099 FXUS61 KCTP 111042 AFDCTP Area Forecast Discussion National Weather Service State College PA 642 AM EDT Fri Apr 11 2025 .SYNOPSIS... *Cloudy, chilly and wet end to the week/start to the weekend *Drying out Sunday with some sun and milder temperatures *Warmer with late-day rain showers Monday followed by windy and cooler weather next Tuesday and Wednesday && .NEAR TERM /THROUGH TONIGHT/... A moist southeast flow will maintain widespread low clouds and areas of light rain/drizzle/ridgetop fog early this morning especially over the western Alleghenies -- where T/Td spreads are less than 2 degrees and moisture convergence is maximized along an inverted sfc trough extending NWWD from sfc low developing in eastern NC. A deep layer 500mb trough evolving over the eastern Great Lakes southward into the central Appalachians will amplify over the Mid Atlantic region today as an jet streak rounds the base of the trough and lifts northeastward along the coastal plain. Max QPF response tied to favorable left exit region jet dynamics and strengthening fgen forcing on the NW side of developing sfc low along the VA/NC coast will be across the southeastern zones with 0.75-1+ inch rainfall totals fcst near and southeast of I81. Latest HREF indicates highest probability for >1" is near and southeast of US30 corridor in Adams/York/Lancaster County. Light rain/drizzle will continue over the northwestern half to 2/3 of the forecast area through tonight with QPF totals of less than 0.50 inches. Thermal profiles tonight will be cold enough to support a rain/wet snow mix over the higher elevations in the northeastern quadrant of the forecast area, but sfc temps above 32F suggest any slushy coating <0.5" will be limited to non- paved sfcs. Cold air damming, combined with low clouds and rain, will result in a very chilly end to the week by mid April standards with highs in the mid 40s or 8 to 15 degrees below the historical average. && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... As the surface low tracks from the DelMarVa off the coast, the llvl flow will back to the north. While QPF amounts will trend substantially lower on Saturday (<=0.10"), residual wrap around moisture within the cold conveyor belt/TROWAL on the northwest periphery of the closed upper low will result in another chilly and damp day across CPA to start the second weekend of April. We trimmed daytime maxTs a bit in response to this cool pattern setup. Precip tapers off from NW to SE Saturday night. However, low clouds are likely to get trapped beneath the subsidence inversion associated with high pressure building into CPA into early Sunday morning. Min temps will be similar to Friday night in the 35-40F range. More seasonable weather is expected on Sunday with a mix of sun and clouds as high pressure migrates over the Keystone State. Max temps are projected to climb by +10-15 degrees vs. Saturday with highs in the 50-60F range or very close to daily climo. A warm front lifting northeast from the Ohio Valley could provide more clouds than fcst especially into Sunday night and maybe even some light rain showers over southwest PA. Lows also trend warmer vs. Saturday night with the largest MinT24hrChange of +5 to +10F across the western mtns where southerly return flow will be most active into Monday. && .LONG TERM /MONDAY THROUGH THURSDAY/... A return southwest flow between the exiting surface high and an approaching cold front over the Grt Lks should result in a warm Monday with maxtemps several degrees above climo. The fast-moving cold front is progged to sweep across central PA Monday afternoon/evening, accompanied by a round of showers for most of the area. Strong large scale forcing and decent moisture return support high POPs but relatively low QPF per the latest EPS plumes (ensemble mean qpf 0.1-0.4 inches) A digging upper trough over the E Grt Lks will then likely be accompanied by blustery conditions into midweek with temperatures falling well below mid April normals by Wednesday. The arriving airmass should be sufficiently cold to produce lake effect rain and snow showers over primarily the Allegheny Plateau into early Wed. Fair and seasonable weather looks likely next Thursday, as the deep upper trough lifts out and surface ridging arrives. However, an approaching warm front could potentially spread showers into the region by Thursday night. && .AVIATION /12Z FRIDAY THROUGH TUESDAY/... Isolated rain showers continue to pop up across the region, their impacts sporadic given the light precipitation and are mainly progressing over western Pennsylvania this morning. A mixture of IFR and MVFR is currently being observed across all airfields. A thick cloud deck is expected to persist overhead for the entire day, keeping skies overcast with low ceilings. A near stationary front parked in western Pennsylvania and draped over the Ohio Valley, along with the associated surface low, will continue to keep the region supplied with abundant moisture throughout the day today. More scattered showers are likely across much of the state throughout the morning and into early afternoon. Rain will increase in spacial coverage across the Lower Susquehanna Valley sites of MDT and LNS by late afternoon today, with steady rain likely to persist beyond 00Z Saturday. Little to no improvement to flight categories is expected for the next 24 hours. Outlook... Fri-Sat...Periods of rain with sub-VFR likely. Sun...Improving conditions/trending VFR. Mon...VFR. Clear early. Increasing clouds late. Tue...Sct rain throughout the day. Sub-VFR possible. Wed...Iso snow in NW. Elsewhere VFR/no sig wx. && .CTP WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Steinbugl NEAR TERM...Fitzgerald/Steinbugl SHORT TERM...Fitzgerald/Steinbugl LONG TERM...DeVoir/Fitzgerald AVIATION...Bowen