENT IN OUR CURRENT
DROUGHT. LOWS ON THURSDAY NIGHT WILL RANGE FROM THE LOW TO MID 30S
NORTH AND WEST OF THE I-95 CORRIDOR TO UPPER 30S/LOW 40S ALONG AND
SOUTH OF I-95.
EXPECT IMPROVING CONDITIONS ON FRIDAY AS SKIES CLEAR OUT WITH
SURFACE LOW PUSHING OFFSHORE AND HIGH PRESSURE MOVING IN. ANY
LINGERING SHOWERS OVER SOUTHERN DELAWARE MOVE OUT BY THE LATE
MORNING WITH SOME SUN EXPECTED FOR THE AFTERNOON. TEMPERATURES WILL
GENERALLY BE IN THE MID 50S.
LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/
UPPER LEVEL RIDGING BUILDS IN FOR THE WEEKEND WITH AN EXPANSIVE AREA
OF HIGH PRESSURE MOVING IN FROM THE WEST. THIS WILL RESULT IN A DRY
WEEKEND WITH MODERATING TEMPERATURES. HIGHS WILL GET INTO THE 60S
WITH A STEADY NORTHWEST FLOW. OVERNIGHT LOWS FRIDAY AND SATURDAY
NIGHT WILL BE IN THE MID TO UPPER 30S. THE RETURN OF DRY NORTHWEST
FLOW WILL BRING ANOTHER PERIOD FOR POTENTIAL FIRE WEATHER
CONDITIONS, ESPECIALLY ON SATURDAY, WHERE WIND GUSTS BETWEEN 20-30
MPH ARE POSSIBLE WITH A TIGHT GRADIENT IN PLACE DUE TO THE INCOMING
HIGH AND AN AREA OF LOW PRESSURE NEAR THE CANADIAN MARITIMES. WINDS
WILL BE LOWER ON SUNDAY WITH HIGH MOVING CLOSER AND THE GRADIENT
WEAKENING BUT RHS WILL BE SIMILAR TO SATURDAY (BETWEEN 25-35% DURING
THE AFTERNOON).
THE RIDGE BREAKS DOWN ON MONDAY WITH A SHORTWAVE IMPINGING IN FROM
CANADA. AT THE SURFACE, A COLD FRONT LOOKS TO COME THROUGH BUT THE
FRONT LOOKS MOISTURE STARVED AT THE MOMENT. RIDGING AT THE SURFACE
AND ALOFT WILL BUILD IN FOR THE MIDDLE OF THE NEXT WEEK AS THE LONG
TERM PERIOD LOOKS RATHER DRY. THE FRONT DOESN'T LOOK TO LOWER
TEMPERATURES MUCH, AND ABOVE NORMAL TEMPERATURES SHOULD CONTINUE
INTO THE MIDDLE OF NEXT WEEK.
AVIATION /10Z WEDNESDAY THROUGH SUNDAY/
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
THROUGH TODAY...VFR WITH ONLY FEW HIGH CLOUDS BUILDING IN LATE
TODAY. WINDS STARTING NNE, BUT BECOMING MORE NE. WIND SPEEDS SHOULD
GENERALLY BE AT OR BELOW 10 KT.
TONIGHT...VFR WITH INCREASING HIGH CLOUDS. NE WINDS 5 KT OR LESS.
OUTLOOK...
THURSDAY...VFR. NO SIGNIFICANT WEATHER EXPECTED.
THURSDAY NIGHT...PRIMARILY VFR THOUGH SOME MVFR CEILINGS POSSIBLE AS
SCATTERED SHOWERS MOVE IN. HIGHEST CHANCE FOR SHOWERS EXPECTED FROM
KPHL ON SOUTH.
FRIDAY THROUGH SUNDAY...VFR. GUSTY NORTHWEST WINDS POSSIBLE ON
SATURDAY WITH GUSTS UP TO 25 KT ANTICIPATED.
MARINE
SMALL CRAFT ADVISORY REMAINS IN EFFECT FOR THE ENTIRE MARINE AREA.
WINDS SHOULD CONTINUE TO GRADUALLY DIMINISH. BY SUNRISE, WINDS
SHOULD BE BELOW SCA CRITERIA FOR MANY AREAS WITH THE EXCEPTION OF
AREAS 10 TO 20 NMI OFF SHORE GENERALLY SOUTH OF MANASQUAN INLET.
EVEN IN THESE AREAS, WINDS SHOULD DROP BELOW 25 KT BY MID DAY.
THEN THE MAIN CONCERN IS ELEVATED SEAS, ESPECIALLY FOR AREAS SOUTH
OF THE MANASQUAN INLET. BASED ON THE LATEST GUIDANCE IT APPEARS AS
IF SEAS WILL REMAIN NEAR OR ABOVE 5 FEET THROUGH THE NIGHT AND INTO
THURSDAY.
FOR THE DELAWARE BAY AND THE COASTAL WATERS FROM SANDY HOOK TO
MANASQUAN INLET, EXPECT WINDS AND WAVES TO BE BELOW SCA CRITERIA
ONCE WINDS DROP BELOW 25 KT LATER THIS MORNING.
OUTLOOK...
THURSDAY THROUGH THURSDAY NIGHT...THE SMALL CRAFT ADVISORY WAS
EXTENDED FOR COASTAL WATERS SOUTH OF MANASQUAN INLET AS SEAS WILL BE
AROUND 5 FEET. NORTH OF MANASQUAN INLET AND ON DELAWARE BAY, NO
MARINE HEADLINES EXPECTED.
FRIDAY...MAY GET A BRIEF PERIOD OF SUB-SCA CONDITIONS THOUGH SEAS
COULD REMAIN NEAR 5 FEET, REQUIRING AN EXTENSION TO THE SMALL CRAFT
ADVISORY.
FRIDAY NIGHT THROUGH SATURDAY...SCA CONDITIONS EXPECTED
(80-90%) WITH NORTHWEST WINDS 25-30 KT AND SEAS AROUND 4 TO 6
FEET. .
FIRE WEATHER
TODAY, VERY DRY CONDITIONS ARE EXPECTED TO CONTINUE. WINDS WILL
GENERALLY BE NEAR 5-10 MPH WITH A FEW GUSTS UP TO 15 MPH, MUCH LOWER
THAN TUESDAY. A VERY DRY AIRMASS WILL BE IN PLACE HOWEVER WITH
MINIMUM RH VALUES GENERALLY BETWEEN 20 TO 30 PERCENT, WITH THE
EXCEPTION OF THE IMMEDIATE COASTAL AREA.
NOT EXPECTING ANY CONCERNS ON THURSDAY AS A WEAK SYSTEM
APPROACHES, BRINGING SOME MOISTURE AND MINIMUM RHS GENERALLY
BETWEEN 40-60% AND LIGHT WINDS.
ATTENTION TURNS TO THE FRIDAY-SUNDAY PERIOD AS ANOTHER PERIOD OF
VERY DRY CONDITIONS ARE EXPECTED WITH MINIMUM RH VALUES
CURRENTLY FORECAST TO BE IN THE 25-35% RANGE. ELEVATED CONCERN
FOR SATURDAY AS WINDS WILL BE GUSTING BETWEEN 20-30 MPH OUT OF
THE NORTHWEST. WINDS WILL BE LIGHTER ON FRIDAY AND SUNDAY.
TIDES/COASTAL FLOODING
A COASTAL FLOOD ADVISORY REMAINS IN EFFECT FOR CAPE MAY COUNTY,
NJ AND SUSSEX COUNTY, DE THROUGH 10 AM AS MINOR TIDAL FLOODING
IS ONGOING. ELSEWHERE ALONG THE NJ COAST, ONLY SPOTTY MINOR
TIDAL FLOODING IS EXPECTED.
CONFIDENCE HAS INCREASED THAT A COMBINATION OF PERSISTENT SHORE
PARALLEL WINDS AND INCREASING ASTRONOMICAL TIDES WITH A FULL
MOON ON FRIDAY LOOK TO LEAD TO COASTAL FLOODING FOR THE BACK
HALF OF THE WEEK. WIDESPREAD MINOR TIDAL FLOODING IS EXPECTED
ALONG THE ATLANTIC OCEAN COASTS OF NEW JERSEY AND DELAWARE AND
THE ASSOCIATED BACKBAYS AS WELL AS WITHIN DELAWARE BAY BEGINNING
WITH THE THURSDAY MORNING HIGH TIDE. THE THREAT FOR MODERATE
TIDAL FLOODING HAS DECREASED BUT MADE NO CHANGE TO THE COASTAL
FLOOD WATCH FOR NOW AS THE POTENTIAL STILL REMAINS. HOWEVER,
THINKING THAT THIS IS MORE OF A HIGH-END MINOR EVENT.
BY THURSDAY AND INTO FRIDAY, TIDAL PILING INTO THE LOWER DELAWARE
BAY LOOKS TO RESULT IN MINOR TIDAL FLOODING OCCURING FURTHER
NORTH, ALONG THE SHORES OF THE UPPER DELAWARE BAY AS WELL AS THE
TIDAL DELAWARE RIVER.
COASTAL FLOODING IS NOT EXPECTED TO OCCUR ALONG THE CHESAPEAKE
BAY IN THE EASTERN SHORE OF MARYLAND.
PHI WATCHES/WARNINGS/ADVISORIES
PA...NONE.
NJ...COASTAL FLOOD WATCH FROM LATE TONIGHT THROUGH FRIDAY MORNING
FOR NJZ012>014-020-022>027.
COASTAL FLOOD ADVISORY UNTIL 10 AM EST THIS MORNING FOR NJZ023-
024.
DE...COASTAL FLOOD WATCH FROM LATE TONIGHT THROUGH FRIDAY MORNING
FOR DEZ002>004.
COASTAL FLOOD ADVISORY UNTIL 10 AM EST THIS MORNING FOR DEZ003-
004.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST EARLY THIS MORNING FOR
ANZ430-431.
SMALL CRAFT ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR ANZ450.
SMALL CRAFT ADVISORY UNTIL 6 AM EST FRIDAY FOR ANZ451>455.
SYNOPSIS...HOEFLICH
NEAR TERM...JOHNSON
SHORT TERM...HOEFLICH
LONG TERM...HOEFLICH
AVIATION...HOEFLICH/JOHNSON
MARINE...HOEFLICH/JOHNSON
FIRE WEATHER...HOEFLICH/JOHNSON
TIDES/COASTAL FLOODING...AKL/HOEFLICH
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page