089
FXUS61 KPHI 091036
AFDPHI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
636 AM EDT SAT MAY 9 2026
WHAT HAS CHANGED
NO SIGNIFICANT CHANGES.
KEY MESSAGES
1. WIDESPREAD SHOWERS AND A FEW STORMS ARE EXPECTED TODAY. THERE IS
A LOW RISK THAT A FEW STORMS COULD BE STRONG TO SEVERE.
2. SEVERAL OPPORTUNITIES FOR MUCH NEEDED RAINFALL FROM LATE SUNDAY
THROUGH NEXT WEEK.
DISCUSSION
KEY MESSAGE 1...WIDESPREAD SHOWERS AND A FEW STORMS ARE EXPECTED
TODAY. THERE IS A LOW RISK THAT A FEW STORMS COULD BE STRONG TO
SEVERE.
LARGE SCALE TROUGHING IS IN PLACE ACROSS MUCH OF THE EASTERN
CONUS THIS MORNING, WITH A SHORTWAVE AXIS CURRENTLY CENTERED
ACROSS THE OHIO VALLEY REGION. THIS SHORTWAVE WILL PIVOT
EASTWARD TODAY TOWARDS OUR REGION. AS IT DOES SO, A DIFFUSE WARM
FRONT WILL LIFT THROUGH THE AREA LATE THIS MORNING INTO THIS
AFTERNOON. AS THESE FEATURES APPROACH THE REGION, A BROAD AREA
OF ASCENT WILL LEAD TO WIDESPREAD SHOWERS TRAVERSING MUCH OF THE
REGION FROM LATE MORNING INTO THIS AFTERNOON. MUCH OF THIS
ACTIVITY IS EXPECTED TO BE CONFINED TO EASTERN PA AND NORTHERN
NJ WHERE THE BEST FORCING WILL BE LOCATED. WIDESPREAD CLOUDS AND
SHOWERS WILL KEEP TEMPERATURES IN THIS REGION IN THE UPPER 50S
TO LOWER 60S HERE.
FARTHER SOUTH WHERE FORCING WILL BE A BIT WEAKER, SCATTERED
SHOWERS AND A FEW THUNDERSTORMS STILL APPEAR LIKELY TO DEVELOP.
WIDESPREAD CLOUD COVER IS EXPECTED TO LIMIT THE DEGREE OF
HEATING, WITH TEMPERATURES ONLY CLIMBING INTO THE UPPER 60S TO
LOWER 70S. WITH THIS BEING SAID, COOL TEMPERATURES ALOFT WILL
ALLOW SOME DESTABILIZATION TO OCCUR. MLCAPE VALUES ARE EXPECTED
TO GENERALLY BE IN THE 250-500 J/KG RANGE ACROSS FAR
SOUTHEASTERN PA, SOUTHERN NJ,AND THE DELMARVA. WINDS ALOFT WILL
BE FAIRLY STRONG, LEADING TO 0-6 KM SHEAR VALUES AROUND 40-45
KT. GIVEN THE MEAGER INSTABILITY, THE SEVERE THREAT DOES APPEAR
TO BE FAIRLY LIMITED. HOWEVER, A FEW SEVERE STORMS CANNOT BE
ENTIRELY RULED OUT WITH MARGINALLY SEVERE HAIL AND WINDS
POSSIBLE IN THE STRONGEST STORMS. THIS APPEARS MOST LIKELY IN
THE MID TO LATE AFTERNOON. GIVEN THIS POTENTIAL, THE SPC HAS
PLACED ROUGHLY THE SOUTHERN HALF OF THE FORECAST AREA IN A
MARGINAL RISK (1/5) FOR SEVERE STORMS THIS AFTERNOON.
ALL-TOLD, QPF FROM THIS EVENT LOOKS FAIRLY LIGHT, GENERALLY
RANGING FROM 0.1-0.25", THOUGH HIGHER AMOUNTS WILL BE POSSIBLE
IN ANY THUNDERSTORMS. SHOWERS AND STORMS LOOK TO EXIT THE AREA
THIS EVENING. WITH LIGHT WINDS TONIGHT AND SOME RESIDUAL GROUND
MOISTURE, THE DEVELOPMENT OF SOME PATCHY FOG IS POSSIBLE. WE
WILL CONTINUE TO MONITOR THIS POTENTIAL. LOWS TONIGHT ARE
EXPECTED TO RANGE FROM THE UPPER 40S TO MID 50S.
KEY MESSAGE 2...SEVERAL OPPORTUNITIES FOR MUCH NEEDED RAINFALL FROM
LATE SUNDAY THROUGH NEXT WEEK.
AN UPPER-LEVEL TROUGH IS FORECAST TO DOMINATE ACROSS MUCH OF THE
EAST TO END THIS WEEKEND AND RIGHT THROUGH NEXT WEEK. SOME GUIDANCE
IS MUCH MORE POTENT WITH THE TROUGH AMPLIFICATION LATER NEXT WEEK
WITH A CLOSED LOW DEVELOPING IN THE VICINITY OF THE MID-ATLANTIC.
THESE TROUGHS WILL DRIVE A FEW COLD FRONTS ACROSS OUR AREA, WITH THE
FIRST ONE CROSSING OUR AREA SUNDAY NIGHT INTO MONDAY. THE GREATEST
FORCING WITH THE COLD FRONT LOOKS TO OCCUR FROM THE I-95 CORRIDOR
AND TO THE SOUTH AND EAST SUNDAY AFTERNOON AND ESPECIALLY SUNDAY
NIGHT THROUGH MONDAY MORNING. THIS MAY ALSO OVERLAP FOR A TIME WHEN
SOME SUFFICIENT INSTABILITY IS PRESENT FOR AT LEAST ISOLATED
THUNDERSTORMS. THE FRONT MAY BE SLOW TO SETTLE SOUTH AND EAST LATER
SUNDAY NIGHT INTO MONDAY MORNING AS THE INCOMING MAIN TROUGH AXIS IS
DISPLACED WELL TO OUR NORTHWEST. A MUCH WARMER SUNDAY WILL GIVE WAY
TO A MUCH COOLER MONDAY IN THE WAKE OF THE FRONT.
THE ACTIVE PATTERN LOOKS TO RELOAD AS ANOTHER UPPER-LEVEL TROUGH
QUICKLY REPLACES THE FIRST ONE ACROSS MUCH OF THE EAST. THIS FEATURE
MAY BECOME CLOSED OFF IN THE VICINITY OF THE MID-ATLANTIC WEDNESDAY
THROUGH FRIDAY. THIS INITIAL ARRIVAL OF WARM AIR ADVECTION AHEAD OF
THIS SYSTEM SHOULD DRIVE AN INCREASE IN SHOWER ACTIVITY DURING
WEDNESDAY. THE CHANCE FOR THUNDER IS LESS CERTAIN AT THIS TIME FRAME
AS IT WILL DEPEND ON HOW MUCH DESTABILIZATION CAN OCCUR. IF THE
SYSTEM CLOSES OFF AS IT ARRIVES THURSDAY INTO FRIDAY, THEN SURFACE
LOW PRESSURE MAY END UP DEVELOPING OFF THE NORTHERN MID-ATLANTIC
COAST. THIS WOULD INCREASE THE INTENSITY AND COVERAGE OF
SHOWERS/RAIN AND RESULT IN A STRONGER ONSHORE FLOW AND THEREFORE
EVEN COOLER TEMPERATURES. THIS WOULD ALSO TEND TO RESULT IN A MORE
STABLE AIR MASS AND THUS LITTLE TO NO RISK OF THUNDER. THE UPPER AIR
PATTERN EVOLVING DURING THE SECOND HALF OF NEXT WEEK IS LESS
CERTAIN, AS THE AMOUNT AND COVERAGE OF PRECIPITATION WILL DEPEND ON
WHETHER WE END UP WITH A CLOSED LOW OR JUST A SHARPER UPPER-LEVEL
TROUGH THAT QUICKLY PIVOTS THROUGH.
AVIATION /12Z SATURDAY THROUGH WEDNESDAY/
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS...
TODAY...PREVAILING VFR. WIDESPREAD LIGHT SHOWERS ARE EXPECTED
TO BEGIN MOVING INTO THE TERMINALS AS EARLY AS 14-16Z FROM WEST
TO EAST. A FEW STORMS ARE POSSIBLE AFTER AROUND 18Z, PRIMARILY
FOR THE I-95 TERMINALS, MIV, AND ACY. MVFR OR LOWER VISIBILITIES
ARE POSSIBLE IN ANY HEAVIER SHOWERS OR STORMS. SOUTH-SOUTHWEST
WINDS 10-15 KT, WITH SOME GUSTS AROUND 20 KT. MODERATE
CONFIDENCE.
TONIGHT...VFR EARLY AS SHOWERS AND A FEW STORMS CLEAR ALL
TERMINALS. WINDS QUICKLY DIMINISHING TO LIGHT AND VARIABLE BY
01-03Z WITH CALM PERIODS LIKELY OVERNIGHT. SOME LOW STRATUS OR
FOG IS POSSIBLE AT ALL TERMINALS, WHICH COULD LEAD TO MVFR OR
IFR CEILINGS AND VISIBILITIES. HAVE ONLY INCLUDED BR IN THE MIV
AND ACY TAFS WHERE CONFIDENCE IN OCCURRENCE IS THE HIGHEST.
MODERATE CONFIDENCE OVERALL, LOW CONFIDENCE IN THE EXTENT OF
RESTRICTIONS FROM LOW STRATUS OR FOG.
OUTLOOK...
SUNDAY AND MONDAY...A PERIOD OF SUB-VFR CONDITIONS PROBABLE LATER
SUNDAY AFTERNOON INTO MONDAY MORNING WITH SHOWERS. A FEW
THUNDERSTORMS POSSIBLE SUNDAY AFTERNOON INTO EARLY SUNDAY EVENING.
CONDITIONS SHOULD IMPROVE DURING MONDAY.
TUESDAY...VFR.
WEDNESDAY...SUB-VFR CONDITIONS POSSIBLE ALONG WITH SHOWERS.
MARINE
A SMALL CRAFT ADVISORY IS CURRENTLY IN EFFECT FOR ALL ATLANTIC
COASTAL WATERS FROM MANASQUAN INLET SOUTHWARD, AS WELL AS THE
LOWER DELAWARE BAY. BEGINNING AT 10 AM, THE ADVISORY WILL BE IN
EFFECT FOR ALL NJ AND DE ATLANTIC COASTAL WATERS AND THE LOWER
DELAWARE BAY AND CONTINUE THROUGH 12 AM SUNDAY. SOUTH WINDS
10-15 KT EARLY THIS MORNING WILL INCREASE TO 15-20 KT WITH GUSTS
AROUND 25 KT LATE THIS MORNING INTO THIS AFTERNOON. SEAS ARE
EXPECTED TO BE 3-5 FEET. IN ADDITION, SHOWERS AND A FEW STORMS
COULD CONTRIBUTE TO HAZARDOUS MARINE CONDITIONS. OVERNIGHT,
WINDS AND SEAS ARE EXPECTED TO SUBSIDE BELOW SCA LEVELS.
OUTLOOK...
SUNDAY...THE CONDITIONS ARE ANTICIPATED TO BE BELOW SMALL CRAFT
ADVISORY CRITERIA.
MONDAY...A BRIEF PERIOD OF SMALL CRAFT ADVISORY CONDITIONS POSSIBLE.
TUESDAY...THE CONDITIONS ARE ANTICIPATED TO BE BELOW SMALL CRAFT
ADVISORY CRITERIA.
WEDNESDAY...A PERIOD OF SMALL CRAFT ADVISORY CONDITIONS
POSSIBLE.
PHI WATCHES/WARNINGS/ADVISORIES
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR ANZ431-
451>455.
SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO MIDNIGHT EDT
TONIGHT FOR ANZ450.
DISCUSSION...COOPER/GORSE
AVIATION...COOPER/GORSE
MARINE...COOPER/GORSE
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