Area Forecast Discussion
Issued by NWS State College, PA

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387 FXUS61 KCTP 211655 AFDCTP Area Forecast Discussion National Weather Service State College PA 1255 PM EDT Sat Apr 21 2018 .SYNOPSIS... A large area of high pressure will control the weather throughout the weekend and into the beginning of next week. A gradual warming trend will ensue and allow temperatures to approach normal. A slow moving storm system will begin to affect the region by Tuesday. The good news is, no snow is expected this time around! && .NEAR TERM /THROUGH TONIGHT/... Lots of thin high clouds overhead, and they have been cutting the temp curve a little flatter than anticipated. The clouds will likely get thicker as more moisture spills over the ridge, but they should also slip a little to the south. Still, enough clouds to start calling it "cloudy" over the Laurels and SC Mtns tonight. Have nudged temps up just a deg or two there, and this should also keep any frost away. Would not even be surprised to see some radar returns/virga as a spot of enhanced lift moves along the PA/MD border later tonight. However, no need for a mention of sprinkles as it is so dry below 10kft. The longer conversation was over frost advy or not in the middle Susq. Light wind for sure. The clouds are the wild card. The SC Mtns and Lower Susq should be largely frostless tonight as either the clouds keep the temps up. Will just mention frost in fcst wx grids for the middle Susq and Ridge/Valley region between State College and Harrisburg, but not take the advy step. && .SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/... Another nice day is on tap for Sunday with highs expected to be a few degrees warmer than today. The high clouds should slink southward, but some cu may pop up in the Srn Mtns. Sun PM seems clear/fair again with even less of a worry for frost. && .LONG TERM /MONDAY THROUGH SATURDAY/... High pressure will control the pattern through Monday before we start to see the weather head downhill once again. Mornings will remain chilly, but afternoon temperatures will moderate close to seasonal normals with readings reaching the 60s in most places by Monday. The next weather maker is advertised to begin affecting the region on Tuesday and continue for much of the new work week. An upper low is just beginning to emerge out of the southern Rockies, and it will track east under the upper ridge that extends from the Midwest into Canada. As the low emerges onto the plains it takes on a sort of rex- blocky appearance as it crawls eastward, and latest model runs slow this system down from previous timing so grids adjusted accordingly. Models are in good agreement in eventually opening up this low as it moves into toward the east coast, reforming the long wave trough over the eastern US by the end of the week. The slow moving nature of the system suggests once the rain moves in, it will remain in the forecast for several days. The first of the rain looks to arrive during the day Tuesday with periods of rain continuing into Thursday. By later Thursday into Friday the GFS/GEFS start to disagree with the ECMWF/ECENS on the strength and timing of the lead shortwave. The GFS/GEFS suggest showery weather continuing for much of Friday while the ECMWF/ECENS suggest Friday will be dry and rather mild. Bigger disagreements arise for the weekend with the GFS showing a potent upper low and cold front that would be accompanied by an unseasonably cold airmass, and reintroduce the chance of snow showers in the cold blustery post cold frontal flow. That`s too far out to inspire real confidence and is just beyond the end of the untended forecast, so no mention of the S word is in the forecast as yet. High temperatures are expected to remain slightly colder than normal throughout the forecast period. But being only a few degrees below normal will feel relatively nice given the almost constant much below normal temperatures we have endured so far this month. && .AVIATION /18Z SATURDAY THROUGH THURSDAY/... Overall looking at dry and mild conditions into Monday, as high pressure builds into the area. No impediments to flight ops are forseen in the near term. A slow-moving storm seems like it will affect the area in the middle to latter part of the week. Outlook... Mon...No sig wx expected. Tue...Rain/low cigs becoming likely PM from S-N. Wed-Thu...Rain/low cigs. && .CTP WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...La Corte NEAR TERM...Dangelo SHORT TERM...Dangelo LONG TERM...La Corte AVIATION...Dangelo is the U.S. government's official web portal to all federal, state and local government web resources and services.