372
FXUS61 KPHI 281131
AFDPHI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
731 AM EDT TUE APR 28 2026
WHAT HAS CHANGED
NO SIGNIFICANT CHANGES.
KEY MESSAGES
1. A ROUND OF MUCH NEEDED RAIN LATER WEDNESDAY INTO EARLY
THURSDAY. LOW RISK OF A STRONGER THUNDERSTORM FOR (MOSTLY)
DELMARVA.
DISCUSSION
KEY MESSAGE 1...A ROUND OF MUCH NEEDED RAIN LATER WEDNESDAY INTO
EARLY THURSDAY. LOW RISK OF A STRONGER THUNDERSTORM FOR (MOSTLY)
DELMARVA.
A STRONG UPPER-LEVEL TROUGH/CLOSED LOW CENTERED OVER OR JUST NORTH
OF THE UPPER GREAT LAKES WEDNESDAY NIGHT AND THURSDAY WILL GRADUALLY
PIVOT EASTWARD. THIS WILL DRIVE A STRONG COLD FRONT ACROSS OUR
AREA EARLY THURSDAY AS LOW PRESSURE DEVELOPS ALONG THE COLD FRONT.
AS OF NOW, THIS SURFACE LOW LOOKS TO TRACK ACROSS THE SOUTHERN
HALF OF OUR OUR REGION EARLY THURSDAY MORNING.
THE PRECIPITABLE WATER VALUES ARE FORECAST TO SURGE ACROSS OUR AREA
AHEAD OF THE COLD FRONT TO 1.00-1.50 INCHES. A LOW-LEVEL JET AROUND
850 MB OF 40 TO 45 KNOTS IS FORECAST TO ARRIVE WEDNESDAY EVENING.
THIS WILL INCREASE THE LOW-LEVEL WARM AIR ADVECTION AND SUBSEQUENTLY
AUGMENT THE FORCING FOR ASCENT AHEAD OF AND WITH AN INCOMING
COLD FRONT. AN AREA OF LOW PRESSURE IS ALSO FORECAST TO DEVELOP
ALONG THE FRONT IN THE VICINITY OF DELMARVA. THIS WILL ALL RESULT
IN AN EXPANDING AREA OF SHOWERS, OR A PERIOD OF RAIN, TO ARRIVE
FROM THE WEST LATER WEDNESDAY AFTERNOON WITH THE BULK OF THE
RAINFALL OCCURRING WEDNESDAY NIGHT INTO EARLY THURSDAY MORNING.
SOME EMBEDDED DOWNPOURS ARE POSSIBLE GIVEN THE HIGHER PRECIPITABLE
WATER VALUES AND STRONGER FORCING, HOWEVER THE OVERALL INSTABILITY
LOOKS TO BE RATHER WEAK. WHILE SOME THUNDER (LOW- TOPPED) CANNOT
BE RULED OUT, THE RISK OF A FEW STRONGER THUNDERSTORMS LOOKS
RATHER LOW AT THIS TIME WITH THE ANTICIPATION OF CLOUD COVER
LIMITING THE INSTABILITY. IF MORE INSTABILITY HOWEVER CAN BECOME
REALIZED, THEN GIVEN THE SHEAR MAGNITUDE THERE WOULD BE SOME
SEVERE THUNDERSTORM RISK ESPECIALLY ACROSS OUR DELMARVA ZONES
LATER WEDNESDAY AFTERNOON AND EARLY WEDNESDAY EVENING.
OVERALL, STORM TOTAL RAINFALL LOOK TO BE BETWEEN 0.50-1.00
INCHES ACROSS OUR ENTIRE REGION. THE OVERNIGHT AVERAGE IS
PERHAPS A LITTLE LESS THAN MONDAY'S FORECAST, BUT NOT BY MUCH.
IF AN EMBEDDED STRONGER CONVECTIVE CONTRIBUTION MATERIALIZES,
THEN LOCALLY HIGHER RAINFALL TOTALS WILL BE POSSIBLE. THIS RAIN
IS MUCH NEEDED GIVEN THE ONGOING LONGER TERM DROUGHT CONDITIONS
IN PLACE. THE SHOWERS/RAIN RAPIDLY END EARLY THURSDAY MORNING AS
THE COLD FRONT AND SURFACE LOW CLEARS OUR AREA.
AVIATION /12Z TUESDAY THROUGH SATURDAY/
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
TODAY...VFR WITH CLOUDS INCREASING AND BASES LOWERING THROUGH
THE DAY. LIGHT AND VARIABLE TO CALM WINDS, BECOMING SOUTH-
SOUTHEAST 5-10 KNOTS. PERHAPS A LIGHT SHOWER THIS AFTERNOON FOR
KRDG/KABE; NO IMPACTS EXPECTED. MODERATE CONFIDENCE.
TONIGHT...VFR CEILINGS. SOUTH-SOUTHEAST WINDS NEAR 5 KNOTS OR
LIGHT AND VARIABLE. MODERATE CONFIDENCE.
OUTLOOK...
WEDNESDAY...VFR EARLY THEN LOWERING TO SUB-VFR CONDITIONS ALONG
WITH SHOWERS LATE IN THE AFTERNOON AND OVERNIGHT. THERE IS ALSO
A SLIGHT CHANCE FOR AN EVENING THUNDERSTORM.
THURSDAY...MOSTLY SUB-VFR WITH SOME SHOWERS POSSIBLE, MAINLY
EARLY, THEN VFR. NORTHWEST WIND GUSTS UP TO 20 KNOTS.
FRIDAY...MAINLY VFR. WEST-NORTHWEST WIND GUSTS TO 20 KNOTS DURING
THE DAY.
SATURDAY...A PERIOD OF SUB-VFR AND SHOWERS POSSIBLE ESPECIALLY
FOR THE DELAWARE VALLEY SITES AND S/E.
MARINE
SMALL CRAFT ADVISORY REMAINS IN EFFECT THROUGH TUESDAY DUE TO ELEVATED
SEAS NEAR 5 FEET. WINDS MOSTLY 10 KNOTS OR LESS. FAIR WEATHER.
OUTLOOK...
TUESDAY NIGHT...SEAS MAY LINGER AT 5 FEET FOR A TIME ON THE ALTANTIC
COASTAL ZONES.
WEDNESDAY AND THURSDAY...A PERIOD OF SMALL CRAFT ADVISORY CONDITIONS
POSSIBLE. SHOWERS LATER WEDNESDAY AND INTO THURSDAY MORNING. A
TSTM IS PASSABLE WED NIGHT.
FRIDAY AND SATURDAY...THE CONDITIONS SHOULD BE MOSTLY BELOW SMALL
CRAFT ADVISORY CRITERIA. SHOWERS POSSIBLE FRIDAY NIGHT AND SATURDAY.
PHI WATCHES/WARNINGS/ADVISORIES
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR
ANZ450>455.
DISCUSSION...GORSE/MJL/OHARA
AVIATION...GORSE/MJL/OHARA
MARINE...MJL/OHARA
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page