810 FXUS61 KCTP 091813 AFDCTPArea Forecast Discussion National Weather Service State College PA 213 PM EDT Thu Oct 9 2025
.SYNOPSIS... * Frost/freeze conditions could end the growing season across parts of central PA tonight through daybreak Friday * Crisp and pleasant Fall weather to end the week with increasing clouds Friday night * Columbus Day weekend starts dry and likely ends wet with heavy rain and gusty winds possible over eastern Pennsylvania
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.NEAR TERM /THROUGH TONIGHT/... Clear and cold tonight with widespread frost/freeze conditions expected. Min temps in the 25-40F range are 5 to 15 degrees below the historical average. This may end the growing season in parts of central PA (PNS will be sent later Friday morning). A frost advisory and freeze warning remains in effect from 11PM this evening to 9AM Friday.
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.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... Chilly and frosty start Friday followed by lots of sunshine with highs in the 55-65F range or +/- 5 degrees either side of climo. A bit warmer on the margin vs. Thursday. Low clouds may reach the Lower Susquehanna Valley by Friday afternoon/evening with a general increase in cloud cover across all of CPA Friday night into Saturday. A relatively milder/moist east to southeast flow will result in a much warmer (+7-15F) [Friday] night with more seasonable low temps in the 35-50F range. Hires model data even suggest potential for ridge-shrouding fog and pockets of BR/DZ.
Compact closed upper low over lower MI will interact and merge with Carolina coastal storm on Saturday. Large scale lift and anomalous easterly flow (-3SD @850mb) will result in a steadily increasing opportunity for rain during the day with widespread rain/low clouds/drizzle by Saturday night. Max/min temps trend milder with the largest 24 change to low temps +10F warmer vs. Friday night.
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.LONG TERM /SUNDAY THROUGH THURSDAY/... A strengthening coastal low pressure system will move slowly north along the Mid Atlantic (Delmarva/NJ) coast Sunday into Monday. Very strong easterly/onshore flow (up to -4SD@850mb) could bring heavy/soaking rain bands to parts of eastern PA. Primary impacts at this juncture would be a somewhat limited risk of flooding along with potential for wind gusts >35 mph. We continue to highlight the heavy rain/wind risk in the HWO particularly over the Lower Susquehanna Valley.
The phased upper level system and coastal low are projected to track eastward Tuesday, bringing and end to the rain. Breezy conditions may persist into midweek as p-gradient remains fairly tight with high pressure drifting southeast from the Great Lakes. Expect an improving/drying trend on balance with seasonal cooling trend Tue-Thu.
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.AVIATION /18Z THURSDAY THROUGH TUESDAY/... Widespread VFR conditions prevail through Friday afternoon under mainly clear skies. Odds for sub-VFR ceilings will increase over the southeast airfields by Friday as low level easterly flow increases to the north of Carolina coastal low pressure.
Outlook...
Fri...VFR.
Sat-Mon...Low clouds and rain/wind potential increasing particularly over the southeast airfields.
Tue...Continued breezy with rain ending/clouds breaking with gradual improvement.
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.CTP WATCHES/WARNINGS/ADVISORIES... Freeze Warning from 11 PM this evening to 9 AM EDT Friday for PAZ004>006-010>012-017>019-024>028-033>037-041-042-045-046- 049>053-056-058-063-064. Frost Advisory from 11 PM this evening to 9 AM EDT Friday for PAZ057-059-065-066.
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SYNOPSIS...Steinbugl NEAR TERM...Steinbugl SHORT TERM...Steinbugl LONG TERM...Steinbugl AVIATION...Steinbugl
NWS CTP Office Area Forecast Discussion