Area Forecast Discussion
Issued by NWS State College, PA

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000 FXUS61 KCTP 292129 AFDCTP Area Forecast Discussion National Weather Service State College PA 529 PM EDT FRI JUL 29 2016 .SYNOPSIS... An upper level trough will influence the region through early next week...bringing daily chances of scattered showers and thunderstorms. Most of the time will be dry in any one location however. high pressure will build over the northeastern united states by mid to late next week. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
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Dying cold front pushing into northern Pa early this evening, producing enough lift to support sct convection ovr the northern counties at 21Z. Latest CAMS indicate focus for dwindling convection will shift into the central counties toward sunset as outflow bndry pushes south. Nocturnal cooling and lack of sig forcing should result in nearly all the leftover showers dissipating by midnight. Focus will then shift toward shortwave approaching from the Grt Lks. Latest guidance supports an increasing chc of showers assoc with this feature ovr the western counties arnd dawn. Low tonight mainly in the 60s some warmer spots in southeast and cooler in northwest.
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&& .SHORT TERM /6 AM SATURDAY MORNING THROUGH 6 PM SATURDAY/... Most guidance continues to show the plume of high PW air coming into PA Saturday. This favors increased chance of showers and thunderstorms. Each hydrostatic model and it`s convective parameterization scheme (CPS) have a different idea on the evolution. The high PW air and SW flow favors the chance of rain. The 12Z NAM maybe a excessive later Saturday into Sunday. At this time the GEFS 0.5 degree data implies the chance of rain increases rapidly after 11 AM Saturday and keeps climbing. It of course has a big wet bias in convective cases. The GEFS and all the blends imply lowest PoPs in northwest and west and higher central to eastern areas. GEFS is basically showing rain over all of eastern and central PA by 21Z. Expect showers and thunderstorms with areas affected by intense cores to see some better rainfall amounts. Most areas should not see the widespread 0.5 to 1.0 inch amounts. The rainfall peaks in the SREF/GEFS shortly after the CAPE peaks. This implies mostly convective and CPS is biasing forecasts. The most intense rainfall is forecast mainly after 21Z and early overnight Saturday which is mainly in the next forecast period. && .LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...
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Shortwave moves across PA Saturday night triggering showers and possibly a thunderstorm. As that passes to the east, there should be a break and then the main trough moves through with some scattered convection likely late Sunday and Sunday night. Do not believe it will be as wet as earlier advertised by models. Diminishing POPs into Monday as the upper level trough and cyclonic flow slowly exits off the coast. Big ridge builds over the central US and moves east to Ohio by Friday. This puts us into a drier pattern with NW flow. May see something move over the ridge but then drop to the west and south of PA. Can`t rule out some afternoon clouds popping and maybe an isolated convective cell over the higher terrain but that should be it. Temperatures will start out in the normal range and warm toabove normal toward the end of the week.
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&& .AVIATION /21Z FRIDAY THROUGH WEDNESDAY/... VFR all about the air space. Issues this afternoon include some very isolated rogue showers in central PA and more organized showers in northwestern PA. Check radar before takeoff as some of these showers will develop into thunderstorms. Models imply rain and showers move in Saturday into Saturday night. Shower with lower visibility and ceilings along with isolated thunderstorms will be an issue from about midday Saturday through midnight. Then more IFR in patchy fog where it rains. OUTLOOK... SAT...Showers and isolated TSTMS IFR/MVFR then overnight fog. SUN-Mon...Scattered showers and isolated thunder. TUE...Improving conditions. && .CTP WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...DeVoir/Fitzgerald NEAR TERM...Grumm/Fitzgerald SHORT TERM...Grumm LONG TERM...Watson AVIATION...Grumm is the U.S. government's official web portal to all federal, state and local government web resources and services.