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
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