Area Forecast Discussion
Issued by NWS State College, PA

Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
-- Remove Highlighting --
-- Discussion containing changed information from previous version are highlighted. --
000 FXUS61 KCTP 252221 AFDCTP Area Forecast Discussion National Weather Service State College PA 621 PM EDT Tue Oct 25 2016 .SYNOPSIS... Changable weather - some of it winter-like - is in store for the region. One weather system arriving late Wednesday night which will bring rain to most of the area and some mixed precipitation to the north. After the cold front goes by, the cold northwest flow returns for a day or two. Another system is slated to affect the area over the weekend, but should be milder than this first one. Temperatures should average near to slightly below normal with some moderation likely into early November. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... Clouds are getting a big hole in them right now with the cloudiest areas the ones with the dual-lake fetches (Georgian Bay+wrn LO and LH+LE). Some increase in 8h temps is fcst for the NW third for the evening, but most of the clouds should disappear after midnight. The NE countiees have the lowest chance of clearing totally due to flow off LO perhaps lingering clouds there. The wind should begin to abate as we lose the heating and by a few hours after sunset it will be light and variable or plain calm. This will set up a good radiational cooling scenario and the Freeze Warning and going mins look fine. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/... Wx grids have many more colors on them Wed night than they have for many months. Most of Wed will be a decent day with a mostly sunny start. High clouds will move in from the west in the afternoon. The high/mid clouds will be getting fairly thick across most of the area by sunset, but there is only a miniscule chance of a shower/sprinkle in the far W before 10PM. The thickening clouds and light SE wind will help keep temps near normal - that is - above freezing in the south and valleys, and around or slightly below freezing in the north. After midnight, a cold rain is forecast to slide quickly w-e across the northern tier as the low approaches and upper trough digs a little over the Upper Great Lakes. Rain will likely make it into the central third of the state, and probably into the Laurels. But, the SErn part of the CWA could stay dry for much of the night. Now, for the ?fun? - Precip type issues arise across the northern tier where temps at the sfc and in the lower 6kft get sub-freezing at different times during the night and early Thurs morning. Right now, the soundings and SREF probabalistic p-type data all point to a mix of rain and sleet falling at first as the precip begins in the NW - but it then turns to rain in Warren and much of McKean Co. The NErn counties will have the sleet/snow-favorable profile for much of the night and into the daylight hours Thursday. This looks very much elevation-dependent, as most October events are. The ground temps are still rather warm, but time of day/night is favorable for accums to occur (no solar heating). Will paint in all the precip types but freezing rain for now in the NE for 6-9 hours. QPF could reach more than a half of an inch in the north - and frozen precip (read: snow and sleet) accumulations will push 2 inches on the highest ground. Much of the area will pick up an inch or so of the mixed frozen stuff. Might be an interesting transition and mix of flakes, needles, sleet pellets, etc. as the event unfolds since the model soundings show wild mixing of different intrusions of warm and some cooling at varied times. Again, most of the southern two-thirds of the area will have no chance for frozen precip. && .LONG TERM /THURSDAY THROUGH TUESDAY/... Low pressure center will move across the Lake Erie area thursday with warm advection across central PA. Mixed precipitation in the morning in the northeast will change over to rain. The southern areas will break into the warm sector earlier in the day with precipitation becoming scattered showers. Associated cold front will sweep across PA Thursday evening with colder northwest flow and maybe some lake-effect showers overnight mixing again with some snow in the higher elevations across the central northern tier. Flow changes during the day as winds begin to veer already in advance of the next system approaching the Great Lakes. So brief high pres ridge across Central PA Friday. This next system looks to track a bit further north giving us a warming trend. Northern tier may see some precip as the warm front pushes northeast. Southern areas will be mild and relatively dry. Another dry period will likely follow the weekend system with signs of a warming trend into the first week of November. && .AVIATION /21Z TUESDAY THROUGH SUNDAY/...
-- Changed Discussion --
Skies are scattering out as drier upstream air begins to work into the region. Much of the area will be clear to scattered with widepsread VFR conditions expected. Some patchy late night fog is possible - mainly along/in the river valleys, but the airmass is dry. Wed will be VFR ahead of a storm system that will be moving into the lower great lakes by late in the day. A warm front will lift north into the area Wednesday night and Thursday bringing widespread reduced conditions. Outlook... Fri...AM shrasn/low cigs possible W Mtns. Sat...SHRA w/IFR CIGs possible N PM. Otherwise no sig wx. Sun...SHRA w/MVFR cigs N and W. Breezy NW wind.
-- End Changed Discussion --
&& .CTP WATCHES/WARNINGS/ADVISORIES... Freeze Warning from 2 AM to 9 AM EDT Wednesday for PAZ026>028- 035-036-045-046-049>053-056>059-063>066. && $$ SYNOPSIS...Dangelo/Steinbugl NEAR TERM...Dangelo SHORT TERM...Dangelo LONG TERM...Watson AVIATION...Dangelo/La Corte is the U.S. government's official web portal to all federal, state and local government web resources and services.