360  
FXUS61 KCTP 141933  
AFDCTP  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE STATE COLLEGE PA  
333 PM EDT WED APR 14 2021  
   
SYNOPSIS
 
 
AN UPPER LOW OVER THE U-P OF MICHIGAN THIS AFTERNOON WILL DRIFT  
SLOWLY SE AND REACH PA AND NY LATER THURSDAY THROUGH FRIDAY. A  
COLD FRONT MOVING THROUGH ON THURSDAY WILL BRING COOLER THAN  
NORMAL TEMPERATURES FOR THE END OF THE WEEK. OCCASIONAL RAIN  
SHOWERS WILL KEEP IT DAMP. SOME SNOW WILL OCCUR ON THE HIGHER  
ELEVATIONS OF THE ALLEGHENIES AND LAURELS THURSDAY NIGHT WITH A  
LIGHT ACCUMULATION POSSIBLE BY DAYBREAK FRIDAY. TEMPERATURES  
WILL REBOUND TO NORMAL BY MONDAY.  
 

 
   
NEAR TERM /UNTIL 6 AM THURSDAY MORNING/
 
 
CENTRAL AND NW PA WILL RESIDE BETWEEN THE SUBSIDING BRANCHES OF  
TWO JET MAXIMA FOR MUCH OF THE OVERNIGHT HOURS TONIGHT. THIS  
WILL LEAD TO PARTLY CLOUDY SKIES ACROSS THE CENTRAL AND NW MTNS  
WHILE PLENTY OF LAYERED CLOUDS AND MAYBE EVEN A FEW LIGHT  
SHOWERS OCCUR ACROSS THE SOUTHER TIER COUNTIES.  
 
SFC COLD FRONT WILL ARRIVE ACROSS OUR WESTERN MTN ZONES WITHIN  
SEVERAL HOURS AFTER MIDNIGHT, BEFORE MOVING SE ACROSS THE REST  
OF OUR CWA.  
 
A DUAL TO MULTI-LAYER CLOUD DECK WILL SPREAD BACK INTO THE AREA  
LATE TONIGHT IN RESPONSE TO DEEP LAYER COOLING. HOWEVER, PRECIP  
AMOUNTS ACROSS MUCH OF THE REGION SE OF THE ALLEGHENIES WILL BE  
MINIMAL TO NIL PRIOR TO THU NIGHT WHEN THE COLDEST AIR ALOFT  
ARRIVES.  
 
LATER TONIGHT, A SHORT WAVE TROUGH SPINS IN AS THE FIRST REAL  
BOUT OF FORCING DEVELOPS ACROSS THE NW MTNS. THIS SHOULD TOUCH  
OFF SOME SCT SHRA IN THE NW, WHILE THE FAR EASTERN FRINGE OF THE  
CWA MAY STILL HAVE SOME --RA FROM THE DEVELOPING OFF- SHORE LOW  
NEARBY.  
 
LOWS TONIGHT WILL RANGE FROM THE UPPER 30S ACRS THE NW MTNS NEAR  
50F IN THE FAR SE.  
 

 
   
SHORT TERM /6 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/
 
 
THE UPPER LOW WILL BECOME LOCATED OVER LAKE ERIE/WESTERN NY ON  
THURS, AND THE ADVECTION OF THE MORE SIGNIF DRY/COLD AIR WILL  
INCREASE THURSDAY MORNING, AND CROSS THE CENTRAL AND EASTERN  
PART OF THE CWA IN THE LATE MORNING/AFTN.  
 
TEMPS WILL LIKELY SLIP A FEW DEGS F IN THE AFTN FOR THE WRN  
MTNS. NUMEROUS SHOWERS ARE EXPECTED TO DEVELOP, AND SOME  
REGRESSION/WWD MOVEMENT IS EXPECTED TO THE SYNOPTIC RAIN SHIELD  
OVER THE ERN THIRD OF THE STATE. THUS, WE COULD GET SQUEEZED  
WITH RAIN COMING IN FROM THE WEST AND EAST.  
 
925 MB WET BULB TEMPS WILL COOL OFF SIGNIFICANTLY DURING THE DAY  
THURSDAY AND WILL REACH JUST 1-3 DEG C ACROSS OUR WESTERN MTNS  
BY 00Z, BEFORE COOLING OFF BELOW ZERO AT NIGHT.  
 
WILL STAY WITH CONTINUITY AND THE LATEST NBM IN KEEPING THE  
SOUTH- CENTRAL MTNS GENERALLY DRY ON THURS. A RUMBLE OF THUNDER  
IS NOT OUT OF THE QUESTION ON THURS AFTN IN THE WEST UNDER THE  
COLDER AIR ALOFT AND WITH SOME SFC LIFT. HOWEVER, WE'LL LEAVE IT  
OUT FOR NOW WITH DEWPOINTS ONLY IN THE 30S. PERHAPS A LITTLE  
GRAUPEL?  
 
HIGH TEMPS THURSDAY WILL VARY FROM THE MID-UPPER 40S ACROSS THE  
NW MTNS AND LAUREL HIGHLANDS TO THE LOW 60S IN THE FAR SE.  
 
NW WINDS WILL INCREASE WITH MDT GUSTS INTO THE MID TEENS TO  
AROUND 20 KTS BY LATER THURSDAY AFTERNOON ACROSS THE CENTRAL AND  
WESTERN ZONES.  
 

 
   
LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/
 
 
FOR THURSDAY NIGHT, THE COASTAL SURFACE LOW DEEPENS WELL  
EAST/NORTHEAST OF CENTRAL PA BUT THERE WILL CONTINUE TO BE  
SHOWERS AROUND AS THE UPPER LEVEL LOW MOVES ACROSS PA. WE  
CONTINUE WITH CHANCE AND SLIGHT CHANCE POPS FOR MAINLY RAIN  
SHOWERS THURSDAY NIGHT. ENOUGH COLD AIR COULD SNEAK IN TO MIX  
RAIN WITH WET SNOW FROM THE NORTHERN MOUNTAINS TO LAURELS. QPF  
AMOUNTS ARE MINIMAL AT THIS TIME, WITH ONLY A FEW HUNDRETHS OF  
AN INCH EXPECTED. THEN FOR FRIDAY, SOME WRAP AROUND MOISTURE  
WILL BE PREVALENT BUT WILL DRY UP SOME AS THE UPPER LEVEL LOW  
DEPARTS WELL TO THE EAST OF SOUTHERN NEW ENGLAND IN TANDEM WITH  
THE COASTAL SURFACE LOW.  
 
THE BALANCE OF THE MEDIUM RANGE GUIDANCE CONTINUES TO SUPPORT  
FAIR AND SEASONABLE WEATHER FRIDAY NIGHT INTO SATURDAY, AS UPPER  
LEVEL RIDGING BRIEFLY BUILDS OVER THE REGION BETWEEN DEPARTING  
UPPER LOW AND UPSTREAM TROUGH OVER THE WESTERN GREAT LAKES.  
 
THE LATEST GFS AND EURO AGREE FAIRLY WELL FOR THE MID AND LONG  
RANGE, WITH SHOWERY WEATHER LIKELY, AS A PAIR OF LEAD  
SHORTWAVES LIFT OUT OF THE OHIO VALLEY SUNDAY/MONDAY, THEN A  
DEEPENING UPPER TROUGH OVER THE GREAT LAKES PIVOTS INTO THE  
REGION TOWARD THE MIDDLE OF NEXT WEEK. THIS WILL LIKELY BRING  
PRECIPITATION ASSOCIATED WITH THE COLD FRONT. MOST OF IT WILL BE  
RAIN, BUT THERE IS A CHANCE FOR SOME SNOW FLURRIES IN THE  
NORTHWEST AS THE FRONT MOVES OUT OF THE REGION ON WEDNESDAY  
MORNING.  
 
WHILE SOME DETAILS OF TIMING REMAIN UNCERTAIN, THE WET PATTERN  
LOOKS TO CONTINUE NEXT WEEK. MOISTURE MAY BE MINIMAL, SO  
PRECIPITATION AMOUNTS LOOK FAIRLY LIGHT.  
 

 
   
AVIATION /19Z WEDNESDAY THROUGH MONDAY/
 
 
WIDESPREAD VFR WILL PREVAIL FOR THE REST OF TODAY, EVEN ACROSS  
THE SOUTHERN TIER COUNTIES OF PA (THAT WILL BE BRUSHED BY AN  
AREA OF LIGHT RAIN WITH ITS AXIS ABOUT 50-75 NM SOUTH OF THE  
MASON-DIXON LINE), AND WILL CONTINUE TO HAVE A THICK LAYER OF  
MAINLY MID-LEVEL CLOUDS.  
 
ACROSS THE CENTRAL ZONES, IMPROVING CONDITIONS (SKY COVER-  
WISE) WITH PARTLY TO MOSTLY SUNNY SKIES WILL OCCUR/OR DEVELOP  
THIS AFTERNOON. WINDS WILL BE LIGHT.  
 
VARIABLE AMOUNTS OF CLOUDS WILL OCCUR LATER TONIGHT, AFTER A  
MAINLY CLEAR EVENING ACROSS THE NW HALF OF THE STATE THROUGH  
04Z.  
 
OUTLOOK...  
 
THU...PERIODS OF RAIN OR SHOWERS/LOW CIGS POSSIBLE, ESPECIALLY  
EASTERN PA AND OVER THE WRN MTNS. GENERALLY LOW-END VFR TO  
PERHAPS SCATTERED MVFR THROUGHOUT THE CENTRAL RIDGE AND VALLEY  
REGION.  
 
THU NIGHT...MAINLY VFR WITH SCATTERED RAIN/SNOW SHOWERS NEAR THE  
ALLEGHENY FRONT, WITH MAINLY IFR AND MORE FREQUENT SNOW SHOWERS  
OVER THE NORTHERN MTNS OF PA AND LAUREL HIGHLANDS.  
 
FRI...AM LOW CIGS POSSIBLE W MTNS.  
 
SAT...NO SIG WX EXPECTED.  
 
SUN...LOW CIGS POSSIBLE IN SCATTERED SHOWERS.  
 

 
   
CTP WATCHES/WARNINGS/ADVISORIES
 
 
NONE.  
 

 
 

 
SYNOPSIS...LAMBERT/DANGELO  
NEAR TERM...LAMBERT/DANGELO  
SHORT TERM...LAMBERT/FITZGERALD/DANGELO  
LONG TERM...FITZGERALD/GUTIERREZ  
AVIATION...LAMBERT/COLBERT  
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

The Nexlab PA Page Main Text Page