Area Forecast Discussion
Issued by NWS State College, PA

Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
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. --
121 FXUS61 KCTP 231909 AFDCTP Area Forecast Discussion National Weather Service State College PA 309 PM EDT Mon Apr 23 2018 .SYNOPSIS...
-- Changed Discussion --
A slow moving area of low pressure will begin to affect the region overnight, and the weather will remain unsettled for most of the upcoming workweek. Behind this system, an upper level trough will set up over the eastern U.S. bringing the potential for showers and a continuation of below normal temperatures into next weekend.
-- End Changed Discussion --
&& .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
-- Changed Discussion --
SE flow very gradually moistening up the boundary layer this afternoon as surface high slides off the East Coast. Dewpoints have climbed into the 30s even with mixing layer up to around 5000ft. Maxes will peak in the upper 60s most locales. There is some haze being reported at KSEG at 19z - this is from a plume of smoke from a prescribed burn in Dauphin County. Rain will likely reach my SWRN zones around or just before midnight and continue to slowly spread NE into the Central Mountains through Tuesday morning. Lows fall into the 40s tonight, with upper 30s along the northern and northeast counties.
-- End Changed Discussion --
&& .SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/...
-- Changed Discussion --
A slow moving upper low will crawl eastward on Tuesday, reaching the central Appalachians/SRN Ohio Valley by Tuesday evening. With the upper low weakening, the surface reflection is progged to be a rather anemic low which will lead to a forecast of high POPs but generally light QPF. Worded forecast for periods of mainly light rain overspreading the entire forecast area before the day is over. Temps will stay cool as the light precip adiabatically cools the lower levels, so highs will struggle just into the 50s. Main area of precip swings across mainly eastern sections Tue night keeping PoPs high before tapering off from west to east overnight. Another upper low reinforces showery weather heading into Wed.
-- End Changed Discussion --
&& .LONG TERM /WEDNESDAY THROUGH MONDAY/... The pattern is expected to become complex and unsettled as the upper low opens up and begins to shear out through the Mid Atlantic states. A series of waves upstream are made to reinforce and help develop a large scale trough over the eastern US as we move through late week and into next weekend. The details start to diverge as early as Wed when the EC/ECENS follow the lead shearing shortwave with a potent closed upper low that is made to move through the area Thursday with showers for most of the CWA. The GFS/GEFS show a flat upper ridge traversing the region yielding a dry and mild day. I looked at the GEFS and leaned closer to the SuperBlend POPs which show a dry Thursday afternoon. By Friday, the old differences remain with the EC products making for a dry mild day, and the GFS families suggesting at least a small chance of showers. It all leads to a low confidence forecast as we move into the extended range. The latest guidance does agree that it will be cooler over the upcoming weekend as the upper trough slides east. Good to note the NAEFSBC hustles the weekend trough east bringing a fast return to rising heights and milder air for next week. && .AVIATION /19Z MONDAY THROUGH SATURDAY/...
-- Changed Discussion --
SE flow very gradually moistening up the boundary layer this afternoon as surface high slides off the East Coast. But VFR conditions are the rule areawide, except at KSEg which is reporting some haze from a plume of smoke from a prescribed burn in Dauphin County. Conditions begin to deteriorate tonight from the SW as restrictions begin to slide across the area. Biggest impacts will be over the Laurel Highlands tonight and the western half much of Tuesday before working into the east later in the day. Rain will likely reach SWRN zones around or just before midnight and continue to slowly spread NE into the Central Mountains through Tuesday morning. Bukfit soundings indicate there will be southeasterly gusts of 15-20kts this afternoon in the vicinity of KJST/KAOO, with slightly lighter winds further north and east. Winds pickup again on Tue. Outlook... Tue...Rain/low cigs becoming likely. Wed...AM rain/low cigs likely, then improving. Thu...AM low cigs possible W Mtns. Fri...PM showers/cig reductions possible, mainly west. SAT...Showers/cig reductions possible, mainly NW.
-- End Changed Discussion --
&& .CLIMATE... As of midnight Sunday night, April 2018 is in the top 10 coldest on record. While milder conditions are expected this week, it would take several abnormally warm days to turn the trend around. && .CTP WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...RXR NEAR TERM...RXR SHORT TERM...RXR LONG TERM...La Corte AVIATION...RXR CLIMATE...

USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.