813  
FXUS61 KPHI 200752  
AFDPHI  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ  
352 AM EDT SAT OCT 20 2018  
   
SYNOPSIS
 
 
A COLD FRONT EXTENDED ACROSS THE EASTERN GREAT LAKES EARLY THIS  
MORNING. THE BOUNDARY WILL PROGRESS TO THE SOUTHEAST AND IT IS  
EXPECTED TO PASS THROUGH OUR REGION AROUND MIDDAY. A SECONDARY  
COLD FRONT IS ANTICIPATED TO FOLLOW TONIGHT. HIGH PRESSURE IS  
FORECAST TO BUILD ACROSS NORTHEASTERN MARYLAND, DELAWARE,  
EASTERN PENNSYLVANIA AND NEW JERSEY FROM THE WEST ON SUNDAY AND  
MONDAY. ANOTHER COLD FRONT IS EXPECTED ON TUESDAY, THEN HIGH  
PRESSURE SHOULD INFLUENCE OUR WEATHER FOR WEDNESDAY, THURSDAY  
AND FRIDAY.  
 

 
   
NEAR TERM /UNTIL 6 PM THIS EVENING/
 
 
AN AREA OF LIGHT RAIN SHOWERS WAS LOCATED IN OUR REGION EARLY  
THIS MORNING. THE PRECIPITATION WAS OUT AHEAD OF A COLD FRONT  
APPROACHING FROM THE EASTERN GREAT LAKES. THE BACK EDGE OF THE  
SHOWERS WAS ALREADY IN THE SUSQUEHANNA RIVER VALLEY AROUND 3:30  
AM. EXTRAPOLATION PUTS MOST OF THE SHOWERS OFF THE COAST BY 9:00  
AM.  
 
CLOUDS ARE EXPECTED TO LINGER THIS MORNING UNTIL THE COLD FRONT  
PASSES THROUGH OUR REGION AROUND MIDDAY. WE ARE ANTICIPATING  
SOME BREAKS IN THE CLOUD COVER THIS AFTERNOON IN THE WAKE OF THE  
FRONT.  
 
THE WIND IS FORECAST TO BE FROM THE SOUTHWEST AHEAD OF THE THE  
BOUNDARY, THEN IT IS EXPECTED TO SHIFT TO THE WEST FOR THIS  
AFTERNOON. SPEEDS SHOULD BE MAINLY AROUND 10 MPH.  
 
MAXIMUM TEMPERATURES ARE ANTICIPATED TO FAVOR THE 60S IN OUR  
REGION TODAY, WITH READINGS NOT GETTING ABOVE THE 50S IN THE  
ELEVATED TERRAIN OF THE POCONOS AND FAR NORTHERN NEW JERSEY.  
 

 
   
SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SUNDAY/
 
 
A ROBUST MID LEVEL SHORT WAVE TROUGH WAS DROPPING TOWARD THE  
WESTERN GREAT LAKES FROM THE NORTHWEST EARLY THIS MORNING. THE  
FEATURE WILL CONTINUE TO PROGRESS SOUTHEASTWARD TODAY. ITS AXIS  
IS EXPECTED TO PASS OVER OUR REGION AROUND DAYBREAK ON SUNDAY.  
 
A SECONDARY SURFACE COLD FRONT IS FORECAST TO PRECEDE THE MID  
LEVEL SHORT WAVE AND IT SHOULD MAKES ITS WAY ACROSS EASTERN  
PENNSYLVANIA, NEW JERSEY, NORTHEASTERN MARYLAND AND DELAWARE  
OVERNIGHT. WE ARE ANTICIPATING SOME CLOUDS IN THE LIFT AHEAD OF  
THE MID LEVEL FEATURE. ALSO, THERE MAY BE SOME ISOLATED TO  
SCATTERED LIGHT RAIN SHOWERS.  
 
A WEST WIND AROUND 5 TO 10 MPH IS EXPECTED TO BECOME NORTHWEST  
AT 10 TO 15 MPH ONCE THE SECONDARY COLD FRONT PASSES.  
TEMPERATURES WILL LIKELY FALL INTO THE 30S IN THE POCONOS AND  
FAR NORTHERN NEW JERSEY, AND INTO THE LOWER AND MIDDLE 40S IN  
THE REST OF OUR REGION.  
 

 
   
LONG TERM /SUNDAY THROUGH FRIDAY/
 
 
SUNDAY AND MONDAY...BEHIND THE SECONDARY FRONT, EXPECT A LARGE  
AREA OF HIGH PRESSURE TO BUILD ACROSS FROM THE PLAINS STATES AND  
INTO THE MID-ATLANTIC, KEEPING DRY FOR A COUPLE OF DAYS. A  
STRONG UPPER TROUGH WILL ROTATE THROUGH THE REGION AND REINFORCE  
THE ARRIVAL OF SOME COLDER AIR FOR SUNDAY AND MONDAY. THE  
AIRMASS SHOULD MODIFY SLIGHTLY ON MONDAY BUT TEMPERATURES WILL  
STILL REMAIN COLDER THAN NORMAL. TEMPERATURES WILL GENERALLY  
REMAIN IN THE 40S TO LOWER 50S (UPPER 30S ACROSS NE  
PENNSYLVANIA) ON SUNDAY.  
 
THE GRADIENT IS PRETTY TIGHT, ESPECIALLY ON SUNDAY, AND WE MAY  
SEE SOME GUSTS AROUND 30 TO 35 MPH THROUGH THE DAY IN THE STRONG  
NORTHWEST FLOW. THE SUN WILL BE SHINING BUT WITH TEMPS ONLY IN  
THE 40S TO 50S, THE WIND WILL MAKE IT FEEL AT LEAST 10 DEGREES  
COLDER THAN IT ACTUALLY IS OUTSIDE.  
 
THE GRADIENT SHOULD WEAKEN FOR MONDAY HELPING TO MAKE IT FEEL  
WARMER THAN SUNDAY, EVEN THOUGH IT MAY ONLY BE BY AROUND 5  
DEGREES OR SO.  
 
TUESDAY...THE NEXT COLD FRONT ARRIVES ON TUESDAY. MODELS SHOW  
WHAT LOOKS TO BE A CLIPPER-LIKE SYSTEM MOVING OUT OF CANADA AND  
ACROSS THE GREAT LAKES BEFORE REACHING OUR AREA ON TUESDAY. IT'S  
A PRETTY FAST MOVING SYSTEM AND THE FRONT SHOULD HAVE NO  
PROBLEM MAKING ITS WAY THROUGH THE AREA BY TUESDAY NIGHT.  
GUIDANCE DIFFERS AS TO HOW MUCH MOISTURE WILL BE WITH THE FRONT  
AS IT MOVES THROUGH. WE MAY SEE SOME PRECIPITATION BUT CURRENT  
THINKING IS PRECIPITATION WILL BE FAIRLY LIGHT AND SHORT LIVED.  
 
WEDNESDAY THROUGH FRIDAY...STRONG SURFACE HIGH PRESSURE WILL  
BUILD INTO OUR AREA ON WEDNESDAY AND PERSIST THROUGH THE END OF  
THE WEEK. WE SHOULD REMAIN NICE AND DRY THROUGH THE PERIOD. SOME  
COLDER AIR WILL DIP DOWN FROM THE NORTH AND WE WILL SEE ANOTHER  
PERIOD OF BELOW NORMAL TEMPERATURES, ESPECIALLY FOR THURSDAY.  
 

 
   
AVIATION /08Z SATURDAY THROUGH WEDNESDAY/
 
 
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,  
KILG, KMIV, KACY AND SURROUNDING AREAS.  
 
TODAY...SHOWERS ENDING BY 13Z. CEILINGS VARYING FROM VFR TO  
MVFR THROUGH ABOUT 16Z, THEN VFR FROM AROUND 16Z ONWARD.  
SOUTHWEST WIND 6 TO 12 KNOTS BECOMING WEST AROUND 15Z TO 17Z  
WITH THE ARRIVAL OF A COLD FRONT FROM THE NORTHWEST.  
 
TONIGHT...VFR CEILINGS. SCATTERED TO ISOLATED LIGHT RAIN  
SHOWERS. WEST WIND 6 TO 12 KNOTS BECOMING NORTHWEST 10 TO 15  
KNOTS AFTER 06Z.  
 
OUTLOOK...  
SUNDAY...VFR. NORTHWEST WIND NEAR 15 KNOTS GUSTING AROUND 25  
KNOTS.  
 
SUNDAY NIGHT...VFR. NORTHWEST TO WEST WIND 8 KNOTS OR LESS.  
 
MONDAY...VFR. SOUTHWEST WIND 5 TO 10 KNOTS.  
 
MONDAY NIGHT...VFR. SOUTHWEST WIND 8 KNOTS OR LESS.  
 
TUESDAY...VFR. SOUTHWEST TO WEST WIND AROUND 10 KNOTS.  
 
TUESDAY NIGHT...VFR. NORTHWEST WIND 5 TO 10 KNOTS.  
 
WEDNESDAY...VFR. NORTHWEST WIND AROUND 10 KNOTS.  
 

 
   
MARINE
 
 
A COLD FRONT APPROACHING FROM THE NORTHWEST IS EXPECTED TO  
REACH THE COASTAL WATERS OF NEW JERSEY AND DELAWARE EARLY THIS  
AFTERNOON. SOUTHWESTERLY GALE FORCE GUSTS REMAIN POSSIBLE UNTIL  
ABOUT 6:00 AM ON OUR OCEAN WATERS. AS A RESULT, A GALE WARNING  
IS IN EFFECT UNTIL THAT TIME. THERE IS A SMALL CRAFT ADVISORY  
FOR DELAWARE BAY UNTIL NOON.  
 
WIND GUSTS IN EXCESS OF 25 KNOTS REMAIN POSSIBLE ON THE COASTAL  
WATERS OF NEW JERSEY INTO TONIGHT. HOWEVER, THERE MAY BE A LULL  
IN SMALL CRAFT ADVISORY CONDITIONS ON THE COASTAL WATERS OF  
DELAWARE AND ON DELAWARE BAY FROM THIS AFTERNOON INTO THIS  
EVENING.  
 
A SECONDARY COLD FRONT ARRIVING LATE TONIGHT IS ANTICIPATED TO  
BRING ANOTHER ROUND OF GALE FORCE GUSTS BEGINNING NEAR DAYBREAK  
ON SUNDAY.  
 
OUTLOOK...  
SUNDAY...GALE FORCE WIND GUSTS FROM THE NORTHWEST ARE LIKELY ON  
OUR OCEAN WATERS AND ON DELAWARE BAY.  
 
SUNDAY NIGHT...SMALL CRAFT ADVISORY CONDITIONS ARE EXPECTED  
DURING THE EVENING WITH WIND SPEEDS DECREASING OVERNIGHT.  
 
MONDAY AND MONDAY NIGHT...NO MARINE HEADLINES ARE ANTICIPATED.  
 
TUESDAY...A WEST WIND IS EXPECTED TO GUST IN EXCESS OF 25  
KNOTS.  
 
TUESDAY NIGHT AND WEDNESDAY...A NORTHWEST WIND IS EXPECTED TO  
GUST IN EXCESS OF 25 KNOTS.  
 

 
   
PHI WATCHES/WARNINGS/ADVISORIES
 
 
PA...NONE.  
NJ...NONE.  
DE...NONE.  
MD...NONE.  
MARINE...GALE WARNING UNTIL 6 AM EDT EARLY THIS MORNING FOR ANZ450>455.  
GALE WATCH FROM LATE TONIGHT THROUGH SUNDAY AFTERNOON FOR  
ANZ431-453>455.  
SMALL CRAFT ADVISORY UNTIL NOON EDT TODAY FOR ANZ430-431.  
 

 
 

 
 
SYNOPSIS...IOVINO  
NEAR TERM...IOVINO  
SHORT TERM...IOVINO  
LONG TERM...MEOLA  
AVIATION...IOVINO  
MARINE...IOVINO  
 
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