Area Forecast Discussion
Issued by NWS State College, PA

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000 FXUS61 KCTP 192009 AFDCTP Area Forecast Discussion National Weather Service State College PA 409 PM EDT Tue Sep 19 2017 .SYNOPSIS... A ridge of high pressure at the surface and aloft will stay locked in place over Pennsylvania for the next 7 days. This dominant weather feature will provide fair, warm and generally dry weather throughout this entire period. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... Though it took nearly half of the day to get started, clouds over central PA have rapidly eroded this afternoon - with the last patch of lower ceilings still hanging on over the Mid Susquehanna Valley at 2pm. Temps will again peak above normal in the upper 70s to lower 80s. The western extent of the outer bands of showers associated with slowly weakening Hurricane Jose look like they will just brush our SE zones late this afternoon, and we`ll continue to play it safe and keep mention of low pops and very low QPF (if any) of under one-tenth of an inch. Low level flow will become light and northerly tonight as Jose weakens to a Tropical Storm and continues to slowly drift off in a northeast direction. This will transition us away from the stratus we saw this morning back to locally dense valley fog for Wednesday morning. Min temps will be about 2-4F lower than early Tuesday over the northern half and similar to Tuesday for the southern half - and notably milder than normal. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/... After we burn off the fog in the valleys, a spectacular Wednesday is on tap with abundant sunshine and just a few flat cu and thin cirrus to paint the otherwise azure blue sky. Could be a couple of showers off to our SW in a very weak and eroding trough, but only result for us will be potentially an increase in cloud cover over the Laurel Highlands. Max temps will once again range from the upper 70s across the higher terrain of the north and west, to the lower 80s (and maybe a few mid 80s) in the southeast. && .LONG TERM /THURSDAY THROUGH TUESDAY/...
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Overall pattern hasn`t changed much, there is a good overall consensus in the models through the second half of the work week. For much of this period, a 590 dam closed 500 hPa high will drift slowly out of the midwest states, and become centered over western PA by late this weekend through early next week. The GEFS forecasts showed this feature as a closed 5880 m ridge over us with near +2 sigma above normal heights which will translate to well above normal temperatures. High temps from Wednesday and through the weekend will be 10-15F above normal with little or no chance of rain through at least Monday. Lows early each morning will be consistently in the mid and upper 50s across the northern and western mtns, to lower 60s in the larger SE metro areas. Min temps may cool off slightly for this weekend thanks to deep dry air and a light N to NW llvl flow of drier dewpoint air at the sfc.
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&& .AVIATION /20Z TUESDAY THROUGH SUNDAY/... MVFR Clouds over central PA have rapidly eroded this afternoon, with the last patch of lower ceilings still hanging on over the around SEG at 2pm. Otherwise, VFR conditions have become the rule. Winds are generally light, but over the Susq Valley speeds of 5 to 10 mph from the north are common. The western extent of the outer bands of light showers associated with slowly weakening Hurricane Jose look like they will just brush our SE zones late this afternoon, but coverage will remain too low to mention in LNS TAF. Low level flow will become light and northerly tonight as Jose weakens to a Tropical Storm and continues to slowly drift off in a northeast direction. This will transition us away from the stratus we saw this morning back to locally dense valley fog for Wednesday morning, which should catch many terminals outside of the Lower Susq Valley. .Outlook... Wed-Sat...Patchy valley fog possible each morning. Otherwise VFR with generally light winds and minimal clouds. && .CLIMATE... Astronomical Fall/Autumnal Equinox begins at 4:02 PM Friday September 22, 2017. && .CTP WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Lambert/RXR NEAR TERM...RXR SHORT TERM...RXR LONG TERM...Ceru/Gartner AVIATION...RXR CLIMATE...

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