864
FXUS61 KPHI 161849
AFDPHI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
149 PM EST SUN FEB 16 2025
SYNOPSIS
LOW PRESSURE WILL MOVE NORTHEASTWARD THROUGH THE REGION TODAY.
A COLD FRONT ASSOCIATED WITH THIS LOW WILL MOVE THROUGH OUR AREA
LATE THIS AFTERNOON INTO EARLY THIS EVENING. HIGH PRESSURE WILL
SLOWLY BUILD TOWARDS OUR REGION THROUGH THE FIRST HALF OF THE
WEEK. A COASTAL STORM MAY IMPACT THE REGION WEDNESDAY NIGHT
THROUGH THURSDAY. HIGH PRESSURE RETURNS THEREAFTER.
NEAR TERM /THROUGH MONDAY/
A STRONG STORM SYSTEM WILL CONTINUE TO IMPACT THE REGION TODAY
INTO MONDAY WITH THE MAIN HAZARD ASSOCIATED WITH THE STORM BEING
THE STRONG, DAMAGING WINDS THAT ARE STILL EXPECTED IN THE WAKE
OF ITS COLD FRONT.
AS OF 145 PM THIS AFTERNOON, A LARGE AND DEEPENING AREA OF LOW
PRESSURE WAS CENTERED NEAR CENTRAL PA. A WARM FRONT EXTENDS EAST
FROM THE LOW ACROSS SE PA INTO SOUTHERN NJ WITH A COLD FRONT
EXTENDING SOUTHWARD INTO PORTIONS OF VIRGINIA AND THE CAROLINAS.
THERE IS A STRONG TEMPERATURE GRADIENT ACROSS THE AREA IN
ASSOCIATION WITH THE WARM FRONT AS IT'S SEPARATING TEMPERATURES
IN THE 50S AND 60S SOUTH OF THE FRONT VS. 30S AND 40S NORTH OF
THE FRONT. IN FACT IT'S STILL IN THE LOW 30S OVER MOUNT POCONO!
WE'VE HAD AN INITIAL AREA OF SOME HEAVY SHOWERS MOVE THROUGH AND
THIS WILL BE MOVING OFF THE COAST WITHIN THE NEXT HOUR OR TWO.
MOST AREAS SHOULD THEN SEE A LULL BEFORE THE COLD FRONT SWEEPS
THROUGH FROM WEST TO EAST DURING THE LATTER HALF OF THE
AFTERNOON (ROUGHLY AROUND 3 PM FOR OUR WESTERN ZONES, CLEARING
THE COAST BY AROUND 6 PM). SOME ADDITIONAL SHOWERS WILL BE
POSSIBLE AS THIS OCCURS. OTHERWISE, THE MAIN FOCUS WILL BE
SHIFTING TO THE VERY STRONG WINDS THAT ARE STILL EXPECTED WITH A
WIND WARNING IN EFFECT AREA WIDE. WINDS HAVE HAVE BEEN A BIT
SLOW TO COME UP SO FAR DUE TO THE SLOWER THAN EXPECTED PROGRESS
OF THE WARM FRONT NORTHWARD BUT WE HAVE STARTED TO SEE SOME
SOUTHERLY WIND GUSTS OF 30 TO 40+ MPH OVER PORTIONS OF DELMARVA
AS WELL AS SOUTHERN AND COASTAL NJ SOUTH OF THE WARM FRONT IN
THE WARM SECTOR.
IN THE WAKE OF THE STRONG COLD FRONT PASSING THROUGH AROUND 3
PM TO 6 PM, TEMPERATURES WILL PLUMMET WITH WIND CHILLS IN THE
TEENS BY LATE TONIGHT. THE MAIN CONCERN FOR LATE THIS AFTERNOON
AND EVENING THROUGH MONDAY WILL BE THE STRONG TO DAMAGING WEST
TO NORTHWEST WINDS DEVELOPING.
THE SYNOPTIC PATTERN IS VERY FAVORABLE FOR HIGH WINDS. SURFACE
PRESSURE RISES EXCEEDING 1 MB/HOUR, PERHAPS AS MUCH AS 8 MB
WITHIN JUST 3 HOURS, AND VERY STRONG COLD ADVECTION WILL SUPPORT
EFFICIENT BOUNDARY LAYER MIXING IMMEDIATELY IN THE WAKE OF THE
FRONTAL PASSAGE AND OVERNIGHT TONIGHT INTO MONDAY. A CONSENSUS
OF DETERMINISTIC BUFKIT PROFILES AND HREF ENSEMBLE PROFILES
INDICATE BOUNDARY LAYER MIXING THROUGH THE 925 MB LAYER, AND
PERHAPS AS HIGH AS THE 850 MB LAYER AT TIMES. WIND SPEEDS AT
THESE LEVELS AROUND 35-50 KTS SHOULD SERVE AS A GOOD PROXY FOR
WIND GUSTS GIVEN THE EFFICIENT MIXING. 925 MB WINDS LIKELY
SERVING AS A MORE PREVAILING WIND GUST PROXY, WITH 850 MB WINDS
SERVING AS A PEAK GUST PROXY. THIS WILL TRANSLATE TO FREQUENT
WESTERLY GUSTS IN THE 45-60 MPH RANGE ACROSS THE ENTIRE AREA,
WITH THE STRONGEST WINDS MOST LIKELY OCCURRING ACROSS THE HIGHER
ELEVATIONS AND NEAR THE COASTS. THE PEAK GUSTS OF THE EVENT
NEAR 50-60 MPH ARE LIKELY TO OCCUR IMMEDIATELY IN THE WAKE OF
THE FRONTAL PASSAGE. THIS WILL BE WHEN THE AFOREMENTIONED
BOUNDARY LAYER WIND SPEEDS ARE STRONGEST AND SURFACE PRESSURE
RISES ARE SHARPEST. THEREAFTER, WESTERLY GUSTS OF 40-55 MPH WILL
LIKELY PREVAIL FOR MUCH OF TONIGHT THROUGH AT LEAST THE FIRST
HALF OF MONDAY BEFORE BEGINNING TO SUBSIDE. THE HIGH WIND
WARNING REMAINS IN EFFECT FOR AN EXTENDED PERIOD OF IMPACTS FROM
HIGH WINDS.
WHILE THE PEAK GUSTS UPWARDS OF 60 MPH ARE NOT EXPECTED TO
PREVAIL DURING THE ENTIRE WARNING PERIOD, WET SOILS COMBINED
WITH THE HIGH WINDS COULD RESULT IN EXTENSIVE TREE DAMAGE
THROUGH THE EVENT. ADDITIONALLY, THE STRONG WINDS WILL USHER IN
MUCH COLDER AIR, WITH TEMPERATURES IN THE 20S AND 30S AND WIND
CHILLS IN THE TEENS. WE ARE MOST CONCERNED ABOUT THE POTENTIAL
FOR POWER OUTAGES COMBINED WITH THE COLD, WHICH COULD EXACERBATE
THE IMPACTS OF THIS HIGH WIND EVENT FOR FOLKS THAT LOSE POWER
WITH IT BEING SO COLD OUT. PLEASE TAKE THIS EVENT SERIOUSLY!
AS PREVIOUSLY MENTIONED, LOW TEMPERATURES TONIGHT INTO MONDAY
MORNING WILL BE MAINLY IN THE 20S TO NEAR 30 DEGREES WITH WIND
CHILLS DROPPING INTO THE TEENS. TEMPERATURES WILL STRUGGLE TO
CLIMB FROM MORNING MINIMUMS ON MONDAY, WITH HIGHS GENERALLY
RANGING FROM THE 20S NORTH TO THE 30S SOUTH. BUT WITH THE WIND
CHILL, IT WILL FEEL A GOOD 10 TO 15 DEGREES COLDER THAN THE
ACTUAL TEMPERATURES.
SHORT TERM /MONDAY NIGHT THROUGH TUESDAY NIGHT/
THE MAIN CONCERN IN THE SHORT TERM IS DANGEROUSLY COLD
CONDITIONS BOTH MONDAY NIGHT AND TUESDAY NIGHT.
HIGH PRESSURE WILL SLOWLY BUILD CLOSER TO THE REGION FROM THE
WEST. WITH THE DEPARTING LOW, THERE WILL STILL BE A TIGHT
PRESSURE GRADIENT INTO TUESDAY MORNING, SO EXPECT BREEZY
CONDITIONS THROUGH THAT PERIOD. BECAUSE WINDS WILL STAY UP A
BIT, RADIATIVE COOLING WILL BE LIMITED. HOWEVER, WITH STRONG
COLD AIR ADVECTION BEHIND TODAY'S COLD FRONT, WIND CHILLS BOTH
MONDAY NIGHT AND TUESDAY NIGHT COULD GET CLOSE TO COLD WEATHER
ADVISORY CONDITIONS. MINIMUM WIND CHILLS BOTH NIGHTS ARE
EXPECTED TO BE IN THE SINGLE DIGITS ABOVE ZERO GENERALLY FOR THE
COASTAL PLAIN, AND BELOW ZERO FOR AREAS NORTH AND WEST OF THE
FALL LINE. IN THE HIGHER TERRAIN OF THE POCONOS AND NW NJ, WIND
CHILLS COULD BE LESS THAN -10 F. THIS COULD BE ESPECIALLY
IMPACTFUL IF THERE ARE ANY LINGERING POWER OUTAGES AFTER THE
STRONG WINDS EXPECTED IN THE NEAR TERM.
DRY CONDITIONS ARE LIKELY THROUGH THE PERIOD. SOME MODELS
DEPICT LAKE EFFECT SNOW SHOWERS WELL NORTHWEST OF OUR REGION,
BUT THE FETCH LOOKS UNFAVORABLE FOR THOSE TO MAKE IT AS FAR
SOUTHEAST AS OUR AREA.
LONG TERM /WEDNESDAY THROUGH SUNDAY/
THE FOCUS IN THE LONG TERM IS ON THE COASTAL STORM LATE
WEDNESDAY THROUGH THURSDAY WHICH HAS THE POTENTIAL TO BRING
SNOW, ESPECIALLY TO THE COASTAL PLAINS. NO MAJOR CHANGES IN THE
FORECAST, THOUGH THERE REMAINS UNCERTAINTY, ESPECIALLY WITH THE
TIMING OF THE SYSTEM, AND THUS ULTIMATELY WITH THE IMPACTS OF
THE SYSTEM.
GUIDANCE HAS COME INTO PRETTY GOOD AGREEMENT OF THE TRACK OF
THE LOW. A LARGE CLUSTER OF GUIDANCE DEPICTS THE CENTER OF THE
SURFACE LOW PROGRESSING OFF THE COAST IN NORTHERN FL, THEN
STAYING CLOSE TO THE COAST UP THROUGH THE OUTER BANKS, BEFORE
TRACKING NORTHEASTWARD, FURTHER AWAY FROM THE COAST. THERE IS
NOT ONLY GOOD AGREEMENT BETWEEN MODELS, BUT THIS IS ALSO CLOSE
TO THE CONSENSUS TRACK FROM THE SATURDAY MORNING MODEL RUN.
HOWEVER, WHERE THERE REMAINS UNCERTAINTY IS SOME MODELS DEPICT
THIS AS A SLOW MOVING SYSTEM THAT IS THUS ABLE TO ADVECT
MOISTURE MUCH FURTHER INLAND AND THUS HAS A LARGER FOOTPRINT OF
PRECIP TO THE LEFT OF THE LOW, BRINGING SNOW TO OUR AREA FROM
WEDNESDAY NIGHT THROUGH THURSDAY EVENING. OTHER GUIDANCE SHOWS A
FAST MOVING SYSTEM, AFFECTING OUR REGION FROM THE LATER HALF OF
THE DAY ON WEDNESDAY THROUGH THURSDAY MORNING.
THE PROBABILITIES FROM THE NATIONAL BLEND OF MODELS (NBM)
HAVEN'T CHANGED MUCH FROM THE PREVIOUS SHIFT: A 20 TO 40 PERCENT
PROBABILITY FOR MORE THAN 4 INCHES OF SNOW NORTH AND WEST OF
THE I-95 CORRIDOR AND A 40 TO 70 PERCENT PROBABILITY FOR MORE
THAN 4 INCHES OF SNOW ACROSS THE I-95 CORRIDOR AND COASTAL
PLAINS IN THE 48 HOUR PERIOD FROM 7 AM WEDNESDAY THROUGH 7 AM
FRIDAY; A 20 TO 30 PERCENT PROBABILITY FOR MORE THAN 8 INCHES OF
SNOW NORTH AND WEST OF THE I- 95 CORRIDOR AND A 30 TO 50
PERCENT PROBABILITY FOR MORE THAN 8 INCHES OF SNOW ACROSS
SOUTHERN NEW JERSEY, THE EASTERN SHORES OF MARYLAND AND DELAWARE
IN THE 48 HOUR PERIOD FROM 7 AM WEDNESDAY THROUGH 7 AM FRIDAY;
AND A 20 TO 30 PERCENT PROBABILITY FOR MORE THAN 12 INCHES OF
SNOW FOR THE COASTAL PLAINS.
CANADIAN HIGH PRESSURE BUILDS BACK IN FROM THE WEST FOR FRIDAY
AND SATURDAY WITH A RETURN TO DRY CONDITIONS.
AVIATION /19Z SUNDAY THROUGH FRIDAY/
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
THIS AFTERNOON...IFR OR LOWER IN LOW CLOUDS, MIST, AND SHOWERS
UNTIL A COLD FRONT MOVES THROUGH WEST TO EAST...THIS WILL OCCUR
AN HOUR OR TWO EITHER SIDE OF 21Z. FOLLOWING THE PASSAGE OF THE
FRONT, WINDS SHIFT TO STRONG WESTERLY AT 20 TO 30 GUSTING 40 TO
50 KNOTS. THIS WILL BRING IMPROVING VISBYS AND CIGS INITIALLY
BACK UP TO MVFR RIGHT AFTER THE FRONT PASSES AND THEN TO VFR FOR
MOST SITES BY EARLY THIS EVENING.
TONIGHT...VFR. WESTERLY WINDS SHOULD DECREASE SLIGHTLY, BUT
GUSTS NEAR OR ABOVE 40 KT STILL POSSIBLE.
MONDAY...VFR. WESTERLY WINDS GUSTING NEAR 40KT ESPECIALLY EARLY
IN THE DAY.
OUTLOOK...
MONDAY NIGHT THROUGH WEDNESDAY...VFR.
WEDNESDAY NIGHT THROUGH THURSDAY...SUB-VFR LIKELY IN SN.
MARINE
A STRONG COLD FRONT WILL PASS QUICKLY OFFSHORE AROUND 4 PM TO 6
PM. THE FRONT WILL BRING AND ABRUPT SHIFT IN WIND DIRECTION TO
WESTERLY. STORM FORCE GUSTS NEAR 50 KTS ARE ANTICIPATED FOR A
FEW HOURS FOLLOWING THE COLD FRONT, WHICH HAS PROMPTED THE
UPGRADE TO A STORM WARNING FOR THE PERIOD. FOLLOWING THE STORM
WARNING, A GALE WARNING WILL BE NEEDED THROUGH MONDAY. SEAS 5-9
FEET TONIGHT INTO MONDAY.
LOW WATER IS POSSIBLE NEAR THE TIMES OF LOW TIDE BEGINNING
TONIGHT THROUGH TUESDAY.
OUTLOOK...
MONDAY NIGHT AND TUESDAY...WINDS AND SEAS WILL GRADUALLY
SUBSIDE BELOW SCA CRITERIA THROUGH THE EARLY PART OF THE DAY
TUESDAY.
TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...WINDS AND SEAS SHOULD
STAY BELOW SCA CRITERIA.
THURSDAY...SCA CONDITIONS ARE POSSIBLE, ESPECIALLY ON THE
ATLANTIC COASTAL WATERS.
PHI WATCHES/WARNINGS/ADVISORIES
PA...HIGH WIND WARNING UNTIL 6 PM EST MONDAY FOR PAZ054-055-060>062-
070-071-101>106.
NJ...HIGH WIND WARNING UNTIL 6 PM EST MONDAY FOR NJZ001-007>010-
012>027.
DE...HIGH WIND WARNING UNTIL 6 PM EST MONDAY FOR DEZ001>004.
MD...HIGH WIND WARNING UNTIL 6 PM EST MONDAY FOR MDZ012-015-019-020.
MARINE...DENSE FOG ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR ANZ430-
431-450>454.
STORM WARNING UNTIL 6 AM EST MONDAY FOR ANZ430-431-450>455.
LOW WATER ADVISORY FROM MIDNIGHT TONIGHT TO 8 AM EST MONDAY
FOR ANZ450.
SYNOPSIS...JOHNSON/MPS
NEAR TERM...FITZSIMMONS/STAARMANN
SHORT TERM...JOHNSON
LONG TERM...JOHNSON/MPS
AVIATION...FITZSIMMONS/JOHNSON/MPS
MARINE...JOHNSON/STAARMANN
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