952  
FXUS61 KPHI 200527  
AFDPHI  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ  
127 AM EDT SAT JUN 20 2026  
   
WHAT HAS CHANGED
 
 
AVIATION SECTION UPDATED FOR 6Z TAFS.  
 

 
   
KEY MESSAGES
 
 
1. A SYSTEM MOVES IN MONDAY BRINGING THE THREAT FOR HEAVY  
RAINFALL AND ASSOCIATED FLOODING ALONG WITH AT LEAST SOME RISK  
FOR SEVERE WEATHER.  
 

 
   
DISCUSSION
 
 
KEY MESSAGE 1...A SYSTEM MOVES IN MONDAY BRINGING THE THREAT FOR  
HEAVY RAINFALL AND ASSOCIATED FLOODING ALONG WITH AT LEAST SOME  
RISK FOR SEVERE WEATHER.  
 
MEDIUM RANGE GUIDANCE CONTINUES TO HINT AT A STRETCH OF UNSETTLED  
WEATHER TO START NEXT WEEK. THE MAIN QUESTION WILL BE THE TRACK OF  
THE LOW PRESSURE AS IT MOVES THROUGH THE REGION, WHICH WILL HAVE  
NOTABLE CONSEQUENCE IN SPECIFIC IMPACTS.  
 
THE MAIN TAKEAWAY THOUGH IS THAT MONDAY IS CURRENTLY LOOKING WET,  
WITH SOME THUNDERSTORMS LIKELY MIXED IN AS THE AREA OF LOW PRESSURE  
MOVES THROUGH, MAINLY IN THE AFTERNOON. CONSENSUS GUIDANCE SHOWS PWAT  
VALUES (1.75- 2.00") NEAR THE CLIMATOLOGICAL MAXIMA, SETTING UP THE  
RISK FOR HEAVY RAINFALL. NBM PROBABILITY OF 1" OR MORE FROM THIS  
SYSTEM HAS AROUND 30-50% FROM PHILADELPHIA ON NORTH AND AROUND  
A 10- 30% SOUTH OF PHILADELPHIA. THESE NUMBERS HAVE COME DOWN SOME  
SINCE THE PREVIOUS FORECAST CYCLE BUT IT'S WORTH STRESSING THE CONTINUING  
UNCERTAINTY IN THE FORECAST. IF THE LOW TRACK TRENDS FARTHER NORTH,  
THIS WOULD TEND TO REDUCE THE HEAVY RAINFALL AND FLASH FLOODING THREAT  
BUT INCREASE THE SEVERE WEATHER THREAT...ESPECIALLY OVER SOUTHERN  
PARTS OF OUR FORECAST AREA (DELMARVA, SOUTHERN NJ). IN FACT THIS  
COULD END UP BEING A SYSTEM THAT BRINGS MAINLY A HEAVY RAINFALL/  
FLOODING THREAT TO NORTHERN PARTS OF OUR FORECAST AREA WITH  
MORE OF A SEVERE THREAT TO SOUTHERN AREAS. AGAIN, A LOT OF  
UNCERTAINTY STILL REMAINS, BUT THE OVERARCHING SYNOPTIC SETUP  
WILL BE FAVORABLE FOR AN IMPACTFUL SYSTEM. ONE FINAL NOTE  
REGARDING THE FLOODING, WE'RE STILL IN A REGION-WIDE DROUGHT SO  
THAT COULD MITIGATE THE FLOOD THREAT SOME.  
 
SHOWERS/STORMS MAY LINGER INTO MONDAY EVENING BUT SHOULD BE CLEARED  
OF THE AREA BY TUESDAY MORNING AS A COLD FRONT SWEEPS OFFSHORE.  
 

 
   
AVIATION /06Z SATURDAY THROUGH WEDNESDAY/
 
 
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,  
KILG, KMIV, KACY AND SURROUNDING AREAS.  
 
THRU 12Z THIS MORNING...VFR. WEST-NORTHWEST WINDS LESS THAN 10  
KNOTS. HIGH CONFIDENCE.  
 
TODAY AND TONIGHT...MAINLY VFR. ISOLATED SHOWER NOT IMPOSSIBLE  
IN THE AFTERNOON/EVENING, BUT ODDS LESS THAN 25 PERCENT, EVEN  
LESS A CHANCE OF ANY RESTRICTIONS WITH SAID SHOWER. WEST-  
NORTHWEST WINDS INCREASING TO 10-15 KNOTS WITH GUSTS UP TO 25  
KNOTS IN THE AFTERNOON, THEN DIMINISHING AGAIN AFTER SUNSET.  
HIGH CONFIDENCE.  
 
OUTLOOK...  
 
SUNDAY...VFR. NO SIGNIFICANT WEATHER LIKELY.  
 
SUNDAY NIGHT...MAINLY VFR. SOME SHOWERS POSSIBLE LATE.  
 
MONDAY AND MONDAY NIGHT...SUB-VFR CONDITIONS WITH SHOWERS AND  
SOME THUNDERSTORMS LIKELY.  
 
TUESDAY AND WEDNESDAY...VFR. NO SIGNIFICANT WEATHER.  
 

 
   
MARINE
 
 
A WEAK TROUGH WILL TRAVERSE THE WATERS THIS EVENING AND WILL  
RESULT IN A PERIOD OF INCREASED WESTERLY WINDS OVERNIGHT AND  
SATURDAY MORNING. THE STRONGEST WIND GUSTS (25 KNOTS) LOOKS TO  
BE ACROSS THE NORTHERN TO CENTRAL NEW JERSEY ATLANTIC COASTAL  
WATERS, AND THIS IS WHERE A SMALL CRAFT ADVISORY HAS BEEN  
ISSUED/EXPANDED FOR LATE TONIGHT AND SATURDAY MORNING. SEAS ON  
THE OCEAN ARE FORECAST TO REMAIN BELOW 5 FEET HOWEVER.  
 
OUTLOOK...  
 
SATURDAY NIGHT THROUGH SUNDAY NIGHT...NO MARINE HEADLINES EXPECTED.  
 
MONDAY THROUGH MONDAY NIGHT...SCA CONDITIONS EXPECTED WITH  
SOUTHERLY WIND GUSTS INCREASING TO AROUND 30 KT WITH SEAS 4 TO  
7 FEET.  
 
TUESDAY...SCA CONDITIONS COULD LINGER EARLY.  
 
WEDNESDAY...SUB SCA CONDITIONS.  
 
RIP CURRENTS...  
 
FOR SATURDAY, WESTERLY WINDS AROUND 10-15 MPH ARE EXPECTED.  
HOWEVER, THE ONSHORE SWELLS BEGIN TO WEAKEN, DECREASING TO  
AROUND 2 TO 4 FEET AT AROUND A 7 SECOND PERIOD. BREAKING WAVES  
IN THE SURF ZONE SHOULD BE AROUND 2 FEET OR LESS AS A RESULT.  
THEREFORE, A LOW RISK FOR THE DEVELOPMENT OF DANGEROUS RIP  
CURRENTS IS FORECAST FOR ALL BEACHES ON SATURDAY.  
 
FOR SUNDAY, WESTERLY WINDS DIMINISH TO AROUND 10 MPH. ONSHORE  
SWELLS WILL REMAIN WEAK AROUND 1 TO 2 FEET WITH A 7 SECOND  
PERIOD. BREAKING WAVES IN THE SURF ZONE WILL BE AROUND 1 FOOT OR  
LESS. THEREFORE, A LOW RISK FOR THE DEVELOPMENT OF DANGEROUS RIP  
CURRENTS IS FORECAST FOR ALL BEACHES ON SUNDAY.  
 
FOR SPECIFIC BEACH FORECASTS, VISIT WEATHER.GOV/BEACH/PHI  
 

 
   
PHI WATCHES/WARNINGS/ADVISORIES
 
 
PA...NONE.  
NJ...NONE.  
DE...NONE.  
MD...NONE.  
MARINE...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR ANZ450-  
451.  
 

 
 

 
 
DISCUSSION...FITZSIMMONS  
AVIATION...FITZSIMMONS/GORSE/OHARA/RCM  
MARINE...FITZSIMMONS/GORSE/MJL/OHARA  
 
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