066  
FXUS61 KPHI 181943 CCA  
AFDPHI  
 
AREA FORECAST DISCUSSION...CORRECTED  
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ  
343 PM EDT THU SEP 18 2025  
   
SYNOPSIS
 
 
A WEAK AREA OF HIGH PRESSURE WILL REMAIN ACROSS THE MIDDLE  
ATLANTIC REGION TONIGHT AND INTO FRIDAY. A COLD FRONT WILL PUSH  
THROUGH THE REGION FRIDAY NIGHT. STRONG HIGH PRESSURE WILL BUILD  
SOUTHEAST INTO THE REGION THROUGH THE WEEKEND. THE HIGH  
PRESSURE WILL WEAKEN AND SHIFT SLOWLY EASTWARD THROUGH THE FIRST  
HALF OF NEXT WEEK, WITH MODERATING TEMPERATURES AND A FEW  
CHANCES FOR RAIN.  
 

 
   
NEAR TERM /THROUGH FRIDAY/
 
 
SURFACE HIGH PRESSURE AND RIDGING ALOFT HAVE BROUGHT SUNNY SKIES  
AND PLEASANT TEMPERATURES TO THE NORTHERN MIDDLE ATLANTIC REGION  
THIS AFTERNOON. TEMPERATURES INLAND HAVE CLIMBED INTO THE LOW/MID  
80S WHILE 70S CONTINUE FOR DELMARVA AND SE NJ WHERE CLOUDS PERSISTED  
LONGER EARLIER TODAY. WINDS HAVE BEEN RATHER LIGHT FROM THE N & NW.  
 
FOR TONIGHT, SKIES WILL REMAIN CLEAR WITH THE FAIR PATTERN CONTINUING.  
WE'LL PROBABLY HAVE AREAS OF FOG ACROSS SOUTHERN NJ AND DELMARVA  
IN AREAS THAT HAD MORE CLOUDS TODAY AND PLENTIFUL RAINS  
YESTERDAY. FOG WILL BE MORE PATCHY IN OTHER AREAS. THE DRIER AIR  
WILL CONTINUE TO ARRIVE FROM THE N/NW AND IT MAY NOT FULLY MAKE  
IT INTO THE S/E AREAS BEFORE SUNSET. LOWS WILL BE IN THE UPPER  
50S TO LOW 60S MOST SPOTS. WINDS WILL BE LIGHT.  
 
ANOTHER GOOD WEATHER DAY IS EXPECTED FRIDAY. PLENTY OF SUNSHINE  
EARLY THE SOME CLOUDS FOR THE AFTERNOON. IT WILL BE VERY WARM  
FOR THE END OF SEPTEMBER WITH HIGHS IN THE LOW/MID 80S ACROSS  
THE REGION. AREAS NEAR THE SHORE AND THE SOUTHERN POCONOS WILL  
HAVE HIGHS IN THE UPPER 70S. WINDS WILL BE LIGHT FAVORING THE  
SOUTH OR SOUTHWEST.  
 

 
   
SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/
 
 
THE COLD FRONT THAT WILL ENTIRE OUR AREA ON FRIDAY WILL FINISH  
PUSHING SOUTH AND CLEAR THE REGION BY SATURDAY MORNING. NO  
PRECIPITATION IS EXPECTED WITH THIS FRONTAL PASSAGE, BUT IT WILL  
BRING COOLER TEMPERATURES. LOWS ON FRIDAY NIGHT ARE EXPECTED TO BE  
IN THE UPPER 40S ACROSS THE HIGHER ELEVATIONS OF EASTERN PA AND FAR  
NORTHERN NJ, THE MID-UPPER 50S ACROSS SOUTHEASTERN PA OUTSIDE OF THE  
URBAN CORRIDOR AND NJ AWAY FROM THE COAST, AND NEAR 60 FOR COASTAL  
LOCATIONS, THE URBAN CORRIDOR, AND THE DELMARVA.  
 
WITH HIGH PRESSURE IN CONTROL ON SATURDAY, PARTLY CLOUDY SKIES AND  
HIGHS IN THE MID 70S ARE EXPECTED. AS THE HIGH SLIDES SLOWLY  
SOUTHEASTWARD SATURDAY NIGHT AND SUNDAY, THE AREA WILL BE POSITIONED  
BETWEEN THE HIGH CENTER TO THE NORTHEAST AND A STATIONARY BOUNDARY  
ACROSS PORTIONS OF THE MID-ATLANTIC. THIS WILL SET THE STAGE FOR A  
PERIOD OF ONSHORE FLOW AND SOME INCREASE IN CLOUD COVER FOR SATURDAY  
NIGHT AND SUNDAY. A SPRINKLE OR TWO CANNOT BE RULED OUT ACROSS THE  
DELMARVA OR NEAR THE SOUTHEASTERN COAST OF NJ, HOWEVER, THIS DOESN'T  
APPEAR TO WARRANT TO INCLUSION OF POPS AT THIS TIME GIVEN THE  
AIRMASS IN PLACE WILL BE FAIRLY DRY.  
 
LOW TEMPERATURES SATURDAY NIGHT WILL LIKELY AGAIN BE IN THE UPPER  
40S ACROSS THE HIGHER ELEVATIONS OF EASTERN PA AND FAR NORTHERN NJ,  
AND IN THE MID 50S TO LOWER 60S ELSEWHERE. HIGHS ON SUNDAY ARE  
EXPECTED TO BE IN THE LOW-MID 70S AREAWIDE. LOWS SUNDAY NIGHT WILL  
RANGE FROM THE LOW 50S ACROSS NORTHERN PARTS OF THE AREA TO THE  
UPPER 50S ALONG THE COAST, IN THE URBAN CORRIDOR, AND THE DELMARVA.  
 

 
   
LONG TERM /MONDAY THROUGH THURSDAY/
 
 
WEAK UPPER-RIDGING WILL BE IN PLACE ACROSS THE AREA MONDAY INTO  
MONDAY NIGHT, WITH SURFACE HIGH PRESSURE MAINTAINING STRONG  
INFLUENCE. MOISTURE WILL BE ON THE INCREASE HOWEVER AS SOUTHERLY  
FLOW RETURNS TO THE AREA. OVERALL, IT LOOKS TO BE A NICE DAY WITH  
PARTLY SUNNY SKIES AND TEMPERATURES RISING INTO THE MID-UPPER 70S  
AREAWIDE. TEMPERATURES OVERNIGHT SHOULD ALSO BE WARMER, WITH UPPER  
50S TO LOWER 60S BEING COMMON.  
 
BEGINNING ON TUESDAY, THE UPPER-PATTERN WILL BECOME SLIGHTLY MORE  
UNSETTLED. A SHORTWAVE AXIS SHOULD PASS TO THE NORTH OF THE FORECAST  
AREA TUESDAY INTO TUESDAY NIGHT. WHILE THE BEST FORCING SHOULD BE  
DISPLACED TO THE NORTH, THIS SYSTEM COULD BE ENOUGH TO TRIGGER  
ISOLATED SHOWERS AND PERHAPS A STORM OR TWO. THE HIGHEST CHANCE  
APPEARS TO BE TUESDAY AFTERNOON AND INTO THE OVERNIGHT HOURS. AFTER  
THE PASSAGE OF THIS SHORTWAVE, THE PATTERN LOOKS FAIRLY  
UNREMARKABLE, HOWEVER STILL UNSETTLED WITH PERHAPS A WEAK IMPULSE OR  
TWO PASSING THROUGH WEDNESDAY INTO THURSDAY. THEREFORE, SLIGHT  
CHANCE TO LOW-END CHANCE POPS APPEAR WARRANTED (20-30%) BOTH DAYS. A  
MORE NOTABLE UPPER-TROUGH AND ACCOMPANYING SURFACE LOW MAY BEGIN TO  
APPROACH THE AREA FROM THE WEST LATE THURSDAY AND ESPECIALLY BEYOND.  
 
TUESDAY AND WEDNESDAY LOOK FAIRLY SIMILAR IN TERMS OF TEMPERATURES,  
WITH HIGHS IN THE LOW 80S AND LOWS IN THE LOW 60S. THURSDAY  
CURRENTLY APPEARS TO BE SLIGHTLY COOLER WITH INCREASING MOISTURE AND  
CLOUD COVER, WITH HIGHS GENERALLY IN THE MID-UPPER 70S.  
 

 
   
AVIATION /18Z THURSDAY THROUGH TUESDAY/
 
 
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,  
KILG, KMIV, KACY AND SURROUNDING AREAS.  
 
THRU SUNSET... DECREASING CLOUDS FOR SE NJ AND DELMARVA. VFR  
EXPECTED. LIGHT NW TO W WINDS.  
 
TONIGHT... VFR CONDITIONS WITH MAINLY CLEAR SKIES EXPECTED.  
WE'LL LIKELY HAVE SOME RURAL FOG ACROSS DELMARVA AND SOUTH NJ  
LATE TONIGHT SO WE'LL INCLUDE THAT IN KMIV/KACY TAF SITES. OTHER  
SITES LESS CERTAIN WITH DRIER AIR ARRIVING THRU THE AFTERNOON.  
OVERALL HIGH CONFID, BUT ONLY MODERATE CONFID IN FOG OCCURRENCE/PLACEMENT.  
 
FRIDAY... VFR EXPECTED AFTER ANY EARLY FOG. DAYTIME CU/SC WITH SCT  
TO BKN 035-045 BASES. NORTHWEST WINDS AROUND 10 KNOTS BY AFTERNOON.  
MEDIUM/HIGH CONFID.  
 
OUTLOOK...  
 
FRIDAY NIGHT THROUGH SATURDAY...VFR. NO SIGNIFICANT WEATHER.  
 
SATURDAY NIGHT THROUGH SUNDAY NIGHT...RESTRICTIONS ARE POSSIBLE  
DEPENDING ON THE EXTENT OF POTENTIAL MARINE STRATUS.  
 
MONDAY THOUGH MONDAY NIGHT...VFR. NO SIGNIFICANT WEATHER.  
 
TUESDAY...PERIOD OF SUB-VFR CONDITIONS ARE POSSIBLE IN ISOLATED  
SHOWERS AND STORMS, PARTICULARLY DURING THE AFTERNOON HOURS.  
 

 
   
MARINE
 
 
FAIR WEATHER WILL CONTINUE ON THE WATERS TONIGHT AND FRIDAY. WEAK  
HIGH PRESSURE THE REST OF TODAY AND TONIGHT WILL KEEP WINDS RATHER  
LIGHT FAVORING A NW DIRECTION. A COLD FRONT WILL APPROACH FRIDAY AND  
WHILE NO SIGNIFICANT WEATHER IS EXPECTED WITH IT, WINDS WILL SWITCH  
BACK AROUND TO SOUTH AS IT APPROACHES. SEAS WILL BE MOSTLY AROUND 3  
FT INTO TONIGHT THEN CLOSER TO 2 FT FRIDAY. 1 TO 2 FT WAVES FOR  
DELAWARE BAY.  
 
OUTLOOK...  
 
FRIDAY NIGHT THROUGH MONDAY...NORTHERLY WINDS COULD APPROACH OR  
EXCEED 25 KT FRIDAY NIGHT INTO SATURDAY BEHIND THE COLD FRONT. IN  
ADDITION, SEAS WILL LIKELY BECOME ELEVATED, AT TIMES NEAR OR  
EXCEEDING 5 FEET, SUNDAY THROUGH MONDAY. THEREFORE, AN SCA WILL  
LIKELY BE NEEDED FOR AT LEAST PART OF THIS PERIOD.  
 
MONDAY NIGHT THROUGH TUESDAY...CONDITIONS ARE EXPECTED TO BE BELOW  
SCA CRITERIA WITH WINDS UNDER 25 KT AND SEAS UNDER 5 FEET.  
 
RIP CURRENTS...  
 
REST OF TODAY, LIGHT NORTHERLY WINDS EXPECTED. BREAKING WAVES OF  
2-3 FEET ALONG WITH AN EASTERLY SWELL AROUND 8 SECONDS ARE FORECAST.  
SINCE THE SWELL COMPONENT IS MORE PERPENDICULAR TO THE COAST DESPITE  
LOWERING WAVE HEIGHTS AND DECREASING WIND, MAINTAINED A MODERATE  
RISK FOR THE DEVELOPMENT OF DANGEROUS RIP CURRENTS FOR ALL BEACHES.  
 
FOR FRIDAY, A MORE SOUTHERLY WIND AROUND 5 TO 10 MPH IS  
FORECAST TO DEVELOP WITH AN EAST-SOUTHEAST SWELL AROUND 8  
SECONDS. BREAKING WAVES IN THE SURF ZONE ARE FORECAST TO BE A  
LITTLE LOWER, AND THEREFORE WENT WITH A LOW RISK FOR THE  
DEVELOPMENT OF DANGEROUS RIP CURRENTS AT ALL BEACHES.  
 
FOR SPECIFIC BEACH FORECASTS, VISIT WEATHER.GOV/BEACH/PHI  
 

 
 
   
PHI WATCHES/WARNINGS/ADVISORIES
 
 
PA...NONE.  
NJ...NONE.  
DE...NONE.  
MD...NONE.  
MARINE...NONE.  
 

 
 

 
 
SYNOPSIS...COOPER  
NEAR TERM...OHARA  
SHORT TERM...COOPER  
LONG TERM...COOPER  
AVIATION...COOPER/OHARA  
MARINE...COOPER/OHARA  
 
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