193
FXUS61 KPHI 200554
AFDPHI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
154 AM EDT MON APR 20 2026
WHAT HAS CHANGED
THE AVIATION SECTION HAS BEEN UPDATED.
KEY MESSAGES
1. BELOW NORMAL TEMPERATURES TAKE HOLD AFTER A STRONG COLD FRONT
MOVES THROUGH. FROST AND FREEZE PRODUCTS ARE IN PLACE FOR THE
NEXT TWO NIGHTS, WITH MONDAY NIGHT/TUESDAY MORNING BEING THE
COLDEST PART OF THE STRETCH. A RETURN TO ABOVE AVERAGE
TEMPERATURES THEN OCCURS LATER THIS WEEK.
2. MINOR TIDAL FLOODING (ADVISORY LEVEL) ALONG THE LOWER
DELAWARE BAY LATE TONIGHT INTO EARLY MONDAY MORNING.
DISCUSSION
KEY MESSAGE 1...BELOW NORMAL TEMPERATURES TAKE HOLD AFTER A
STRONG COLD FRONT MOVES THROUGH. FROST AND FREEZE PRODUCTS ARE
IN PLACE FOR THE NEXT TWO NIGHTS, WITH MONDAY NIGHT/TUESDAY
MORNING BEING THE COLDEST PART OF THE STRETCH. A RETURN TO ABOVE
AVERAGE TEMPERATURES THEN OCCURS LATER THIS WEEK.
COLD AIR WORKS IN TONIGHT BEHIND A COLD FRONT. INITIALLY, SKIES
WILL BE CLEAR AND WINDS QUICKLY FALLING OFF, RESULTING IN
TEMPERATURES DROPPING QUICKLY. INCREASING CLOUD COVER AS THE
NIGHT GOES ON WILL PREVENT THE BOTTOM FROM FALLING OUT, THOUGH
TEMPERATURES ARE LIKELY TO DROP INTO THE 30S. SOME SPOTS EVEN
SHOULD FALL BELOW FREEZING, MAINLY IN THE POCONOS AND
NORTHWESTERN NJ. IN FACT, SUSSEX COUNTY, NJ WAS ADDED TO THE
FREEZE WARNING FOR TONIGHT, JOINING CARBON AND MONROE COUNTY IN
PA.
WITH SOME MOISTURE AT THE SURFACE WITH SUNDAY'S RAINFALL AND
TEMPERATURES DROPPING INTO THE 34 TO 36 DEGREE RANGE, SOME FROST
IS POSSIBLE OUTSIDE OF THE FREEZE WARNING. A FROST ADVISORY WAS
ISSUED FOR INTERIOR NORTHERN NJ (WARREN/MORRIS/HUNTERDON/SOMERSET)
AND NORTHAMPTON COUNTY IN PA.
AFTER AN UNEVENTFUL MONDAY DAY PERIOD, HIGH PRESSURE WILL THEN
SLIDE OVER OUR REGION ON MONDAY NIGHT BEFORE GRADUALLY SHIFTING
OFFSHORE DURING TUESDAY. THIS COMBINED WITH A CLEARING SKY,
WINDS BECOMING VERY LIGHT TO CALM AND LOW DEW POINTS WILL RESULT
IN EFFICIENT RADIATIONAL COOLING CONDITIONS MONDAY NIGHT. A
WIDESPREAD FREEZE LOOKS TO OCCUR EARLY TUESDAY MORNING, AND THE
FREEZE WATCH REMAINS IN PLACE EXCEPT FOR THE IMMEDIATE COAST.
ALL OF OUR COUNTIES NOW HAVE AN ACTIVE GROWING SEASON DUE TO THE
RECENT EXCESSIVE WARMTH. BLOOMS/VEGETATION HAVE QUICKLY
INITIATED AND IN SOME CASES ARE AHEAD OF SCHEDULE. FRUIT TREES
AND OTHER COLD SENSITIVE PLANTS ALREADY PLANTED ARE THE MOST
CONCERN. FROST FORMATION MIGHT BE SOMEWHAT LIMITED GIVEN A MUCH
DRIER LOW-LEVEL AIR MASS IN PLACE. OUTSIDE OF THE URBAN CITY
CENTERS AND AWAY FROM THE IMMEDIATE COAST, TEMPERATURES ARE
EXPECTED TO DROP BELOW FREEZING. IN SOME CASES, WELL BELOW
FREEZING AND INTO THE LOW 20S.
HIGH TEMPERATURES BOTH MONDAY AND TUESDAY ARE FORECAST TO BE IN THE
40S AND 50S ACROSS THE REGION, WHICH IS SEVERAL DEGREES BELOW
AVERAGE. A FEW LIGHT RAIN/SNOW OR GRAUPEL SHOWERS ARE POSSIBLE ON
MONDAY AS THE CORE OF THE COLD AIR ALOFT IS OVERHEAD ALONG WITH SOME
MID LEVEL ENERGY SLIDING THROUGH WITH THE TROUGH AXIS. THE AIR MASS
BELOW CLOUD BASE LOOKS RATHER DRY AND THEREFORE ANYTHING THAT
DEVELOPS COULD BE MOSTLY VIRGA OUTSIDE OF THE HIGHER TERRAIN. IT
WILL FEEL MUCH COLDER MONDAY WITH A BREEZE AND THE VERY DRY AIR IN
PLACE. A RETURN, SOUTHERLY, FLOW WILL THEN BECOME ESTABLISHED
TUESDAY AND CONTINUE INTO WEDNESDAY. THIS ALONG WITH AN INCREASE IN
WARM AIR ADVECTION AND RISING HEIGHTS WILL RESULT IN TEMPERATURES
CLIMBING BACK ABOVE AVERAGE WEDNESDAY THROUGH SATURDAY.
KEY MESSAGE 2...MINOR TIDAL FLOODING (ADVISORY LEVEL) ALONG THE
LOWER DELAWARE BAY LATE TONIGHT INTO EARLY MONDAY MORNING.
A COASTAL FLOOD ADVISORY HAS BEEN ISSUED FOR THE LOWER DELAWARE
BAY FOR MINOR TIDAL FLOODING. WHILE WINDS HAVE SHIFTED OFFSHORE
INTO TONIGHT, WATER LEVELS REMAIN ELEVATED. BEING NOW TWO DAYS
REMOVED FROM A NEW MOON AND A DEPARTING STORM SYSTEM, NO
ADDITIONAL ADVISORY LEVEL COASTAL FLOODING IS EXPECTED AFTER
TONIGHT'S MINOR TIDAL FLOODING ENDS EARLY THIS MORNING.
AVIATION /06Z MONDAY THROUGH FRIDAY/
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
REST OF TONIGHT...MAINLY VFR CONDITIONS. WESTERLY WINDS AROUND
5 KNOTS OR LESS WITH PERIODS OF LIGHT AND VARIABLE WINDS. SCT TO
BKN CEILINGS MOVE IN FROM WEST TO EAST THROUGH 12Z. HIGH
CONFIDENCE.
MONDAY...VFR. A FEW LIGHT/BRIEF SHOWERS OR SPRINKLES POSSIBLE DURING
THE DAY. BKN CEILINGS AROUND 5000-6000 FEET. WEST-NORTHWEST
WIND GUSTING TO AROUND 20 KNOTS DURING THE AFTERNOON. HIGH
CONFIDENCE.
MONDAY NIGHT...VFR. A NORTH WIND AROUND 5 KNOTS. HIGH
CONFIDENCE.
OUTLOOK...
TUESDAY THROUGH TUESDAY NIGHT...VFR. NO SIGNIFICANT WEATHER.
WEDNESDAY...MVFR/IFR CONDITIONS POSSIBLE WITH SOME SHOWERS AND
LOW CLOUDS AROUND.
WEDNESDAY NIGHT THROUGH FRIDAY...VFR. NO SIGNIFICANT WEATHER.
MARINE
AFTER A TRANQUIL OVERNIGHT PERIOD, WINDS PICK BACK UP FOR
MONDAY. GUSTS COULD GET NEAR 25 KT AT TIMES, MAINLY FOR DELAWARE
BAY AND ADJACENT OCEAN ZONES. A SMALL CRAFT ADVISORY MAY BE
NEEDED FOR THESE AREAS.
SEAS OF 2 TO 4 FEET EXPECTED THROUGH THE PERIOD.
OUTLOOK...
MONDAY NIGHT THROUGH FRIDAY...NO MARINE HEADLINES EXPECTED.
PHI WATCHES/WARNINGS/ADVISORIES
PA...FREEZE WATCH FROM LATE TONIGHT THROUGH TUESDAY MORNING FOR
PAZ054-055-060>062-070-071-101>106.
FREEZE WARNING UNTIL 10 AM EDT THIS MORNING FOR PAZ054-055.
FROST ADVISORY UNTIL 8 AM EDT THIS MORNING FOR PAZ062.
NJ...FREEZE WATCH FROM LATE TONIGHT THROUGH TUESDAY MORNING FOR
NJZ001-007>010-012-013-015>023-027.
COASTAL FLOOD ADVISORY UNTIL 3 AM EDT EARLY THIS MORNING FOR
NJZ021>025.
FREEZE WARNING UNTIL 10 AM EDT THIS MORNING FOR NJZ001.
FROST ADVISORY UNTIL 8 AM EDT THIS MORNING FOR NJZ007>010.
DE...FREEZE WATCH FROM LATE TONIGHT THROUGH TUESDAY MORNING FOR
DEZ001>003.
COASTAL FLOOD ADVISORY UNTIL 3 AM EDT EARLY THIS MORNING FOR
DEZ002>004.
MD...FREEZE WATCH FROM LATE TONIGHT THROUGH TUESDAY MORNING FOR
MDZ012-015-019-020.
MARINE...NONE.
DISCUSSION...GORSE/HOEFLICH/MJL
AVIATION...GUZZO/HOEFLICH
MARINE...AKL/HOEFLICH
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