Area Forecast Discussion
Issued by NWS State College, PA

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000 FXUS61 KCTP 240803 AFDCTP Area Forecast Discussion National Weather Service State College PA 303 AM EST Sat Feb 24 2018 .SYNOPSIS... Periods of rain will continue through Sunday. The rain could be heavy at times Saturday afternoon across the southern half of Pennsylvania, and areawide Saturday night into early Sunday. A saturated ground and swollen streams will support an elevated risk for flooding through the weekend. A break in the wet weather pattern is expected early next week. Above average temperatures are expected to continue through much of next week before a relative cooling trend toward climatology into early March. && .NEAR TERM /THROUGH TODAY/... *Flooding possible this weekend* Cool and damp conditions prevailing this morning with widespread fog and areas of drizzle. Southwesterly breeze within a narrow warm sector has caused temps to warm into the mid 50s over the Laurel Highlands. Cooler air is working in from the west behind a cold front crossing the central mountains, but it will remain mild for a few more hours yet over the Laurels. Behind the front, boundary layer temperatures drop by about 10C overnight. in fact, any light precip that may occur across the NW mtns twd daybreak Sat could have a few sleet pellets mixed in. Mins sfc temps early Saturday will be in a rather tight range - from the mid 30s to around 40F across the northern half of the state, to the mid and upper 40s across the Laurel Highlands. && .SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/... The focus this weekend will be on potential flooding with additional rainfall amounts of 1-2 inches forecast over most of the area. The heaviest rainfall period/greatest risk for short- duration flooding should be Saturday night through early Sunday morning. The flood watch was expanded to include all of Central Pennsylvania through Sunday evening. Forecast rainfall and very wet antecedent conditions (very saturated ground/soils and much above normal streamflow/swelling streams) will support an elevated risk for longer duration, widespread flooding of small streams, creeks and river tributaries. Expansive low lying/poor drainage flooding is also possible. Temperatures will slowly climb into the mid 40s to low 50s on Saturday before peaking in the mid 50s and low 60s on Sunday based on multi model consensus blend. && .LONG TERM /MONDAY THROUGH FRIDAY/... The wet pattern looks like it will take a break during the first part of next week before precip risk increases next Wed-Fri. Model and ensemble guidance show a low pressure system tracking east-northeast from the TX/OK panhandle across the Central Plains/Midwest into the Great Lakes/Ohio Valley region by Thursday. The ECMWF/CMC solutions want to develop a secondary low to the south of PA from the southern Mid Atlantic piedmont to the coast while the GFS is much farther north with any secondary development. This may factor into some potential ptype issues or wintry wx but only something to watch at this range. Temperatures will continue to run above average next week with signs of trending cooler/closer to daily climate normals into early March. && .AVIATION /07Z SATURDAY THROUGH WEDNESDAY/... A bit of a mixed bag overnight into tomorrow. Low cigs across the region will bring widespread IFR conditions in low cigs and vsbys from fog across much of the airspace for the next 24 hours. However, the low cigs at BFD, JST and AOO, along with the persistent drier westerly flow will reduce the chances for temperatures to drop and thus weakening the chances for IFR vsbys. However, IFR cigs remain probable to form between 09Z to 12Z. Showers remain in Ohio and will slowly creep into the region by late Saturday morning, early Saturday afternoon. the IFR in cigs and vsbys through the central and eastern TAF sites will persist through Saturday, though there is a chance for a slight improvement in vsbys once the inversion at the SFC weakens Saturday afternoon. Rain will continue through the region through Saturday into Sunday. Outlook... Sat...Widespread restrictions with rain. Sun...Widespread restrictions likely in periods of rain. Mon-Wed...No sig wx. && .HYDROLOGY... Active hydrologic pattern ramps up again Saturday through Sunday. Recent snow melt and rainfall has soils quite wet. Streamflows are also running high. Forecast additional rainfall of 1-2 inches (with locally higher amounts possible across the mtns of Western PA) will produce significant rises and will need to monitor levels closely. Some poor drainage and small stream flooding is likely. && .CTP WATCHES/WARNINGS/ADVISORIES... Flood Watch through Sunday evening for PAZ004>006-010>012- 017>019-024>028-033>037-041-042-045-046-049>053-056>059- 063>066. && $$ SYNOPSIS...Lambert/Steinbugl NEAR TERM...Lambert/Steinbugl SHORT TERM...Lambert/Steinbugl LONG TERM...Steinbugl AVIATION...Ceru/Gartner HYDROLOGY... is the U.S. government's official web portal to all federal, state and local government web resources and services.