Area Forecast Discussion
Issued by NWS State College, PA

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574 FXUS61 KCTP 261141 AFDCTP Area Forecast Discussion National Weather Service State College PA 741 AM EDT THU MAY 26 2016 .SYNOPSIS... A ridge of high pressure will set up shop over the western Atlantic for the next several days bringing warm and increasingly humid conditions to the region into the holiday weekend. Cooler and showery weather may arrive for Memorial Day. && .NEAR TERM /UNTIL 7 PM THIS EVENING/... High and mid clouds cover the area right now and some sprinkles likely falling out of the 10kft clouds. A better shower is headed right for KBFD, but is working into 50F dewpoints. The winds should be picking up from the south as the morning continues and we get some mixing. The air is still fairly dry but is moistening up slowly. Dewpoints are now mainly in the 50s but no 60s yet. The clouds will create problems in the forecast for afternoon and evening convection. The thickest patch of the mid clouds should move across the fcst area W-E this morning before breaking up a bit in mid-day. Peak heating should be coincident with a weak upper shortwave which will slide across the region. This combo should allow for cells to grow tall enough to produce thunder. The amount, intensity and location of showers and thunderstorms will depend highly on the amount of low level heating we can achieve through the cloud cover. The highest POPs will be placed over the Alleghenies where the elevated heating surfaces and proximity to the best forcing will compliment each other. There may still be a weak mid-level capping inversion in the morning. But, CAPEs are progged to get rather fat in the afternoon = 500 to 1100J/kg. The low shear environment will mean there will be little organization to the showers/storms. SPC does not even put us in the marginal risk. PWATs will be in the 1.25-1.5 inch range and the warm-cloud layer more than 10kft deep today. There could be some heavy rainers since they will be moving slowly - but at least they will be moving today. High temps should be a few degrees lower than Wednesday for most places due to the cloud cover. The NW mountains may not get to 80 degrees. && .SHORT TERM /7 PM THIS EVENING THROUGH 6 PM FRIDAY/... Precip chances get much lower after sunset, but a few cells may survive until close to midnight. Then the light wind overnight could allow for fog to form as the moisture/dewpoints will be much higher than the last few nights - especially after many places have some rain on Thursday. While there should be a lull in the showers later tonight and Friday morning, the CAPE gets high again in the afternoon - possibly much higher (maybe twice) than Thursday. However, even with CAPEs in the 2000J/kg range, the models generate only scattered convection. This may have more to do with a lack of forcing as there is no short wave to help convection along. Will hold the course with 30-40 POPs at this point with the better chance for a shower over the ridges. Once again, the showers should pop up over the mountains first - but may just rain themselves out of existence with almost no shear at all. What rain does fall could be heavy with almost zero storm motion and PWATs will still be above 1 inch. && .LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/... The large scale pattern has a decidedly summertime look and feel to it through the Memorial Day weekend and into next week with light winds aloft and a prevailing ridge across the northeast CONUS. Temperatures will average above normal with the core of the `hot` weather front-loaded Friday-Sunday before trending modestly toward late May/early June climatology. Precipitation risk early in the period should be characterized by diurnal convection with the highest probs occurring during peak afternoon heating, augmented at times perhaps by weak disturbances drifting through aloft. Max POP may be centered on or around Memorial Day as a weak shortwave suppresses heights as it passes by to the north and some interaction takes place with `tropical` system migrating toward the southeast U.S. coast. Latest NHC forecast says this area of disturbed weather has a 30% chance of cyclone formation in the next 48 hours. && .AVIATION /12Z THURSDAY THROUGH MONDAY/... High pressure over the region will result in widespread vfr conds and light winds this morning. Passage of an upper lvl disturbance, combined with an increasingly moist ssw flow, will produce sct shra/tsra during the aftn and early evening. Although vfr conds will predominate, a brief vis reduction is possible assoc with a passing shra/tsra. Sct evening shra/tsra should taper off, as disturbance passes east of the region this evening. Focus will then shift to the potential of patchy late night fog in spots that happen to receive rain this aftn/evening. A moist swrly flow ascending the mtns could also result in ifr cigs at KBFD late tonight, as latest mdl soundings and SREF prob data suggest. OUTLOOK... Fri...Early am low cigs possible. Isold pm tsra impacts possible. Sat-Mon...Isold pm tsra impacts possible. && .CTP WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Dangelo NEAR TERM...Dangelo SHORT TERM...Dangelo LONG TERM...Steinbugl AVIATION...Fitzgerald is the U.S. government's official web portal to all federal, state and local government web resources and services.