120
FXUS61 KPHI 170543
AFDPHI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1243 AM EST MON FEB 17 2025
SYNOPSIS
LOW PRESSURE LIFTS THROUGH THE NORTHEAST EARLY THIS EVENING,
AND THIS WILL DRAG A COLD FRONT THROUGH THE REGION TONIGHT. HIGH
PRESSURE BUILDS IN FROM THE WEST FOR THE FIRST HALF OF THE NEW
WEEK. COASTAL LOW PRESSURE MAY AFFECT THE AREA WEDNESDAY NIGHT
THROUGH THURSDAY. HIGH PRESSURE RETURNS TO CLOSE OUT THE NEW
WEEK.
NEAR TERM /THROUGH TODAY/
KEEPING WIND HEADLINES AS IS FOR NOW THOUGH WE HAVE SEEN WINDS
DIMINISH SLIGHTLY OVER THE LAST 2 HOURS. MODEL SOUNDS STILL SHOW
POTENTIAL, ESPECIALLY FOR RIDGE LINES, OF GUSTS NEAR 50KT. WILL
WATCH THE TRENDS OVER THE NEXT FEW HOURS TO SEE IF THIS HOLDS.
AS OF EARLY MONDAY MORNING, THE CENTER OF THE LOW AND THE COLD
FRONT CONTINUE TO PROGRESS FURTHER AWAY FROM THE REGION. THOUGH
THESE FEATURES ARE MOVING AWAY FROM THE AREA, THE PATTERN
REMAINS 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 THROUGH MUCH OF THE DAY TODAY. 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. WESTERLY GUSTS OF 40-55 MPH
WILL LIKELY PREVAIL THROUGH THE FIRST HALF OF MONDAY BEFORE
BEGINNING TO SUBSIDE.
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 /TONIGHT THROUGH TUESDAY NIGHT/
ARCTIC HIGH PRESSURE BUILDS IN FROM THE WEST AND AN ARCTIC
AIRMASS SPREADS INTO THE REGION. TEMPERATURES WILL RUN SOME 10
TO 15 DEGREES BELOW THE SEASONAL AVERAGES FOR THIS TIME OF THE
YEAR. 850 MB TEMPERATURES MONDAY NIGHT AND TUESDAY NIGHT WILL BE
FROM -18C TO -20C OVER THE SOUTHERN POCONOS, FAR NORTHWEST NEW
JERSEY, AND THE LEHIGH VALLEY TO -11C TO -17C FOR MOST OF NEW
JERSEY AND SOUTHEAST PENNSYLVANIA TO -8C TO -10C OVER DELMARVA.
THIS WILL RESULT IN LOW TEMPERATURES MONDAY NIGHT RANGING FROM
THE SINGLE DIGITS IN THE SOUTHERN POCONOS AND FAR NORTHWEST NEW
JERSEY TO THE TEENS FOR MOST OF NEW JERSEY AND SOUTHEAST NEW
JERSEY AND IN THE LOW 20S IN DELMARVA. A WESTERLY BREEZE OF 15
TO 20 MPH WILL YIELD MIN WIND CHILL VALUES AS LOW AS -15 IN THE
HIGHER ELEVATIONS OF THE SOUTHERN POCONOS TO 0 TO -5 IN MOST OF
NORTHERN NEW JERSEY AND SOUTHEAST PENNSYLVANIA, AND 5 TO 10 IN
SOUTHERN NEW JERSEY AND DELMARVA. WINDS MAY BE A BIT LIGHTER
TUESDAY NIGHT, BUT AIR TEMPERATURES MAY BE A DEGREE OR 2 COLDER,
RESULTING IN SIMILAR WIND CHILLS TUESDAY NIGHT COMPARED TO
MONDAY NIGHT.
MOSTLY SUNNY AND COLD ON TUESDAY WITH HIGHS GENERALLY IN THE
20S TO LOW 30S, THOUGH IN THE TEENS IN THE SOUTHERN POCONOS.
LONG TERM /WEDNESDAY THROUGH SUNDAY/
ALL EYES CONTINUE TO BE ON THE POTENTIAL COASTAL STORM GEARING
UP TO AFFECT THE MID-ATLANTIC AND NORTHEAST DURING THE MID-WEEK
PERIOD. HIGH PRESSURE OVER THE AREA SLIDES OFFSHORE ON
WEDNESDAY. MEANWHILE, A CLOSED H5 LOW MOVES INTO THE NORTHERN
PLAINS AND UPPER MIDWEST, AND A TROUGH WILL EXTEND DOWN FROM
THAT LOW AND INTO THE GULF COAST STATES. SURFACE LOW PRESSURE
WILL DEVELOP OUT AHEAD OF THAT TROUGH ON WEDNESDAY, AND THAT LOW
LIFTS TOWARDS THE MID-ATLANTIC.
THERE STILL IS PLENTY OF TIME FOR THE FINER DETAILS TO DEVELOP,
AND THERE IS STILL A GOOD DEAL OF UNCERTAINTY AMONG THE MODELS.
12Z/16 ECMWF HAS SIGNIFICANT SNOW ACCUMULATION OVER MOST OF
SOUTHERN NEW JERSEY AND DELMARVA, WHILE THE 12Z/16 CMC IS ALMOST
A COMPLETE MISS. 12Z/16 GFS KIND OF SPLITS THE DIFFERENCE.
12Z/16 GUIDANCE SEEMS TO HAVE SPED UP THE TIMING OF THE LOW,
WHERE THE IMPACTS WOULD BE MORE WEDNESDAY NIGHT, WITH THE LOW
DEPARTING THURSDAY MORNING. STILL QUITE COLD WITH HIGHS IN THE
20S TO AROUND 30 FOR BOTH WEDNESDAY AND THURSDAY, AND LOWS WILL
BE IN THE TEENS AND LOW 20S. THE FOCUS FOR THE HIGHEST SNOW
ACCUMULATIONS WILL BE OVER DELMARVA AND THE COASTAL PLAIN OF NEW
JERSEY. MODELS STILL COULD SHIFT BACK FARTHER TO THE WEST.
THE PROBABILITIES FROM THE NATIONAL BLEND OF MODELS (NBM) ARE
COMING INTO FOCUS. THE 13Z/16 INDICATES FOR THE 48 HOUR PERIOD
FROM 7 AM WEDNESDAY THROUGH 7 AM FRIDAY: 20 TO 40 PERCENT
PROBABILITY FOR MORE THAN 4 INCHES OF SNOW NORTH AND WEST OF THE
I-95 CORRIDOR; A 40 TO 60 PERCENT PROBABILITY FOR MORE THAN 4
INCHES OF SNOW ACROSS THE I-95 CORRIDOR; A 60 TO 80 PERCENT
PROBABILITY FOR MORE THAN 4 INCHES OF SNOW FOR THE EASTERN
SHORES OF MARYLAND, DELAWARE, AND THE COASTAL PLAIN OF NEW
JERSEY. FOR THE 48 HOUR PERIOD FROM 7 AM WEDNESDAY THROUGH 7 AM
FRIDAY: 10 TO 20 PERCENT PROBABILITY FOR MORE THAN 8 INCHES OF
SNOW NORTH AND WEST OF THE I-95 CORRIDOR; A 30 TO 40 PERCENT
PROBABILITY FOR MORE THAN 8 INCHES OF SNOW ACROSS THE I-95
CORRIDOR; A 40 TO 60 PERCENT PROBABILITY FOR MORE THAN 8 INCHES
OF SNOW FOR THE EASTERN SHORES OF MARYLAND, DELAWARE, AND THE
COASTAL PLAIN OF NEW JERSEY. FOR THE 48 HOUR PERIOD FROM 7 AM
WEDNESDAY THROUGH 7 AM FRIDAY: 10 PERCENT PROBABILITY FOR MORE
THAN 12 INCHES OF SNOW NORTH AND WEST OF THE I-95 CORRIDOR; A 20
TO 30 PERCENT PROBABILITY FOR MORE THAN 12 INCHES OF SNOW
ACROSS THE I-95 CORRIDOR; A 30 TO 40 PERCENT PROBABILITY FOR
MORE THAN 12 INCHES OF SNOW FOR THE EASTERN SHORES OF MARYLAND,
DELAWARE, AND THE COASTAL PLAIN OF NEW JERSEY.
HIGH PRESSURE BUILDS IN FROM THE WEST BEHIND THE DEPARTING
STORM AND WILL EVENTUALLY BUILD OVER THE AREA BY NEXT WEEKEND.
TEMPERATURES WILL STILL RUN 10 DEGREES BELOW THE SEASONAL
AVERAGES DURING THIS TIME WITH HIGHS IN THE MID TO UPPER 30S AND
LOWS IN THE TEENS AND LOW 20S.
AVIATION /06Z MONDAY THROUGH FRIDAY/
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
THROUGH TODAY...VFR WITH SCATTERED TO BROKEN MID LEVEL CLOUDS
BETWEEN 4000 AND 6000 FT AGL. WESTERLY WINDS GUSTING NEAR 40KT
ESPECIALLY EARLY IN THE DAY.
TONIGHT...VFR. WESTERLY WINDS GRADUALLY DIMINISHING.
OUTLOOK...
TUESDAY...VFR.
WEDNESDAY THROUGH THURSDAY...SUB-VFR LIKELY IN SN. IMPROVING
CONDITIONS THURSDAY AFTERNOON.
THURSDAY NIGHT THROUGH FRIDAY...VFR.
MARINE
A STRONG COLD FRONT BLASTED ITS WAY ACROSS THE WATERS LAST
EVENING WITH WIDESPREAD REPORTS OF 50 KT GUSTS. WINDS LIKELY
SLACK OFF A BIT BUT MAY INCREASE AT TIMES OVERNIGHT INTO MONDAY
AS COLD ADVECTION CONTINUES TO PROMOTE GOOD MIXING, SO WILL
MAINTAIN INHERITED TIME FRAME FOR THE TIME BEING. ONCE ITS MORE
CLEAR THAT WE WON'T SEE ANY FURTHER 50 KT GUSTS, A GALE WARNING
WILL BE NEEDED LATER MONDAY. SEAS 6-12 FEET TONIGHT INTO MONDAY.
LOW WATER IS POSSIBLE NEAR THE TIMES OF LOW TIDE BEGINNING
TONIGHT THROUGH TUESDAY.
OUTLOOK...
MONDAY NIGHT THROUGH TUESDAY NIGHT...LINGERING GALES POSSIBLE
MONDAY NIGHT, OTHERWISE, SCA CONDITIONS. THERE IS A CHANCE FOR
FREEZING SPRAY DUE TO THE STRONG WINDS AND COLD AIR TEMPERATURES
SPREADING OVER THE WATERS.
WEDNESDAY THROUGH WEDNESDAY NIGHT...SUB-SCA CONDITIONS. VSBY
RESTRICTIONS IN SN STARTING WEDENSDAY AFTERNOON.
THURSDAY THROUGH THURSDAY NIGHT...SCA CONDITIONS. VSBY
RESTRICTIONS IN SN THROUGH THURSDAY AFTERNOON.
FRIDAY...LINGERING SCA CONDITIONS POSSIBLE INTO FRIDAY
AFTERNOON.
PHI WATCHES/WARNINGS/ADVISORIES
PA...HIGH WIND WARNING UNTIL 6 PM EST THIS EVENING FOR PAZ054-055-
060>062-070-071-101>106.
NJ...HIGH WIND WARNING UNTIL 6 PM EST THIS EVENING FOR NJZ001-
007>010-012>027.
DE...HIGH WIND WARNING UNTIL 6 PM EST THIS EVENING FOR DEZ001>004.
MD...HIGH WIND WARNING UNTIL 6 PM EST THIS EVENING FOR MDZ012-015-
019-020.
MARINE...STORM WARNING UNTIL 6 AM EST EARLY THIS MORNING FOR ANZ430-431-
450>455.
LOW WATER ADVISORY UNTIL 8 AM EST THIS MORNING FOR ANZ450.
SYNOPSIS...MPS
NEAR TERM...FITZSIMMONS/JOHNSON/RCM
SHORT TERM...MPS
LONG TERM...MPS
AVIATION...JOHNSON/MPS
MARINE...FITZSIMMONS/MPS/RCM
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