984  
FXUS61 KCTP 222103  
AFDCTP  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE STATE COLLEGE PA  
403 PM EST MON JAN 22 2018  
   
SYNOPSIS
 
 
A POTENT AREA OF LOW PRESSURE MOVING ACROSS THE GREAT LAKES WILL  
PUSH A TRAILING COLD FRONT THROUGH THE COMMONWEALTH ON TUESDAY.  
TEMPERATURES WILL STAY ABOVE NORMAL INTO EARLY TUESDAY, BEFORE  
FALLING BACK TO NEAR OR SLIGHTLY BELOW NORMAL WEDNESDAY AND  
THURSDAY. DRY WEATHER IS EXPECTED FOR THE SECOND HALF OF THE  
WEEK. THE TEMPERATURES WILL REBOUND TO ABOVE NORMALS BY THE  
WEEKEND.  
 

 
   
NEAR TERM /UNTIL MIDNIGHT TONIGHT/
 
 
WARM FRONT HAS PASSED THRU MOST OF THE AREA, AND ONLY A FEW  
SPRINKLES ARE POSSIBLE IN THE NEXT TWO HOURS OVER THE FAR N/E.  
THE TEMPS ARE SOARING OVER THE SOUTH WITH JST ALMOST 60F AT 2  
PM. BUT, WIND JUST STARTING TO GET INTO THE MID AND UPPER SUSQ R  
VALLEY LOCATIONS. THEY WILL WARM UP A LITTLE THIS EVENING, THEN  
STAY NEARLY STEADY (AS WILL THE REST OF THE AREA) THROUGH THE  
REST OF THE NIGHT. OTHERWISE, IT WILL BE RATHER QUIET THROUGH  
THE EVENING. THE BAND OF SHOWERS ON OVER CENTRAL OH WILL  
CONTINUE EASTWARD BUT ALSO BREAK APART A BIT AS IT IS STRETCHED  
THIN AND GETS TOO FAR AWAY FROM UPPER SUPPORT. ANY RAIN FROM THE  
BAND SHOULD HOLD OFF UNTIL AFTER 9 OR 10PM, AND ONLY THE FAR NW  
IS LIKELY TO GET RAIN BEFORE MIDNIGHT.  
 

 
   
SHORT TERM /MIDNIGHT THROUGH 6 PM TUESDAY/
 
 
AGAIN, THE TEMPS SHOULD REMAIN FAIRLY STEADY THROUGH THE NIGHT,  
COOLING OFF A LITTLE AS THE RAIN FALLS. POPS WILL STAY HIGH, BUT  
PRECIP DOES NOT LOOK TO BE A SOLID AREA, RATHER A FEW LINES OF  
SHOWERS. THERE WILL BE SOME INSTABILITY DEVELOP THROUGH THE  
NIGHT AS THE OCCLUDED ZONE MOVES OVERHEAD. WE WILL MENTION A  
SLIGHT CHC THUNDER MOVING ACROSS THE STATE FROM W-E OVERNIGHT  
FOLLOWING THE LOWERED LIS ON BOTH GFS AND NAM ALOFT THRU THE  
NIGHT. BUT, THE CHC OF T LINGERS INTO THE DAY IN THE SE/LOWER  
SUSQ, AND MAY ACTUALLY BE GREATER IN THE DAYTIME ON FRIDAY IF  
THERE CAN BE SOME HEATING AS THE CFRONT ZIPS THRU. TEMPS WILL  
GET LOWER QUICKLY IN THE AFTN OVER THE NW AND LAURELS, AND ANY  
REMAINING SHRA SHOULD START TO MIX WITH SN. UPSLOPE AND MAIN LOW  
CLOUD SHIELD UNDER THE UPPER TROUGH WILL SUPPLY SUPPORT FOR SCT  
SHSN TUES EVENING.  
 

 
   
LONG TERM /TUESDAY NIGHT THROUGH MONDAY/
 
 
COLD FRONT AND LOW PRESSURE SYSTEM WILL BE LIFTING INTO NEW  
ENGLAND BY TUE NIGHT, WITH SECONDARY FRONT BRINGING COLDER AIR  
BACK INTO PA - ALONG WITH SNOW SHOWERS IN WESTERN SECTIONS THAT  
WILL TAPER OFF BY WED NIGHT (AFTER ONLY AMOUNTING TO AN INCH OR  
TWO). BREEZY WINDS UP TO 30 MPH WILL ALSO IMPACT CENTRAL PA  
DURING THAT TIME AS TEMPERATURES FALL BACK TO SEASONAL LEVELS.  
 
THU AND FRI WILL BE COOLER AS HIGH PRESSURE MOVES ACROSS THE  
REGION. EASTERN AREAS ESPECIALLY WILL SEE CHILLY MORNINGS AS DRY  
AIR/LOW DEWPOINTS ASSOCIATED WITH THE HIGH WILL BE IN PLACE.  
 
PROGRESSIVE PATTERN WILL BRING MODERATING TEMPERATURES BACK FOR  
THE WEEKEND AHEAD OF ANOTHER LOW PRESSURE AREA. CHANCES FOR RAIN  
INCREASE HEADING INTO SUNDAY, FOLLOWED BY A RETURN OF COOLER  
WEAATHER AND SNOW SHOWERS BEHIND A COLD FRONT MONDAY.  
 

 
   
AVIATION /21Z MONDAY THROUGH SATURDAY/
 
 
MAIN PROBLEM FOR THE NEXT 6-8 HOURS IS THE INCREASE IN WIND  
SPEED ALOFT AS A STRONG LOW LEVEL JET NOSES IN AND INTENSIFIES  
OVER PA. SSW WIND AT 2-3KFT WILL PEAK AROUND 55KT LATE TONIGHT.  
A COLD FRONT WILL PUSH THROUGH AROUND SUNRISE IN THE W, AND  
EARLY AFTN IN THE E. THERE WILL BE OCCASIONAL SHRA THROUGH THE  
NIGHT, AND THE WIND WILL BE GENERALLY LIGHT THROUGH THE NIGHT.  
IFR WILL LIKELY BE LIMITED TO INSIDE THE SHOWERS. THERE IS A  
VERY SMALL CHANCE OF TS IN THE AREA OVERNIGHT, AND IN THE SE  
TUES BEFORE 18Z. HAVE NOT MENTIONED IT IN THE TAF YET DUE TO LOW  
CONFIDENCE OF OCCURRENCE. EXPECT THE LLWS TO NOT GO AWAY UNTIL  
CFROPA, THEN MECHANICAL MIXING WILL MAKE IT VERY GUSTY ON TUES.  
THE HIGHEST GUSTS WILL BE AT JST.  
 
COLD AIR WILL TURN THE LINGERING SHRA OVER THE W IN THE AFTN TO  
SHSN. SCT SHSN WILL THEN CONTINUE OVER THE HIGH TERRAIN OF THE  
WEST INTO WED.  
 
OUTLOOK...  
 
WED...AM SHSN POSSIBLE W MTNS.  
 
THU-SAT...NO SIG WX EXPECTED.  
 

 
   
HYDROLOGY
 
 
AFTER COORDINATION WITH LOCAL OFFICIALS, SOME CONCERN DOES STILL  
EXIST FOR MINOR FLOODING ALONG AND NEAR THE SUSQ BETWEEN YORK  
HAVEN AND SAFE HARBOR. THEREFORE, THE FLOOD WATCH FOR THIS AREA  
HAS BEEN EXTENDED INTO TUESDAY AFTERNOON. DUE TO THE MILD  
TEMPERATURES, THERE IS A POTENTIAL FOR ICE MOVEMENT, BUT THERE  
WILL ALSO BE DETERIORATION/THINNING OF THE ICE THROUGH TIME.  
ALL LOCATIONS ALONG RIVERS AND STREAMS THAT HAVE SIGNIFICANT ICE  
BUILDUP SHOULD MONITOR WATER LEVELS CLOSELY.  
 
THE ANTICIPATED RAINFALL TOTALS OF 0.5 TO 1.0 INCHES OVER THE  
NEXT 48 HRS IS MUCH LESS THAN WE HAD A FEW DAYS AGO, AND THE ICE  
IS LESS PERVASIVE/EXTENSIVE DUE TO OUR RELATIVELY MILD TEMPS  
(VERSUS THE PERIOD LEADING UP TO OUR PREVIOUS SIGNIFICANT  
RAINFALL). SO, NO OTHER AREAS WILL BE PLACED INTO FLOOD WATCH AT  
THIS TIME.  
 

 
   
CTP WATCHES/WARNINGS/ADVISORIES
 
 
FLOOD WATCH THROUGH TUESDAY AFTERNOON FOR PAZ065-066.  
 

 
 

 
SYNOPSIS...DANGELO  
NEAR TERM...DANGELO  
SHORT TERM...DANGELO  
LONG TERM...LAMBERT/RXR  
AVIATION...DANGELO  
HYDROLOGY...  
 
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