Area Forecast Discussion
Issued by NWS State College, PA

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000 FXUS61 KCTP 221909 AFDCTP Area Forecast Discussion National Weather Service State College PA 309 PM EDT Wed Mar 22 2017 .SYNOPSIS... A parting shot of mid-winter cold through tonight before a more seasonable spring pattern returns temperatures to near or above normal levels through the end of March. A wintry mix remains possible early Friday morning before changing to rain. The weekend starts off very mild with rain likely by Sunday, and continued chances for showers early next week. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... Subsidence and drying clearly evident on the WV imagery with strong high pressure building in. Dewpoints over much of PA also have fallen into the single digits this afternoon. Cold/dry air continues to push into Central PA via gusty NNW winds (generally in the 25-30 mph range) in strong low level CAA. Temps peaking only in the mid 20s north to around 40 south, and when adding in wind chill effects today will feel on the order of 40 to 50 degrees colder relative to yesterday! The cold air is being supplied by a strong 1035+mb modified arctic high pressure system that is drifting across the Great Lakes to a position centered over Central PA by daybreak Thursday. The abnormally dry air coupled with clear skies and winds becoming light will result in a very cold night with minimum temperatures falling to near-record territory with single digits likely in the northern mountains and teens across the south. See the climate section for 3/23 minimum temperatures records. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/... After a cold start, temperatures will begin to rebound as low level flow veers to the south/southwest by midday Thurday across the west and mid afternoon in the east. Highs Thursday will be below average but it should feel noticably warmer with very light surface winds and plenty of late March sunshine bringing peak temps in the 40s. && .LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/... WAA pattern ramps up quickly Thursday night into Friday via anomalous west-southwest low level jet. Models continue to show pcpn spreading into marginally cold/retreating and relatively dry air near the surface between 06-12z Fri. Even with some evap cooling/wet bulb effects, hard to see thermal profiles supportive of snow unless the pcpn comes in very fast. Therefore went with rain, sleet or freezing rain wx/ptypes which fits WPC guidance. Ice accumulation will be hard to come by given temps near 32F, warm surfaces and climo but will show a few hundredths for storm total ice. Overall impact appears minimal but it only takes a small amount of ice to cause problems especially during the early morning commute. Temps should climb above freezing by mid morning Friday ending the risk for ice. Rain focus should shift north into NY Friday afternoon into Friday night as baroclinic zones sets up in upper level confluence zone downstream of deep cyclone moving through the Southern Plains. The boundary placement will be key to the fcst but it looks for now that most of the area will be in the mild warm sector. The models and ensembles continue to show a series of upper troughs progressing onshore from the Eastern Pacific and across the Southwest/South-Central Plains before deamplifying as they move east of the MS River. The first of 3 upper troughs emerges from the Southern Plains and crosses into the MS Valley Sunday and continues to weaken as surface frontal wave translates downstream crossing the OH Valley/Great Lakes into the northern Mid Atlantic states by Monday. Blend of NBM/ECENS/WPC still indicating max POPs in the Sunday-Sunday timeframe. Above average temperatures are expected over the weekend with the warmest day likely on Saturday with some sites approaching 70F over southern PA. Sunday should also be mild but a bit cooler due to the likelihood of rain. Fcst issues pertaining to a backdoor cold front appear to be confined to New England early next week with temperatures remaining near or or above climate averages into early next week. && .AVIATION /19Z WEDNESDAY THROUGH MONDAY/... Subsidence and drying clearly evident on the WV imagery with strong 1035mb high pressure building in. VFR conditions areawide with gusty NNW winds (generally in the 25-30 mph range) in strong low level CAA. These will taper off late this afternoon into the evening hours as center of high pressure moves directly over PA by Thu morning. VFR and light winds continue through Thursday, with high clouds increasing late. Outlook... Thu...No sig wx expected. Fri...Showers/reduced CIGS possible, mainly BFD. Sat-Sun...Showers/reduced CIGS possible. Mon...Showers/reduced CIGS possible west. && .CLIMATE... Minimum temperature records for 3/23 at select sites: MDT: 14 in 1934 IPT: 8 in 1906 BFD: 5 in 1959 AOO: 15 in 1960 && .CTP WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...RXR/Steinbugl NEAR TERM...RXR SHORT TERM...RXR LONG TERM...Steinbugl AVIATION...RXR CLIMATE... is the U.S. government's official web portal to all federal, state and local government web resources and services.