121  
FXUS61 KPHI 280121  
AFDPHI  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ  
921 PM EDT THU MAR 27 2025  
   
SYNOPSIS  
 
HIGH PRESSURE WILL SHIFT OFFSHORE AND REMAIN IN THE VICINITY OF  
BERMUDA THROUGH THE WEEKEND. A WEAK WARM FRONT WILL LIFT NORTH  
ACROSS THE REGION TONIGHT BEFORE A MORE POTENT WARM FRONT PUSHES  
ACROSS THE AREA FRIDAY NIGHT, RESULTING IN A MUCH WARMER  
SATURDAY. THE FRONT WILL SAG BACK SOUTH ON SATURDAY NIGHT  
BEFORE LIFTING BACK NORTH OF THE AREA ON SUNDAY. A LOW PRESSURE  
SYSTEM WILL APPROACH THE REGION ON MONDAY WITH A COLD FRONTAL  
PASSAGE ON MONDAY NIGHT. HIGH PRESSURE WILL THEN RETURN FOR  
TUESDAY AND WEDNESDAY.  
 
 
   
NEAR TERM /THROUGH FRIDAY/  
 
FORECAST IS ON TRACK THIS EVENING. ONLY SOME MINOR TWEAKS MADE  
BUT NOTHING OF SIGNIFICANCE.  
 
INITIAL RELATIVELY WEAK WARM FRONT WILL CROSS THE REGION  
TONIGHT, RESULTING IN SOME INCREASE IN CLOUDS FOR A TIME  
ESPECIALLY ACROSS NORTHERN REGIONS, ALONG WITH WINDS BECOMING  
MORE SOUTHERLY. LOWS WILL GENERALLY BE MILDER THAN LAST NIGHT,  
BUT STILL NEAR OR SLIGHTLY BELOW NORMAL, WITH LOW-MID 30S  
COMMON.  
 
ANY MORNING SUN TOMORROW SHOULD FADE BEHIND INCREASING CLOUDS AS  
A STRONGER WARM FRONT APPROACHES FROM THE WEST. GUIDANCE THIS  
AFTERNOON AND EVENING HAS SPED UP THE APPROACH OF SOME SHOWERS,  
BUT WITH SO MUCH DRY AIR IN THE LOW-LEVELS, THINKING IT WILL BE  
MORE OF THE LIGHT SPRINKLE VARIETY THROUGH THE AFTERNOON. POPS  
GRADUALLY INCREASE AS THE AFTERNOON GOES ON FROM WEST TO EAST  
BUT ONLY TOP OUT AROUND 20-30% DURING DAYLIGHT HOURS. THAT  
SAID, THE INITIAL PUSH OF MILDER AIR BEHIND TONIGHT'S WEAK FRONT  
SHOULD STILL HELP BRINGS TEMPS INTO THE 60S FOR MOST OF THE  
REGION DESPITE THE INCREASING CLOUDS.  
 
 
   
SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/  
 
THE SHORT TERM PERIOD WILL FEATURE AN EARLY-SUMMER LIKE WEATHER  
PATTERN AS A VERY WARM AIRMASS DEVELOPS OVER THE AREA.  
 
THE UPPER TROUGH THAT HAS BEEN OVER THE NORTHEAST US THE LAST COUPLE  
DAYS PULLS AWAY ON FRIDAY. FLOW ALOFT WILL BECOME ZONAL THROUGH  
SATURDAY AS AN UPPER TROUGH MOVES INTO THE CENTRAL US ALLOWING THE  
RIDGE TO AMPLIFY OVER THE EASTERN US ON SUNDAY. AT THE SURFACE, HIGH  
PRESSURE WILL BE LOCATED OVER THE WESTERN ATLANTIC IN THE VICINITY  
OF BERMUDA THROUGH THE WEEKEND. A WARM FRONT WILL LIFT NORTH OF THE  
AREA ON FRIDAY NIGHT ALLOWING THE ENTIRE AREA TO BE IN THE WARM  
SECTOR ON SATURDAY. THE FRONT WILL SAG BACK SOUTH ON SATURDAY NIGHT  
ACROSS PORTIONS OF THE AREA, BUT THIS APPEARS TO BE SHORT-LIVED AS  
THE FRONT LIFTS CLEAR OF THE AREA AGAIN ON SUNDAY.  
 
SO WHAT DOES THIS MEAN? FOR FRIDAY NIGHT, SOME ENERGY ALOFT  
WILL BE ACCOMPANIED WITH THE PASSING WARM FRONT. AS FORCING FOR  
ASCENT INCREASES, SHOULD SEE A BAND OF SHOWERS DEVELOP, SO HAVE  
KEPT 20-40% POPS ACROSS THE AREA. QPF WILL BE MINIMAL HOWEVER,  
PERHAPS A FEW HUNDREDTHS OF AN INCH AT MOST. LOWS WILL BE MILD  
RANGING FROM THE MID 40S TO MID 50S.  
 
FOR SATURDAY, THE REGION WILL BE LOCATED IN THE WARM SECTOR, SO  
EXPECTING A VERY MILD START TO THE WEEKEND. DESPITE SOME CLOUDS  
AROUND, STRONG SOUTH-SOUTHWESTERLY FLOW WILL ALLOW AFTERNOON HIGHS  
TO SOAR WELL INTO THE 70S, AND PERHAPS SURPASSING THE 80 DEGREE MARK  
IN SOME SPOTS WITH 60S IN THE POCONOS AND ALONG THE COAST. SHOULD  
FALL WELL SHORT OF ANY RECORDS, BUT THIS DOES LOOK TO BE OUR WARMEST  
DAY OF THE SEASON THUS FAR. LATEST GUIDANCE SUGGESTS THAT THE FRONT  
WILL SAG BACK SOUTH ON SATURDAY NIGHT ACROSS NORTHERN PORTIONS OF  
THE AREA. THIS WILL RESULT IN ANOTHER CHANCE FOR SHOWERS ESPECIALLY  
NORTH OF PHILLY WITH TEMPERATURES REMAINING MILD IN THE UPPER 40S TO  
UPPER 50S. THE FRONT SHOULD GRADUALLY MAKE ITS WAY BACK NORTH AGAIN  
ON SUNDAY. SO WHILE TEMPERATURES ARE NOT EXPECTED TO BE QUITE AS  
WARM COMPARED TO SATURDAY THANKS TO MORE CLOUD COVER AND SHOWERS  
AROUND, STILL EXPECTING HIGHS IN THE 60S AND 70S.  
 
 
   
LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/  
 
UPPER TROUGH WILL BEGIN TO APPROACH THE REGION ON SUNDAY NIGHT AS  
SURFACE LOW PRESSURE TRACKS ACROSS THE SOUTHERN GREAT LAKES AND INTO  
SOUTHERN QUEBEC ON MONDAY. A COLD FRONT WILL TRAIL BACK TO THE WEST  
AND CROSS THROUGH THE AREA LATE IN THE DAY ON MONDAY INTO MONDAY  
NIGHT. SHOWERS AND ISOLATED THUNDERSTORMS WILL BE ACCOMPANIED WITH  
THE FRONT AS IT TRACKS THROUGH, BUT IT IS QUITE TOO EARLY FOR ANY  
SPECIFICS. DEPENDING ON THE AMOUNT OF DESTABILIZATION THAT OCCURS  
AHEAD OF THE FRONT IN COMBINATION WITH MODEST FLOW ALOFT, THIS MAY  
SUPPORT A FEW STRONG TO SEVERE STORMS TO OCCUR WITH THE FRONT. THIS  
IS SUPPORTED BY THE CSU-MLP GUIDANCE AND BY THE STORM PREDICTION  
CENTER WHICH HAS PORTIONS OF THE REGION IN THE SEVERE WEATHER  
OUTLOOK ON MONDAY.  
 
BEHIND THE FRONTAL PASSAGE, WE'LL START TO SEE SOME IMPROVEMENT AS  
CANADIAN HIGH PRESSURE RETURNS FOR TUESDAY AND WEDNESDAY. ANOTHER  
DISTURBANCE WILL APPROACH FROM THE WEST LATE IN THE DAY ON  
WEDNESDAY, BUT CURRENT GUIDANCE SUGGESTS THAT ANY PRECIPITATION  
SHOULD HOLD OFF UNTIL AT LEAST WEDNESDAY NIGHT AND POTENTIALLY  
INTO THURSDAY.  
 
IN TERMS OF TEMPERATURES, ANOTHER WARM DAY IS EXPECTED ON MONDAY  
WITH TEMPERATURES ROUGHLY 15-20 DEGREES ABOVE NORMAL. ONCE THE FRONT  
PASSES THROUGH, WE'LL SEE TEMPERATURES RETURN TO MORE SEASONABLE  
LEVELS FOR TUESDAY AND WEDNESDAY BEFORE WARMING UP AGAIN WITH  
THE NEXT SYSTEM FOR THURSDAY.  
 
 
   
AVIATION /02Z FRIDAY THROUGH TUESDAY/  
 
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,  
KILG, KMIV, KACY AND SURROUNDING AREAS.  
 
TONIGHT...VFR. SW WINDS AROUND 5 KTS. MID AND HIGH CLOUDS  
FILTER IN AS THE NIGHT GOES ON. HIGH CONFIDENCE.  
 
FRIDAY...VFR. SOUTHWESTERLY WINDS AROUND 5-10 KT. CLOUD BASES  
LOWER THROUGH THE DAY WITH SOME SCATTERED LIGHT SHOWERS MOVING  
IN AFTER 18Z. ANY SHOWERS THAT MOVE DIRECTLY OVER A TERMINAL  
SHOULD NOT DROP CONDITIONS BELOW VFR THOUGH. MODERATE CONFIDENCE  
OVERALL.  
 
FRIDAY NIGHT...PRIMARILY VFR. SOME SCATTERED LIGHT SHOWERS  
AROUND WHICH COULD DROP CONDITIONS TO MVFR BRIEFLY, BUT  
EXPECTING A MAJORITY, IF NOT ALL OF THE PERIOD, TO STAY VFR.  
CIGS GENERALLY AROUND 4000 FEET OR HIGHER.  
 
OUTLOOK...  
 
SATURDAY THROUGH SATURDAY NIGHT...MAINLY VFR EXPECTED. SUB- VFR  
CONDITIONS POSSIBLE ON SATURDAY NIGHT IN ASSOCIATION WITH LIGHT  
RAIN SHOWERS. GUSTY WINDS UP TO 25 KT POSSIBLE ON SATURDAY.  
 
SUNDAY THROUGH MONDAY...MAINLY VFR EXPECTED ON SUNDAY. SUB-VFR  
CONDITIONS POSSIBLE THEREAFTER. RAIN SHOWERS BECOMING MORE LIKELY  
BY SUNDAY NIGHT WITH A CHANCE OF SHOWERS AND THUNDERSTORMS ON MONDAY.  
 
TUESDAY...VFR CONDITIONS WITH NO SIGNIFICANT WEATHER EXPECTED.  
 
 
   
MARINE  
 
HIGH PRESSURE WILL BE IN CONTROL. SUB-SMALL CRAFT ADVISORY  
CONDITIONS ON TAP THROUGH FRIDAY. SOUTHWESTERLY WINDS AROUND  
10-20 KT. SEAS 2 TO 3 FEET.  
 
OUTLOOK...  
 
FRIDAY NIGHT THROUGH SATURDAY...SCA CONDITIONS POSSIBLE ON THE  
ATLANTIC COASTAL WATERS DUE TO SEAS AROUND 4-6 FEET.  
 
SATURDAY NIGHT THROUGH SUNDAY...LINGERING SCA CONDITIONS POSSIBLE  
EARLY, BUT OVERALL NO MARINE HEADLINES EXPECTED.  
 
SUNDAY NIGHT THROUGH TUESDAY...SCA CONDITIONS PROBABLE ON THE  
ATLANTIC COASTAL WATERS DUE TO WIND GUSTS NEAR 25 KT AND SEAS  
AROUND 4-6 FEET.  
 
 
   
PHI WATCHES/WARNINGS/ADVISORIES  
 
PA...NONE.  
NJ...NONE.  
DE...NONE.  
MD...NONE.  
MARINE...NONE.  
 
 
 
 
 
SYNOPSIS...DESILVA/RCM  
NEAR TERM...HOEFLICH/RCM  
SHORT TERM...AKL/DESILVA  
LONG TERM...AKL/DESILVA  
AVIATION...AKL/GUZZO/HOEFLICH  
MARINE...AKL/RCM  
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