885
FXUS61 KPHI 200825
AFDPHI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
325 AM EST MON JAN 20 2025
SYNOPSIS
STRENGTHENING LOW PRESSURE MOVES INTO THE CANADIAN MARITIMES THROUGH
THIS MORNING. ARCTIC HIGH PRESSURE BUILDS INTO THE OHIO VALLEY LATER
TODAY, THEN EXTENDS INTO OUR AREA TUESDAY BEFORE SETTLING OVERHEAD
LATER WEDNESDAY. A SYSTEM TRACKS TO OUR SOUTH AND EAST TUESDAY NIGHT
AND WEDNESDAY WITH ANOTHER ONE THURSDAY NIGHT AND FRIDAY. HIGH
PRESSURE SLIDES ACROSS OUR AREA SATURDAY, THEN A COLD FRONT SHOULD
ARRIVE LATER SUNDAY.
NEAR TERM /THROUGH TONIGHT/
SKIES HAVE CLEARED OUT QUITE NICELY AND STRONG COLD AIR ADVECTION
HAS SET UP IN THE WAKE OF THE DEPARTING WINTER STORM. A PERIOD OF
BITTER COLD WILL BEGIN TODAY. WIND CHILLS ARE CURRENTLY IN THE
SINGLE DIGITS, WITH AREAS IN THE POCONOS DOWN BELOW ZERO, EVEN BELOW
-10 F. THE COLD WEATHER ADVISORY REMAINS IN PLACE FOR AREAS NORTH
AND WEST OF THE I-95 CORRIDOR.
BONE-CHILLING COLD IS EXPECTED TODAY AND TONIGHT AS AN ARCTIC
AIRMASS WORKS ITS WAY IN. 850 MB TEMPERATURES CONTINUE TO FALL THIS
MORNING AND WILL END UP AROUND BETWEEN -15 TO -20 C, RESULTING IN
THE COLDEST TEMPERATURES OF THE SEASON (ONLY TO BE OUTDONE BY
TEMPERATURES TUESDAY/TUESDAY NIGHT/WEDNESDAY-MORE ON THAT BELOW).
HIGHS WILL ONLY GET INTO THE LOW TO MID 20S WITH MID-TEENS IN THE
POCONOS. BRISK WINDS, A RESULT OF THE GRADIENT IN PLACE DUE TO THE
INCOMING HIGH AND DEPARTING SURFACE LOW, WILL ONLY MAKE IT FEEL
COLDER, WITH WIND CHILLS TODAY IN THE UPPER SINGLE DIGITS/LOWER
TEENS (MAY NOT MAKE IT ABOVE 0 IN THE POCONOS).
THE COLD WEATHER ADVISORY WILL BE EXPANDED TO INCLUDE THE ENTIRE
REGION TONIGHT. HIGH PRESSURE MOVES CLOSER, RESULTING IN GRADUALLY
DIMINISHING WINDS. LOWS WILL DROP INTO THE SINGLE DIGITS, WITH WIND
CHILLS FALLING BELOW ZERO FOR NEARLY ALL LOCATIONS AND BELOW -10 IN
THE HIGHER ELEVATIONS. KEEP ANY PETS INDOORS, AND IF YOU HAVE TO BE
OUTSIDE, WEAR MULTIPLE LAYERS.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/
BITTERLY COLD CONDITIONS ACROSS THE REGION. COLD WEATHER ADVISORY IN
EFFECT.
ARCTIC AIR FIRMLY ENTRECHED ACROSS THE REGION THROUGH WEDNESDAY
NIGHT. HIGH TEMPERATURES TUESDAY IN THE TEENS TO LOWER 20S, AND WITH
WINDS 10-15 MPH WITH WIND CHILL VALUES ONLY IMPROVING TO THE TEENS
AND SINGLE DIGITS. WHILE THE WIND WILL DIMINISH SOME TUESDAY NIGHT,
A BREEZE IS EXPECTED TO CONTINUE WITH BITTER COLD CONTINUING AS LOWS
RANGE FROM ZERO TO NEGATIVE 5F FOR THE POCONOS AND SINGLE DIGITS
ELSEWHERE (WIND CHILLS DROPPING TO ZERO AND BELOW ZERO). FOR
WEDNESDAY, HIGHS REACH THE TEENS FOR MOST AND WINDS ARE GENERALLY
AROUND 10 MPH WHICH LEADS TO WIND CHILLS BELOW ZERO FOR ALL AREAS TO
START WEDNESDAY MORNING. GIVEN THE EXTENDED STRETCH OF BITTERLY COLD
CONDITIONS (CUMULATIVE IMPACTS) AND THAT TUESDAY MORNING, TUESDAY
NIGHT AND WEDNESDAY MORNING HIT THE CRITERIA FOR MANY AREAS, OPTED
TO KEEP THE MESSAGING SIMPLE AND EXTEND THE COLD WEATHER ADVISORY
FOR THE ENTIRE AREA THROUGH NOON ON WEDNESDAY.
AS FOR THE WEATHER FEATURES DURING THIS TIME PERIOD, WE HAVE AN
ARCTIC HIGH PRESSURE SYSTEM BUILDING IN THROUGH TUESDAY. MEANWHILE,
AT THE UPPER-LEVELS, A TROUGH MOVES INTO THE REGION FROM TUESDAY
INTO WEDNESDAY MORNING. NOW THIS TROUGH WILL MAKE THINGS A LITTLE
INTERESTING BECAUSE THERE IS A PIECE OF ENERGY ROTATING THROUGH
TUESDAY NIGHT INTO WEDNESDAY MORNING. AT THE SURFACE, THERE IS A LOW
PRESSURE SYSTEM WHICH MOST MODELS KEEP OFFSHORE WITH NO
PRECIPITATION REACHING OUR AREA. RIGHT NOW, ONLY PART OF THE AREA
HAS SOME MAINLY SLIGHT CHANCE POPS FOR SNOW. THE MODELS THAT KEEP
THE PRECIPITATION OFFSHORE HAVE A STRONGER HIGH IN PLACE WHILE THE
ONES THAT SHOW SOME PRECIPITATION REACHING INTO PORTIONS OF THE
COASTAL PLAIN SHOW WEAKNESS IN THE HIGH ALLOWING THE PRECIPITATION
SHIELD TO EXTEND FARTHER NORTHWEST FROM THE SURFACE LOW. HIGH
PRESSURE IS THE MAIN WEATHER FEATURE FOR WEDNESDAY AND KEEPS THINGS
QUIET BUT VERY COLD WITH WEAK UPPER-LEVEL RIDGING.
LONG TERM /THURSDAY THROUGH SUNDAY/
TEMPERATURES START TO IMPROVE THURSDAY AND IT CONTINUES INTO THE
WEEKEND.
AFTER A VERY COLD FIRST HALF OF THE WEEK, TEMPERATURES START TO
IMPROVE IN THE LONG TERM. HIGHS ON THURSDAY ARE IN THE UPPER
TEENS TO UPPER 20S ACROSS THE AREA. FOLLOWING THURSDAY, EACH DAY
BUILDS UPON THE PREVIOUS DAY IN TERMS OF HIGH TEMPERATURES.
FOR THE WEATHER FEATURES, THERE IS STILL HIGH PRESSURE HAVING
ITS INFLUENCE ON OUR REGION. UPPER-LEVEL TROUGHING IS MOVING
INTO THE REGION THURSDAY THROUGH FRIDAY NIGHT AND ANOTHER PIECE
OF ENERGY IS HINTED TO ROTATE THROUGH. ONCE AGAIN, THIS WOULD BE
IN THE FORM OF A LOW PRESSURE SYSTEM. THERE IS STILL A LARGE
AMOUNT OF UNCERTAINTY GIVEN THIS BEING IN THE LONG TERM. MODEL
GUIDANCE SHOWS THE POTENTIAL FOR SOME SNOW TO BRUSH PARTS OF OUR
AREA THURSDAY INTO FRIDAY MORNING. GIVEN THE UNCERTAINTY,
SLIGHT CHANCE TO CHANCE POPS WERE THE EXTENT FOR ANY
PRECIPITATION DURING THAT TIME PERIOD. FOR THE WEEKEND, SATURDAY
LOOKS DRY WITH SOME RAIN/SNOW SHOWERS BY LATER SUNDAY (KEPT ANY
POPS AT SLIGHT CHANCE FOR NOW).
AVIATION /08Z MONDAY THROUGH FRIDAY/
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS...
THROUGH 12Z...VFR/SKC. NORTHWEST WINDS AROUND 10 KT WITH OCCASIONAL
GUSTS UP TO 20 KT. HIGH CONFIDENCE.
MONDAY...PRIMARILY VFR CONDITIONS. HOWEVER, AREAS OF BLOWING SNOW
ARE POSSIBLE NEAR KABE AND KRDG, WHICH MAY RESULT IN PERIODS OF MVFR
VISIBILITY. HAVE LOW CONFIDENCE ON THE DURATION OR EXTENT OF BLSN,
BUT THERE IS ENOUGH OF A RISK TO INCLUDE A MENTION IN BOTH TAFS.
WEST-NORTHWEST WINDS 10-15 KNOTS WITH GUSTS 20-30 KNOTS. MODERATE
CONFIDENCE OVERALL.
MONDAY NIGHT...VFR. WEST/NORTHWEST WINDS GRADUALLY DIMINISHING TO
AROUND 5-10 KT. HIGH CONFIDENCE.
OUTLOOK...
TUESDAY...VFR WITH INCREASING CLOUDS, AS A SYSTEM TRACKS WELL TO OUR
SOUTH AND EAST AT NIGHT. WEST-NORTHWEST WINDS 10-15 KNOTS,
DIMINISHING SOME AT NIGHT.
WEDNESDAY...VFR AS A SYSTEM SHOULD TRACK WELL TO OUR SOUTH AND EAST.
THURSDAY AND FRIDAY...VFR OVERALL. A SYSTEM LOOKS TO START FAR
ENOUGH TO OUR SOUTH AND EAST.
MARINE
THE GALE WARNING WAS CANCELLED FOR COASTAL WATERS NORTH OF LITTLE
EGG INLET AND UPPER DELAWARE BAY. A SMALL CRAFT ADVISORY REPLACES
THE GALE WARNING IN THESE ZONES, UNTIL 1 AM TUESDAY FOR
UPPER DELAWARE BAY, AND 6 AM TUESDAY FOR THE ANZ450-451.
GUSTS REMAIN HIGHER ON THE SOUTHERN WATERS AND LOWER DELAWARE BAY,
WITH THE GALE WARNING IN PLACE THROUGH 6 AM. ONCE THE GALE WARNING
COMES DOWN, AN SCA WILL REPLACE IT, AND WILL HAVE SIMILAR TIMING TO
THE SCA FURTHER NORTH (THROUGH TONIGHT).
STRONG WINDS, VERY COLD AIR, AND 4 TO 6 FOOT SEAS WILL BRING THE
POTENTIAL FOR FREEZING SPRAY. ANY MARINERS SHOULD TAKE CAUTION TO
PROTECT ANY EQUIPMENT. A FREEZING SPRAY ADVISORY IS IN EFFECT FOR
ALL MARINE ZONES.
OUTLOOK...
TUESDAY AND WEDNESDAY...A PERIOD OF SMALL CRAFT ADVISORY CONDITIONS
ARE POSSIBLE LATER TUESDAY NIGHT AND WEDNESDAY MORNING. FREEZING
SPRAY POSSIBLE AT TIMES.
THURSDAY AND FRIDAY...THE CONDITIONS OVERALL SHOULD BE BELOW
SMALL CRAFT ADVISORY CRITERIA.
PHI WATCHES/WARNINGS/ADVISORIES
PA...COLD WEATHER ADVISORY FROM 6 PM THIS EVENING TO NOON EST
WEDNESDAY FOR PAZ070-071-102-104-106.
COLD WEATHER ADVISORY UNTIL NOON EST WEDNESDAY FOR PAZ054-055-
060>062-101-103-105.
NJ...COLD WEATHER ADVISORY FROM 6 PM THIS EVENING TO NOON EST
WEDNESDAY FOR NJZ010-012>027.
COLD WEATHER ADVISORY UNTIL NOON EST WEDNESDAY FOR NJZ001-
007>009.
DE...COLD WEATHER ADVISORY FROM 6 PM THIS EVENING TO NOON EST
WEDNESDAY FOR DEZ001>004.
MD...COLD WEATHER ADVISORY FROM 6 PM THIS EVENING TO NOON EST
WEDNESDAY FOR MDZ012-015-019-020.
MARINE...SMALL CRAFT ADVISORY UNTIL 1 AM EST TUESDAY FOR ANZ430.
FREEZING SPRAY ADVISORY UNTIL 7 PM EST THIS EVENING FOR ANZ430-
431-450>455.
GALE WARNING UNTIL 6 AM EST EARLY THIS MORNING FOR ANZ431-
452>455.
SMALL CRAFT ADVISORY UNTIL 6 AM EST TUESDAY FOR ANZ450-451.
SYNOPSIS...GORSE/JOHNSON
NEAR TERM...HOEFLICH
SHORT TERM...GORSE/GUZZO
LONG TERM...GORSE/GUZZO
AVIATION...GORSE/HOEFLICH
MARINE...GORSE/HOEFLICH
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