Area Forecast Discussion
Issued by NWS State College, PA

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000 FXUS61 KCTP 300640 AFDCTP Area Forecast Discussion National Weather Service State College PA 240 AM EDT Fri Sep 30 2016 .SYNOPSIS... Showery conditions will prevail through today, especially across the southern half of the state. Unsettled weather with occasional light rain showers will persist into the weekend with a gradual drying trend by early next week. && .NEAR TERM /UNTIL 8 AM THIS MORNING/... Two primary area of showers will continue through this morning, mainly across southern and eastern portions of the forecast area. The first plume of showers on a SE to NW axis across south-central PA and the Laurel Highlands coincided with a strong 45 kt serly LLJ, and enhanced upper level divergence/uvvel within the thermally direct cell associated with the right entrance region of a 90 kt/300 mb jet. The second area of mdt to hvy rain was being created by a similarly strong, nearly 4 sigma, 40-45 kt easterly 850 mb jet off the Atlantic transporting very high, 2-2.5 inch PWAT air over the coastal front. Heaviest rainfall rates of 4-8 tenths of an inch per hour per Dual Pol DPR product estimates are seen across the western Poconos and areas just east of the Lower Susq River. Latest HRRR tracks this area of enhanced rain NWWD across the Middle and West branch valleys of the Susq and north-central mtns during the mid to late morning hours. Across much of the remainder of central and northern PA, look for overcast skies with brief...scattered showers along with areas of drizzle and fog at elevations AOA 1800 ft MSL. Temps will be steady in the low-mid 50s across the western half of the state, and mid to upper 50s in the east, and will be steady or fall just a deg f or two early today. winds will persist from the east to northeast at 8-12 kts. && .SHORT TERM /8 AM THIS MORNING THROUGH 6 PM SATURDAY/... The Large low will be quasi stationary and will continue to stream moisture into Southwestern PA through much of today. Strong E-SE LLJ and above normal PW along with associated forcing on east/southeast side of upper low favors scattered to numerous lighter rain showers through the period across the Laurels. Elsewhere, the area of enhanced rain impacting the region form the Middle Susq Valley to the North-central Mtns early in the period with break up into generally scattered showers by the early afternoon hours today. Greatest rain chance this afternoon will once again be focused across the SE half of the state, but should be generally light and under 0.10 per hour, with 10-hour basin average amounts mainly under 0.25 of an inch. Greatest deep layer convergence appears to become focused across the western mtns of PA tonight and early Saturday...before shifting into Central PA for the late morning and afternoon hours Saturday. Expect to see rather low coverage of showers at any one time. However, a few narrow north-south bands of mdt showers should shift gradually east across the region during the day Saturday, bringing additional light 12-hour rainfall amounts of 2 tenths or less to many locations. A few locations could see over one half of an inch where an hour or so of training showers occur. Will follow cooler EC and NAM guidance for max temps ranging from the upper 50s across the mid 60s in the Susq Valley on Saturday. GFS MOS guidance looks to be up to several deg too warm considering solid overcast and persistent llvl easterly flow. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... The upper level low will continue to spin slowly northward into MI and continue on into Southern Canada. The low will slowly be pulled into the upper level flow and cold air advection will filter into the region early into next week. The final vestiges of the low that has dominated our weather pattern this week will finally lift and move off coast by mid next week by the upstream amplifying trough over the central CONUS. High pressure should regain control of the large scale pattern. The 12Z GFS comes more into alignment with the EC however the EC continues the path of the TC Matthew much slower and keeps it off the coast of Florida, where the GFS brings the projected path up the Atlantic coast and has the system nearing the NC coast by Thursday morning. Temperatures will be slightly below normal through the weekend, before shifting to slightly above normal by the middle of next week. && .AVIATION /06Z FRIDAY THROUGH TUESDAY/... Widespread MVFR-IFR conditions through tonight. Periods of rain moving SE-NW across the airspace early today with decreasing coverage by afternoon. Isolated LLWS possible 35-40KT from 090-120 degrees especially KBFD/KJST and may add with 09z update. Outlook... Sat...MVFR-IFR cigs. Ocnl -RA. Sun...MVFR cigs. Chc -RA. Mon-Tue...Gradual improvement likely. && .CTP WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Lambert/Steinbugl NEAR TERM...Lambert SHORT TERM...LAmbert LONG TERM...Ceru/Steinbugl AVIATION...Steinbugl is the U.S. government's official web portal to all federal, state and local government web resources and services.