987
FXUS61 KPHI 120824
AFDPHI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
324 AM EST TUE NOV 12 2024
SYNOPSIS
HIGH PRESSURE BEGINS TO MOVE IN TODAY, REMAINING IN CONTROL THROUGH
WEDNESDAY NIGHT. THIS WILL GIVE WAY TO A WEAK SYSTEM ON THURSDAY AND
LOW CHANCES FOR LIGHT SHOWERS. HIGH PRESSURE WILL THEN SETTLE INTO
THE OHIO VALLEY INTO THE WEEKEND LEADING TO MORE DRY WEATHER AND
MODERATING TEMPERATURES.
NEAR TERM /THROUGH TONIGHT/
AS OF 3 AM, THE COLD FRONT WAS CROSSING THROUGH SOUTH JERSEY AND
NORTHERN DELMARVA. EARLIER BAND OF SHOWERS HAS DISSIPATED. THERE ARE
A FEW LAKE EFFECT ENHANCED BANDS OF SHOWERS WELL TO OUR NORTHWEST,
BUT I DON'T EXPECT THOSE TO GET ANY CLOSER TO OUR REGION. DRY
CONDITIONS, WITH SCATTERED LOW AND MID LEVEL CLOUDS ARE EXPECTED
THROUGH THE DAY.
THE BIG CHANGES THE FRONT WILL USHER IN ARE WINDY CONDITIONS, AND
CONSIDERABLE DRY AND COLD AIR ADVECTION THROUGH THE DAY.
WITH REGARDS TO THE WINDS, UPSTREAM WINDS HAVE GUSTED AS HIGH AS 40
MPH. HOWEVER, GUSTS THAT HIGH HAVE BEEN PRIMARILY CONFINED TO HIGHER
ELEVATIONS. CERTAINLY COULD SEE GUSTS UP TO 35 MPH THROUGH THE DAY,
BUT WITH THE STRONGEST PRESSURE RISES COMING BEFORE 15Z, AND A
ROBUST INVERSION AROUND 850 TO 700 MB, WINDS SHOULD REMAIN WELL
BELOW WIND ADVISORY CRITERIA. WINDS WILL LIKELY DIMINISH QUICKLY
EARLY THIS EVENING.
DEWPOINTS ARE CURRENTLY IN THE 30S TO LOWER 40S, BUT BASED ON MODEL
SOUNDINGS AND UPSTREAM OBSERVATIONS, EXPECT DEWPOINTS TO DROP INTO
THE 20S BY THE END OF THE DAY. SEE DETAILS BELOW REGARDING FIRE
WEATHER RISK TODAY.
AS FOR TEMPERATURES, THANKS TO SIGNIFICANT COLD AIR ADVECTION,
EXPECT HIGH TEMPERATURES TO BE 10 TO 20 DEGREES LOWER THAN WHAT WE
SAW YESTERDAY - MOSTLY IN THE 50S, WITH THE EXCEPTION OF THE HIGHER
TERRAIN OF THE SOUTHERN POCONOS AND NW NJ, WHICH WILL STAY IN THE
40S. THOUGH WINDS WON'T COMPLETELY DECOUPLE OVERNIGHT, TEMPERATURES
BELOW FREEZING ARE EXPECTED ACROSS THE REGION TONIGHT WITH THE
EXCEPTION OF THE IMMEDIATE COAST.
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/
THE WEDNESDAY THROUGH WEDNESDAY NIGHT PERIOD WILL FEATURE BUILDING
AND THEN RETREATING UPPER LEVEL AND SURFACE RIDGING. THE SURFACE
HIGH WILL GRADUALLY PASS WELL TO OUR NORTH ACROSS SOUTHEAST CANADA
ON WEDNESDAY, LOCKING IN BELOW NORMAL TEMPERATURES AND A VERY DRY
AIRMASS IN PLACE. STILL LOOKING AT ABUNDANT SUNSHINE HOWEVER. BELOW
NORMAL TEMPERATURES WILL PERSIST THROUGH WEDNESDAY WITH HIGHS FROM
THE UPPER 40S IN THE HIGHER ELEVATIONS TO LOW TO MID 50S ELSEWHERE.
LOWS ON WEDNESDAY NIGHT WILL BE IN THE MID TO UPPER 20S/LOW 30S WITH
MID TO UPPER 30S/LOW 40S NEAR THE COAST AS A LIGHT ONSHORE FLOW WILL
BRING SOME MORE MILD AIR.
A DECAYING TROUGH AND ASSOCIATED SURFACE LOW WILL MOVE TOWARD THE
AREA ON THURSDAY, WITH THE SURFACE LOW PASSING TO OUR SOUTH THURSDAY
NIGHT. GUIDANCE STILL SUPPORTS THIS SYSTEM BRING A FEW LIGHT SHOWERS
INTO OUR AREA, ESPECIALLY NEAR AND SOUTH OF THE PHILLY METRO
FROM LATE AFTERNOON THURSDAY AND THROUGH THE EVENING. ANY
MEASURABLE RAINFALL WITH THIS ACTIVITY WILL BE VERY MINIMAL,
LIKELY LESS THAN 0.10" FOR MOST, THOUGH SOME AREAS IN SOUTHERN
DELMARVA COULD GET INTO THE QUARTER INCH TO HALF INCH RANGE. NOT
MUCH TO WRITE HOME ABOUT, BUT WE'LL CERTAINLY TAKE ANYTHING WE
CAN GET WITH THE ONGOING SEVERE TO EXTREME DROUGHT. EXPECTING AN
OVERCAST DAY OVERALL WITH HIGHS IN THE UPPER 40S/LOW 50S. LOWS
THURSDAY NIGHT WILL BE MOSTLY IN THE MID 30S TO NEAR 40 DEGREES
UNDER CLOUDY SKIES WITH LIGHT WINDS. THE AREAS COLD ENOUGH FOR
FROZEN PRECIP ARE LEAST LIKELY TO GET ANYTHING AT ALL.
LONG TERM /FRIDAY THROUGH MONDAY/
THE WEAK SYSTEM MOVES OUT BY FRIDAY WITH UPPER LEVEL RIDGING
BUILDING 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 START IN THE MID TO UPPER 50S ON
FRIDAY, POTENTIALLY GETTING INTO THE 60S SATURDAY THROUGH MONDAY.
COULD BE A BIT BREEZY ON SATURDAY WITH A TIGHT GRADIENT IN PLACE DUE
TO THE INCOMING HIGH AND AN AREA OF LOW PRESSURE NEAR THE CANADIAN
MARITIMES. WITH DRY NORTHERLY FLOW EXPECTED, THIS COULD BRING SOME
FIRE WEATHER CONCERNS, BUT STILL A LONG WAY OUT TO DETERMINE HOW LOW
RHS WILL GO. OVERALL THOUGH, A QUIET AND DRY WEEKEND EXPECTED.
A FRONTAL SYSTEM LOOKS TO APPROACH ON MONDAY WHICH COULD BRING A FEW
SHOWERS AND A POTENTIAL END TO THE ABOVE NORMAL TEMPERATURES.
AVIATION /08Z TUESDAY THROUGH SATURDAY/
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
THROUGH TODAY...VFR WITH MID LEVEL CLOUDS AROUND 4000 FT AGL
GRADUALLY ERODING. THE FRONT WILL CROSS THROUGH ALL TAF SITES BEFORE
12Z. ONCE IT DOES, EXPECT NORTHWEST WINDS GUSTING UP TO 20 KT BEFORE
12Z, AND UP TO 30 KT DURING THE DAY TIME HOURS. HIGH CONFIDENCE.
TONIGHT...VFR CONDITIONS EXPECTED. WIND SPEEDS SHOULD DROP OFF
QUICKLY AROUND 00Z, REMAINING NEAR 10 KT FOR MUCH OF THE NIGHT.
OUTLOOK...
WEDNESDAY THROUGH THURSDAY...VFR. SOME SHOWERS POSSIBLE LATE
THURSDAY.
THURSDAY NIGHT...MVFR/IFR CONDITIONS POSSIBLE, ESPECIALLY SOUTH OF
PHILADELPHIA WITH SHOWERS AND LOW CLOUDS MOVING THROUGH.
FRIDAY THROUGH SATURDAY...VFR. SOME GUSTY WINDS POSSIBLE ON SATURDAY
WITH GUSTS UP TO 25 KT POSSIBLE.
MARINE
SMALL CRAFT ADVISORY REMAINS IN EFFECT FOR ALL OF THE DELAWARE BAY
AND THE ATLANTIC COASTAL WATERS ADJACENT TO NEW JERSEY AND DELAWARE.
COLD FRONT IS QUICKLY APPROACHING THE COAST AND WILL BE USHERING IN
AN ABRUPT WIND SHIFT AND WIND SPEED INCREASE AS IT MOVES FURTHER
SOUTHEAST. WITH THE FRONT, EXPECT NORTHWEST WINDS GUSTING NEAR 30
KT. AT THIS POINT, IT LOOKS VERY LIKELY THAT WINDS WILL STAY BELOW
GALE FORCE. HOWEVER, WILL BE WATCHING TRENDS ON THE DELAWARE BAY
CLOSELY AS THIS IS A FAVORED WIND DIRECTION FOR THE FUNNELING EFFECT
DOWN THE BAY WHICH RESULTS IN A LOW BIAS OF MODEL WIND SPEEDS. WITH
THIS IN MIND, FORECAST WIND SPEEDS FOR THE BAY AND THE ATLANTIC
WATERS IMMEDIATELY EAST OF THE BAY ARE WELL ABOVE THE MODEL
CONSENSUS, BUT STILL BELOW GALE FORCE.
BY THIS EVENING, WINDS WILL BECOME MORE NORTHERLY AND WIND SPEEDS
WILL DIMINISH SLIGHTLY, THOUGH SCA CONDITIONS WILL CONTINUE THROUGH
THE OVERNIGHT HOURS.
OUTLOOK...
WEDNESDAY...SMALL CRAFT ADVISORY WAS EXTENDED FOR ALL COASTAL WATERS
THROUGH NOON AS WIND GUSTS AROUND 25-30 KT AND SEAS 5 TO 6 FEET ARE
EXPECTED. THE SCA EXPIRES AT NOON FOR ANZ450, WITH THE SCA REMAINING
IN THROUGH THE REST OF WEDNESDAY FOR THE REMAINING OCEAN ZONES AS
LINGERING 5 FOOT SEAS ARE EXPECTED SOUTH OF MANASQUAN INLET THROUGH
THE EVENING. NO MARINE HEADLINES EXPECTED ON DELAWARE BAY.
WEDNESDAY NIGHT THROUGH FRIDAY NIGHT...NO MARINE HEADLINES EXPECTED,
THOUGH CANNOT RULE OUT SCA CONDITIONS CONTINUING WITH 5 FOOT SEAS
POSSIBLE (20-30%) THROUGH THE END OF THE WEEK.
SATURDAY...SCA CONDITIONS LIKELY (60-70%) WITH SEAS AROUND 5 FEET
AND WINDS GETTING NEAR 25 KT.
FIRE WEATHER
DESPITE RECENT RAINFALL AND RH'S INCREASING OVERNIGHT A
SECONDARY COLD FRONT WILL CAUSE ANOTHER PERIOD OF GUSTY WINDS
AND DRY CONDITIONS THROUGH MID-WEEK, ESPECIALLY TODAY.
MINRH VALUES ARE FORECAST TO FALL AS LOW AS 30-40% WITH GUSTY
NORTHWEST WINDS AROUND 30-35 MPH - LOCALLY UP TO 40 MPH IN THE
HIGHER TERRAIN FOR TODAY. UPON DISCUSSION WITH OUR FIRE WEATHER
PARTNERS, HAVE ISSUED A SPECIAL WEATHER STATEMENT FOR MD, NJ
AND DE FOR TODAY.
FOR WEDNESDAY, DRY CONDITIONS ARE EXPECTED TO CONTINUE. WINDS
WILL GENERALLY BE NEAR 5-10 MPH. THE LOWEST RH WILL OCCUR ON
WEDNESDAY, WITH WIDESPREAD MINIMUM VALUES IN THE 20-30% RANGE.
ANY RAINFALL THAT OCCURS WITH SOME SHOWERS ON THURSDAY WILL BE
VERY MINIMAL AT BEST. RH THURSDAY NEAR 35-50%.
LOOKING FARTHER AHEAD, RH VALUES REMAIN IN THE 30-40% RANGE FOR
FRIDAY AND INTO THE WEEKEND ALONG WITH SOME BREEZY CONDITIONS.
TIDES/COASTAL FLOODING
A COMBINATION OF PERSISTENT SHORE PARALLEL WINDS AND INCREASING
ASTRONOMICAL TIDES WITH A FULL MOON ON FRIDAY LOOK TO LEAD TO
SOME COASTAL FLOODING CONCERNS FOR THE BACK HALF OF THIS WEEK.
THE MOST LIKELY LOCATIONS TO BE IMPACTED BY TIDAL FLOODING WOULD
BE ALONG THE ATLANTIC OCEAN COASTS OF NEW JERSEY AND DELAWARE
AND THE ASSOCIATED BACKBAYS. SPOTTY MINOR TIDAL FLOODING MAY
OCCUR AS EARLY AS THE WEDNESDAY MORNING HIGH TIDE BUT ANY
WIDESPREAD FLOODING IS FORECAST TO HOLD OFF UNTIL THE THURSDAY
MORNING HIGH TIDE. FURTHER UPDATES WITH GREATER SPECIFICITY IN
THE TIMING AND EXTENT OF ANY IMPACTS WILL COME AS UNCERTAINTY
DECREASES.
COASTAL FLOODING IS NOT EXPECTED TO OCCUR ALONG THE CHESAPEAKE
BAY IN THE EASTERN SHORE OF MARYLAND AND ALONG THE TIDAL
DELAWARE RIVER.
PHI WATCHES/WARNINGS/ADVISORIES
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 1 AM EST WEDNESDAY FOR ANZ430-431.
SMALL CRAFT ADVISORY UNTIL NOON EST WEDNESDAY FOR ANZ450.
SMALL CRAFT ADVISORY UNTIL 6 PM EST WEDNESDAY FOR ANZ451>455.
SYNOPSIS...HOEFLICH/STAARMANN
NEAR TERM...JOHNSON
SHORT TERM...HOEFLICH/STAARMANN
LONG TERM...HOEFLICH
AVIATION...HOEFLICH/JOHNSON
MARINE...HOEFLICH/JOHNSON
FIRE WEATHER...HOEFLICH/JOHNSON
TIDES/COASTAL FLOODING...AKL
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page