Area Forecast Discussion
Issued by NWS State College, PA

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260 FXUS61 KCTP 242152 AFDCTP Area Forecast Discussion National Weather Service State College PA 552 PM EDT Sun Sep 24 2017 .SYNOPSIS... Unseasonable late-September heat will continue in central PA through early week. Mostly dry weather will also prevail with just an isolated shower possible in spots on Wednesday. A pattern change will bring cooler, fall-like weather back to the area for second half of the week and into the upcoming weekend. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... GOES-16 visible satellite loop shows scattered fair wx cumulus developing on the ridges early this afternoon. Widespread low to mid 80s as of 1 PM, making it feel more like summer than early fall. The humidity is also more noticeable with max HX values in the low 90s in many areas. Hourly temps climbed a little faster than fcst, but still no reason to deviate from persistence in this pattern in regard to high temps. It will be mild tonight with minimum temps running about +15 degrees above climate averages. Some fog in the valleys but otherwise clear. && .SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/... Areas of fog in the morning will give way to another very warm and muggy afternoon by late-September standards with max temperatures in the mid 80s to around 90F (+15-20 degrees above normal). It will feel even warmer with max HX values between 90 and 95 degrees. && .LONG TERM /TUESDAY THROUGH SUNDAY/... The blocking high that has been responsible for the recent extended spell of dry and anomalously warm conditions is forecast to start breaking down early this week, with shortwave energy sliding along the US-Canadian border finally chewing away at the high heights and bringing some cooler air eastward. In the meantime Maria is still forecast to drift northward into the offshore waters off of Cape Hatteras on Wednesday. But the aforementioned northern stream shortwave finally gives it the incentive to take a hard turn east as the storm passes 35 deg north. For our area, it looks like the first chance we will have to see any rain might be Wednesday with a weakening cold front that is destined to fall apart in the unfavorable shear on the northwest side of the sprawling hurricane. Any rainfall amounts look to be scattered and light, bringing little change to the dry conditions we`ve had around here for much of September. A bit more significant trough drops toward us for the end of the week into next weekend. The ECMWF looks a bit more potent but otherwise timing looks comparable between longer-range models. Not seeing much in the way of noteworthy precipitation again, with scattered light showers possible through this time. Biggest change will be that temps will drop off from our streak of well above-normal levels back toward seasonal normals by Friday. && .AVIATION /22Z SUNDAY THROUGH FRIDAY/...
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High pressure over the area will ensure VFR conditions and light wind through Monday over most of the area. The only concern will be patchy valley fog early Monday morning (mainly between 08Z-13Z). Based on a combination of SREF probability charts, MOS and conditional climatology, believe odds of IFR/LIFR reductions are near 50 pct at KBFD/KIPT, near zero at KJST, and somewhere in the 10-40pct range elsewhere. .Outlook... Tue...Patchy AM valley fog possible. Otherwise VFR conditions. Wed...Mainly VFR, isolated PM shower possible. Thu...No sig wx.
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&& .CLIMATE... Record-challenging late-September heat through early week. Daily high temperature records from 9/24 through 9/26: Bradford: 82* in 1961, 83 in 2007, 79 in 1998 Williamsport: 90 in 1961, 89 in 1970, 92 in 1900 Harrisburg: 97 in 1970, 93 in 1970, 91 in 1970 Altoona: 91 in 1970, 90 in 1970, 88 in 1998 *83F as of 1 PM && .CTP WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Steinbugl NEAR TERM...Steinbugl SHORT TERM...Steinbugl LONG TERM...RXR AVIATION...Fitzgerald/Steinbugl CLIMATE...

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