026  
FXUS61 KPHI 260641  
AFDPHI  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ  
141 AM EST MON FEB 26 2024  
   
SYNOPSIS
 
 
HIGH PRESSURE BUILDS IN FROM THE WEST AND MOVES OFFSHORE BY  
TOMORROW. A WARM FRONT MOVES THROUGH ON MONDAY NIGHT INTO TUESDAY.  
SEVERAL WAVES OF LOW PRESSURE WILL THEN PASS THROUGH THE REGION  
UNTIL A COLD FRONT MOVES THROUGH THE REGION ON THURSDAY. HIGH  
PRESSURE RETURNS FOR THE END OF THE WORK WEEK. A SYSTEM MAY SLIDE BY  
TO THE SOUTH THIS WEEKEND, PARTIALLY CLIPPING THE REGION.  
 

 
   
NEAR TERM /THROUGH TODAY/
 
 
CLOUDS HAVE INCREASE ACROSS THE AREA AHEAD OF AN APPROACHING  
SHORT WAVE/VORTICITY IMPULSE AS AN AREA OF ENHANCED MOISTURE  
MOVES INTO THE AREA AS WELL. THE COMBINATION OF THE SHORT WAVE  
AND INCREASE MOISTURE COULD LEAD TO SOME LIGHT PRECIPITATION  
LATER TONIGHT AND INTO THE MORNING HOURS JUST AFTER DAYBREAK.  
THERE REMAINS PRETTY DRY AIR AT THE SURFACE, SO IT MAY TAKE A  
WHILE FOR THE PRECIPITATION TO MAKE IT TO THE SURFACE. MOST  
PRECIPITATION WILL LIKELY BE FLURRIES OR SPRINKLES AND NOT LEAD  
TO MUCH IN THE WAY OF MEASURABLE PRECIPITATION. THE MOST LIKELY  
AREAS FOR A HUNDREDTH OR TWO WOULD BE AROUND THE I-80 CORRIDOR  
NORTHWARD.  
 
AFTER AFOREMENTIONED WEAK SYSTEM PASSES, WARM ADVECTION TAKES  
FULL EFFECT LATER ON MONDAY, WITH SUNSHINE RETURNING AND A BIG  
SURGE OF MILDER AIR. TEMPS SHOULD QUICKLY RISE INTO THE 50S ON  
SOUTHWESTERLY WINDS, WITH NEAR 60 FROM PHILLY ON SOUTH.  
 

 
   
SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/
 
 
AS LOW PRESSURE MOVES THROUGH THE NORTHERN AND CENTRAL PLAINS AND  
INTO THE UPPER GREAT LAKES, A WARM FRONT WILL APPROACH MONDAY NIGHT  
AND WILL LIFT NORTH THROUGH THE MID-ATLANTIC AND NORTHEAST ON  
TUESDAY. WARM AIR ADVECTION WILL BE UNDERWAY WITH STRONG SOUTHERLY  
FLOW DEVELOPING OVER THE AREA DUE TO A TIGHT PRESSURE GRADIENT  
BETWEEN THE APPROACHING LOW AND HIGH PRESSURE OFFSHORE. THIS  
COULD RESULT IN SOME MARINE FOG OR LOW STRATUS DEVELOPING AND  
MOVING INTO SE NJ. HAVE INCLUDED A MENTION OF PATCHY FOG FOR  
AREAS MOST AT RISK FOR THIS ON MONDAY NIGHT. RAIN DEVELOPS LATE  
TUESDAY AND CONTINUES THROUGH TUESDAY NIGHT AS SEVERAL MID  
LEVEL SHORTWAVES AS WELL AS ANOTHER WARM FRONT LIFTS THROUGH THE  
REGION. SHOULD JUST BE SOME PERIODS OF RAIN AS MODELS KEEP ANY  
INSTABILITY OFF TO THE WEST.  
 
HIGHS ON TUESDAY WARM WELL INTO THE LOW TO MID 60S, AND LOWS TUESDAY  
NIGHT WILL BE IN THE 50S. NORMAL HIGHS FOR LATE FEBRUARY ARE  
GENERALLY IN THE MID TO UPPER 40S AND NORMAL LOWS ARE IN THE 20S.  
 
THE COLD FRONT APPROACHES FORM THE WEST ON WEDNESDAY. STRONG  
SOUTHERLY FLOW WILL BE IN PLACE WEDNESDAY AND WEDNESDAY NIGHT, WITH  
WINDS GENERALLY RANGING FROM 15 TO 25 MPH WITH 35 TO 45 MPH GUSTS. A  
WIND ADVISORY MAY BE NEEDED FOR ALONG THE NEW JERSEY COAST DURING  
THIS TIME.  
 
WEDNESDAY WILL BE FAIRLY WARM AND HUMID (FOR THIS TIME OF YEAR) WITH  
HIGHS IN THE 60S AND DEW POINTS IN THE 50S. IT LOOKS LIKE RECORDS  
WILL BE SAFE FOR NOW HOWEVER. PWATS WILL BE UP AROUND 1.25 INCHES. A  
DEEP UPPER TROUGH AND STRONG SHORTWAVE ENERGY APPROACHES FROM THE  
WEST WEDNESDAY NIGHT, PUSHING THE FRONT THROUGH THE REGION LATE  
WEDNESDAY NIGHT/EARLY THURSDAY MORNING. THE 12Z/25 GFS IS NOW MUCH  
MORE IN LINE WITH WHAT THE ECMWF HAS BEEN SHOWING FOR A FEW DAYS  
NOW, WHICH IS A FASTER FRONTAL PASSAGE AND A MAINLY DRY THURSDAY.  
THE 12Z GEM LAGS BEHIND BY ABOUT 12 HOURS OR SO. THINKING THE  
FASTER SOLUTION IS STILL THE FINAL OUTCOME HERE THOUGH PERHAPS  
NOT AS FAST AS THE 12Z GFS/ECMWF HAVE IT. EITHER WAY, THE FRONT  
SHOULD BE WELL OUT OF THE REGION BY THURSDAY AFTERNOON, WITH  
STRONG COLD AIR ADVECTION SETTING UP WITH WEST/NORTHWESTERLY  
FLOW. AS THE FRONT APPROACHES WEDNESDAY EVENING, SHOWERS WITH  
LOCALLY MODERATE TO HEAVY RAIN WILL MOVE THROUGH. GUIDANCE HAS  
BEEN HIT OR MISS WITH ANY INSTABILITY, AND KEEPS WHAT LITTLE  
MUCAPE THERE IS MORE TO THE WEST. HOWEVER, THERE COULD BE A  
RUMBLE OF THUNDER WITH THE HEAVIER LINE COMING IN, MAINLY FOR  
AREAS WEST OF PHILADELPHIA.  
 

 
   
LONG TERM /THURSDAY THROUGH SUNDAY/
 
 
THE LAST OF THE SHOWERS SHOULD PUSH OUT BY THURSDAY MORNING WITH  
HIGH PRESSURE BUILDING IN FROM THE WEST BY THURSDAY AFTERNOON.  
IT WILL BE A BIT BLUSTERY IN THE WAKE OF THE DEPARTING FRONT,  
WITH NORTHWEST WINDS IN THE WAKE OF THE FRONT GUSTING TO 30-40  
MPH. WINDS DIMINISH IN THE EVENING AS THE GRADIENT WEAKENS AND  
HIGH PRESSURE SLIDES OVERHEAD. HIGHS ON THURSDAY WILL BE AROUND  
20 DEGREES COOLER COMPARED TO WEDNESDAY, GENERALLY TOPPING OFF  
IN THE MID AND UPPER 40S. LOWS ON THURSDAY NIGHT WILL GET DOWN  
INTO THE 20S.  
 
THE SURFACE HIGH WILL QUICKLY MOVE OFFSHORE BY FRIDAY AND CONDITIONS  
SHOULD BE DRY ON FRIDAY WITH RETURN FLOW SETTING UP. THIS WILL  
RESULT IN TEMPERATURES WARMING UP BY A FEW DEGREES, GETTING BACK  
INTO THE MID TO UPPER 40S, THOUGH SOME SPOTS MAY GET INTO THE 50S.  
 
AN UPPER TROUGH APPROACHES FROM THE WEST FRIDAY NIGHT, AND WEAK LOW  
PRESSURE SHOULD DEVELOP, PASSING SOUTH OF THE REGION ON SATURDAY.  
FOR NOW, STUCK CLOSE TO THE NBM AS DETERMINISTIC GUIDANCE REMAINS  
ALL OVER THE PLACE. MAINTAINED SLIGHT CHANCE (15-20%) POPS FOR  
THE WEEKEND. WHAT WE HAVE MORE CONFIDENCE IN IS TEMPERATURES  
GETTING BACK ABOVE NORMAL FOR SATURDAY AND ESPECIALLY SUNDAY,  
WHERE 60S ARE CERTAINLY ON THE TABLE YET AGAIN.  
 

 
   
AVIATION /06Z MONDAY THROUGH FRIDAY/
 
 
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,  
KILG, KMIV, KACY AND SURROUNDING AREAS...  
 
REST OF TONIGHT...VFR. SMALL CHANCE OF A SPRINKLE/FLURRY FOR THE  
NORTHERN TERMINALS LATE IN THE NIGHT AND TOWARD DAYBREAK.  
SOUTHERLY WINDS 5-10 KNOTS OR LESS. MODERATE CONFIDENCE.  
 
MONDAY...VFR. WINDS BEGIN OUT OF THE SOUTH 5-10 KNOTS, THEN  
SHIFT TO THE SOUTHWEST AND WEST DURING THE DAY. HIGH  
CONFIDENCE.  
 
MONDAY NIGHT...VFR. WINDS SHIFT TO THE SOUTHEAST AROUND 5 KNOTS  
OR LESS DURING THE EVENING, THEN BECOME LIGHT AND VARIABLE MOST  
PLACES OVERNIGHT. MODERATE CONFIDENCE.  
 
OUTLOOK...  
 
TUESDAY...PRIMARILY VFR, THOUGH SOME SHOWERS POSSIBLE LATE IN THE  
DAYTIME PERIOD. SOUTHERLY WINDS AROUND 10-20 KT AND GUSTS UP TO 25  
KT. MODERATE CONFIDENCE.  
 
TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...SUB-VFR CONDITIONS LIKELY  
WITH PERIODS OF RAIN. SOUTH/SOUTHWEST WINDS 15-25 KT AND 25-35 KT.  
LOW CONFIDENCE IN TIMING OF RESTRICTIONS, MODERATE TO HIGH  
CONFIDENCE IN OCCURRENCE.  
 
THURSDAY...PRIMARILY VFR AS A COLD FRONT PASSES IN THE MORNING,  
QUICKLY BRINGING CONDITIONS BACK TO VFR LEVELS. WEST/NORTHWEST WINDS  
10-20 KT AND GUSTS 20-30 KT. MODERATE CONFIDENCE.  
 
THURSDAY NIGHT...VFR. WESTERLY WINDS AROUND 5-10 KT. MODERATE  
CONFIDENCE.  
 
FRIDAY...VFR. SOUTHERLY WINDS AROUND 10 KT. MODERATE CONFIDENCE.  
 

 
   
MARINE
 
 
WINDS ARE EXPECTED TO STAY BELOW 25 KT THROUGH TOMORROW,  
ALTHOUGH A BRIEF PERIOD OF WIND GUSTS ABOVE 20 KT IS EXPECTED  
LATE TONIGHT. A SMALL CRAFT ADVISORY MAY BE NEEDED LATE TONIGHT  
INTO EARLY MONDAY MORNING AS SEAS GET CLOSE TO 5 FEET. HOWEVER,  
CURRENT SEAS ARE BELOW MODEL GUIDANCE, SO IT IS LOOKING  
INCREASINGLY UNLIKELY.  
 
WINDS AND SEAS AGAIN DIMINISH DURING THE BALANCE OF MONDAY, WITH  
NO HEADLINES ANTICIPATED.  
 
OUTLOOK...  
 
MONDAY NIGHT...NO MARINE HEADLINES ANTICIPATED. SOUTH/SOUTHEAST  
WINDS 10-15 KT AND SEAS 2 TO 4 FEET.  
 
TUESDAY...SCA CONDITIONS LIKELY. SOUTHERLY WINDS AROUND 15-25 KT AND  
GUSTS UP TO 30 KT. SEAS 3 TO 5 FEET.  
 
TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...SCA CONDITIONS EXPECTED WITH  
GALES LIKELY. SOUTH/SOUTHWEST WINDS 20-30 KT WITH GUSTS UP TO 40 KT.  
SEAS 5 TO 9 FEET.  
 
THURSDAY...GALES POSSIBLE THROUGH SOME OF THE DAY. NORTHWESTERLY  
WINDS 20-30 KT, WITH GUSTS 30-35 KT DECREASING LATER IN THE DAY.  
SEAS 4 TO 7 FEET.  
 
THURSDAY NIGHT..SCA CONDITIONS POSSIBLE EARLY WITH NORTHWEST WINDS  
15-20 KT AND GUSTS NEARING 25 KT. SEAS WILL AROUND 2-4 FEET.  
 
FRIDAY...NO MARINE HEADLINES ANTICIPATED. EAST/SOUTHEAST WINDS  
AROUND 10-15 KT AND SEAS 2-3 FEET.  
 

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

 
 

 
 
SYNOPSIS...HOEFLICH/RCM  
NEAR TERM...JOHNSON/RCM/ROBERTSON  
SHORT TERM...HOEFLICH/JOHNSON/MPS  
LONG TERM...HOEFLICH/MPS  
AVIATION...HOEFLICH/JOHNSON/RCM/ROBERTSON  
MARINE...HOEFLICH/JOHNSON/RCM  
 
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