-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KCTP 212157
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
557 PM EDT MON JUL 21 2014

.SYNOPSIS...
A WEAKENING UPPER LEVEL TROUGH WILL SLIDE ACROSS PENNSYLVANIA
TODAY. A COLD FRONT WILL MOVE SOUTHEAST FROM THE GREAT LAKES AND
CROSS THE COMMONWEALTH LATE WEDNESDAY AND WEDNESDAY NIGHT. A
REFRESHINGLY COOLER AND LESS HUMID AIRMASS WILL OVERSPREAD THE
COMMONWEALTH FOR THE END OF THE WEEK INTO THE WEEKEND.

&&

.NEAR TERM /THROUGH TUESDAY/...
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REGIONAL RADAR LOOP SHOWING ISOLD CONVECTION DEVELOPING AS OF
21Z...PRIMARILY ACROSS THE LAUREL HIGHLANDS WHERE SPC MESOANALYSIS
ESTIMATES CAPES APPROACHING 2000 J/KG. ELEVATED HEAT SOURCE OF THE
ALLEGHENIES WILL BE THE PRIMARY FORCING MECHANISM THIS EVENING...AS
LG SCALE FORCING VERY WEAK. HAVE BUMPED POPS UP SLIGHTLY ACROSS
THE LAURELS/SC MTNS. OTHERWISE...STILL LIKE THE IDEA OF JUST SOME
ISOLATED SHOWERS POPPING UP OVR THE CENTRAL/NORTHERN MTNS WHERE
INSTABILITY IS RATHER MODEST. WEAK WINDS ALOFT WILL MEAN ANY
SHRA/TSRA WILL BE SLOW-MOVING AND COULD PRODUCE SPOT AMTS IN
EXCESS OF AN INCH. ACROSS THE LOWER SUSQ VALLEY...PERSISTENT MID
LVL CLOUDINESS SHOULD LIMIT ANY CONVECTION RISK AND RESULT IN A
DRY EVENING.

SCT PULSE-TYPE CONVECTION OVR THE MTNS SHOULD DIE SHORTLY AFTER
SUNSET. THE REST OF THE NIGHT SHOULD BE FAIR AND A BIT ON THE
MUGGY SIDE. A NEARLY CALM WIND AND DIMINISHING CU SHOULD ALLOW
TEMPS TO FALL CLOSE TO LATE AFTN DWPTS...PROMOTING AREAS OF FOG
LATE TONIGHT.
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&&

.SHORT TERM /TUESDAY NIGHT THROUGH 6 PM TUESDAY/...
TUESDAY WILL BE NOTICEABLY WARMER AND MORE HUMID WITH PARTLY
SUNNY SKIES. ONCE AGAIN WE WILL BE DEALING WITH THE POTENTIAL FOR
SOME DIURNAL CONVECTION. CAPES FCST IN THE 1000-1500J RANGE WILL
BE BATTLING INCREASINGLY WARM MID LEVELS TRYING TO CREATE
AFTERNOON SHOWERS AND T-STORMS. RIGHT NOW WE HAVE 20 POPS FOR THE
AFTERNOON...I AM STILL DEBATING DROPPING THAT ALREADY SMALL NUMBER
EVEN FURTHER GIVEN THE EXPECTATIONS OF THE WARMTH ALOFT PUTTING A
LID ON MOST ACTIVITY.

HIGH TEMPS TUESDAY WILL HAVE A REAL SUMMERY FEEL IN THE LOWER 80S
ACROSS THE MTNS...AND MID TO UPPER 80S THROUGHOUT THE VALLEYS OF
CENTRAL AND SOUTHERN PA.

&&

.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
OVERALL SCENARIO REMAINS UNCHANGED IN THE LONG TERM PERIOD AS A
LARGE UPPER RIDGE BUILDING OVER THE FOUR CORNERS REGION IS
FORECAST TO EXPAND NORTH AND EAST INTO THE ROCKIES AND PLAINS
DURING THE PERIOD. DOWNSTREAM...THIS WILL LEAD TO LONG WAVE
TROFFING OVER THE EASTERN THIRD OF THE COUNTRY. UPPER LOW TO THE
EAST OF HUDSON BAY WILL BE STRENGTHENED AT TIMES BY SHORTWAVE
ENERGY IN THE STRONGER JET STREAM FLOW ACROSS CANADA. SOUTHWARD
EXTENSION OF THIS LOW/TROF WILL AT TIMES DURING THE PERIOD
STRENGTHENING THE TROFFING ACROSS THE NORTHEASTERN U.S./OUR
REGION. TODAYS TREND OF MEDIUM RANGE MODEL GUIDANCE IS FOR
STRONGER/DEEPER TROFFING DOWNSTREAM ACROSS THE EASTERN
U.S...DEVELOPING AN ALMOST FULL LATITUDE TROF EXTENDING FROM THE
EASTERN CANADA LOW SWD TO FLORIDA. THIS WILL LIKELY SERVE TO
EXPAND AND PROLONG THE CHANCES FOR PCPN THIS WEEKEND.

GUIDANCE FORECASTS CONTINUE TO BRING A FRONT AND INCREASED
CHANGES FOR PRECIPITATION TOWARD PA IN THE WEDNESDAY/THURSDAY TIME
FRAME AND SHOW A SECOND...POTENTIALLY STRONGER SYSTEM LATE NEXT
WEEKEND. THE TREND OF STRONGER TROUGHING MENTIONED ABOVE HAS LEAD
TO SLOWER ARRIVAL AND DEPARTURE OF THE FRONTAL SYSTEM IN THE DAILY
PROGS. A WARM FRONT WILL BE ON THE DOORSTEP OF PA SUNDAY
MORNING...A BIT SLOWER THAN FORECAST YESTERDAY. HAVE THUS ADJUSTED
POPS/TIME TO SUIT. ASSOCIATED COLD FRONT DOES NOT CROSS THE
STATE TIL MONDAY AT THIS POINT...LEADING TO A POTENTIAL PROLONGED
PERIOD OF SHOWERS AND THUNDERSTORMS. AT THIS TIME FRAME
HOWEVER...A LOT WILL LIKELY CHANGE BEFORE WE REACH NEXT WEEKEND.

SURFACE HIGH PRESSURE AXIS TO OUR EAST WILL KEEP GENERALLY FAIR
WEATHER ACROSS PENNSYLVANIA THROUGH EARLY WEDNESDAY. A WARMING
TREND WHICH BEGAN TODAY...WILL CONTINUE RIGHT THROUGH WED...WHEN
TEMPS ARE EXPECTED REACH THEIR PEEK FOR THE WEEK IN THE IN THE
UPPER 80S TO AROUND 90F IN THE SUSQ VALLEY...AND GENERALLY IN THE
MID 80S ELSEWHERE.

&&

.AVIATION /22Z MONDAY THROUGH SATURDAY/...
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FEW SHOWERS NEAR BFD AND JST LATE THIS AFT.

21Z TAFS SENT.

EARLIER DISCUSSION BELOW.

LAST HOLDOUTS WITH MVFR CEILINGS ARE MY WESTERN
TERMINALS...BUT THEY WILL LIFT TO VFR AROUND OR SHORTLY AFTER
18Z...AND CONTINUE INTO THE EVENING HOURS.

A WEAK DISTURBANCE ALOFT COULD HELP TRIGGER AN ISOLATED SHOWER OR
THUNDERSTORM...OTHERWISE FAIR CONDITIONS WILL CONTINUE UNTIL MORE
PATCHY LOW CLOUDS AND FOG FORM ONCE AGAIN OVERNIGHT.

TUESDAY LOOKS LIKE A VIRTUAL REPEAT OF TODAY WITH ANY RESTRICTED
CONDITIONS IMPROVING DURING THE MORNING THROUGH MID DAY...ALONG
WITH THE POSSIBILITY OF ISOLATED SHOWERS AND THUNDERSTORMS IN THE
AFTERNOON.

OUTLOOK...

WED-THU...SLOW NW-SE MOVG COLD FRONT WILL LIKELY BRING REDUCED
CONDITIONS ALONG WITH SCT SHOWERS AND THUNDERSTORMS.

FRI-SAT...NO SIG WX.
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&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...LA CORTE
NEAR TERM...FITZGERALD/LA CORTE
SHORT TERM...LA CORTE
LONG TERM...LAMBERT/GARTNER
AVIATION...LA CORTE/MARTIN