333  
FXUS61 KCTP 241211  
AFDCTP  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE STATE COLLEGE PA  
811 AM EDT MON JUL 24 2017  
   
SYNOPSIS
 
 
AN UPPER TROUGH, LOCATED OVER THE GREAT LAKES EARLY THIS  
MORNING, WILL PUSH SLOWLY ACROSS PENNSYLVANIA EARLY THIS WEEK.  
IN ITS WAKE, HIGH PRESSURE WILL BUILD SOUTHEAST ACROSS THE  
REGION BY MIDWEEK. A COLD FRONT WILL LIKELY PUSH SOUTHEAST  
ACROSS THE REGION NEXT FRIDAY.  
 

 
   
NEAR TERM /UNTIL 6 PM THIS EVENING/
 
 
FF WATCH AND ALL ADVISORIES HAVE NOW EXPIRED. BACK EDGE OF  
STEADY RAIN HAS EXITED TO THE EAST WITH ONLY ISOLATED A FEW  
ISOLATED SHRA LEFT AS WEAK SURFACE LOW OVER THE DELMARVA  
PENINSULA AND ASSOCIATED SOUTHEASTERLY LOW LEVEL JET LIFT OUT.  
 
UPPER TROUGH OVER THE GRT LKS IS POISED TO SWING INTO THE  
REGION LATER TODAY, CAUSING SCATTERED CONVECTION TO BREAK OUT  
ALONG AND AHEAD OF ASSOCIATED COLD FRONT AS EARLY AS MID  
MORNING OVER THE NORTHWEST MOUNTAINS, AND MAINLY DURING THE  
AFTERNOON ELSEWHERE.  
 
AFTER A CLOUDY START TO THE DAY IN MANY LOCATIONS, MODEL  
SOUNDINGS INDICATE A FAIR AMOUNT OF SUNSHINE DEVELOPING BY  
MIDDAY, AS LOWER PWAT AIR FILTERS IN ON WESTERLY FLOW. NCAR  
ENSEMBLE INDICATING PREFRONTAL CAPES RISING TO AROUND 1000 J/KG  
BY AFTERNOON ACROSS THE EASTERN 2/3RDS OF THE FORECAST AREA.  
THE COMBINATION OF MODEST CAPES AND 0-6KM SHEAR OF 40-45KTS WILL  
SUPPORT A MARGINAL THREAT OF SEVERE WEATHER DURING THE  
AFTERNOON. CONVECTION-ALLOWING MODELS INDICATE THE BEST CHANCE  
OF SHOWERS WILL COME DURING LATE MORNING/EARLY AFTERNOON ACROSS  
THE NORTHWEST MOUNTAINS, WITH MORE ROBUST CONVECTION FORMING  
ALONG COLD FRONT, AS IT PUSHES THROUGH THE REST OF THE FORECAST  
AREA DURING THE AFTERNOON HOURS.  
 

 
   
SHORT TERM /6 PM THIS EVENING THROUGH 6 AM TUESDAY/
 
 
UPPER TROUGH OVER THE GRT LKS IS POISED TO SWING INTO THE  
REGION LATER TODAY, CAUSING SCATTERED CONVECTION TO BREAK OUT  
ALONG AND AHEAD OF ASSOCIATED COLD FRONT AS EARLY AS MID  
MORNING OVER THE NORTHWEST MOUNTAINS, AND MAINLY DURING THE  
AFTERNOON ELSEWHERE.  
 
AFTER A CLOUDY START TO THE DAY IN MANY LOCATIONS, MODEL  
SOUNDINGS INDICATE A FAIR AMOUNT OF SUNSHINE DEVELOPING BY  
MIDDAY, AS LOWER PWAT AIR FILTERS IN ON WESTERLY FLOW. NCAR  
ENSEMBLE INDICATING PREFRONTAL CAPES RISING TO AROUND 1000 J/KG  
BY AFTERNOON ACROSS THE EASTERN 2/3RDS OF THE FORECAST AREA.  
THE COMBINATION OF MODEST CAPES AND 0-6KM SHEAR OF 40-45KTS WILL  
SUPPORT A MARGINAL THREAT OF SEVERE WEATHER DURING THE  
AFTERNOON. CONVECTION-ALLOWING MODELS INDICATE THE BEST CHANCE  
OF SHOWERS WILL COME DURING LATE MORNING/EARLY AFTERNOON ACROSS  
THE NORTHWEST MOUNTAINS, WITH MORE ROBUST CONVECTION FORMING  
ALONG COLD FRONT, AS IT PUSHES THROUGH THE REST OF THE FORECAST  
AREA DURING THE AFTERNOON HOURS.  
 

 
   
LONG TERM /TUESDAY THROUGH SUNDAY/
 
 
NOT A LOT OF CHANGE FROM YESTERDAY. STILL GOING MAINLY  
WITH DRY CONDITIONS TUESDAY INTO WED. DID LOWER TEMPERATURES  
A DEGREE OR SO ON TUE, GIVEN CONCERN FOR SOME CLOUDS AND  
LACK OF REAL STRONG COOL PUSH. ALSO MODELS SHOW PAIR OF WEAK  
LOWS JUST INLAND FROM THE SOUTH SHORE OF THE LOWER GREAT  
LAKES, NOT SURE WHAT TO MAKE OF THIS. A STRANGE SUMMER LATELY.  
 
STILL EXPECTING SHOWERS AND STORMS ON THURSDAY INTO THE FIRST  
PART OF FRIDAY, WITH THE NEXT COLD FRONT.  
 
WENT WITH MAINLY DRY CONDITIONS AFTER EARLY FRIDAY.  
 

 
   
AVIATION /12Z MONDAY THROUGH FRIDAY/
 
 
MOST SHRA ACTIVITY HAS EXITED TO THE EAST AS OF 12Z. GENERALLY  
MVFR CONDS PREVAIL OVER THE CENTRAL MTNS AND IFR OVER THE  
WESTERN/NORTHERN MTNS - WHICH WILL PERSIST INTO THE MID MORNING  
HOURS BEFORE IMPROVEMENT (LASTING THE LONGEST IN THE NW MTNS).  
 
AN UPPER TROUGH WILL PUSH SLOWLY ACROSS PENNSYLVANIA TODAY AND  
TUE. THIS WILL KICK OFF ANOTHER ROUND OF SHOWERS AND  
SCATTERED THUNDERSTORMS THIS AFTERNOON WITH INTERMITTANT  
LOCALIZED IMPACTS.  
 
SHOWERS DIMINISH BY EVENING, BUT LINGER THE LONGEST IN THE  
NORTHERN MTNS. THIS IS ALSO THE BEST CHANCE FOR CEILING  
RESTRICTIONS TONIGHT. WITH PLENTY OF LOW LEVEL MOISTURE AROUND,  
EXPECT VALLEY FOG TO DEVELOP AREAWIDE AS WELL.  
   
OUTLOOK
 
 
TUE-WED...AM CIG RESTRICTIONS NORTH/WEST. VALLEY FOG AREAWISE.  
OTHERWISE NO SIG WX.  
 
THU-FRI...CHANCE OF AFTERNOON TSRA/SHRA.  
 

 
   
CTP WATCHES/WARNINGS/ADVISORIES
 
 
NONE.  
 

 
 

 
SYNOPSIS...FITZGERALD  
NEAR TERM...DEVOIR/FITZGERALD  
SHORT TERM...DEVOIR/FITZGERALD  
LONG TERM...MARTIN  
AVIATION...DEVOIR/RXR  
 
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