Area Forecast Discussion
Issued by NWS State College, PA

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000 FXUS61 KCTP 081952 AFDCTP Area Forecast Discussion National Weather Service State College PA 252 PM EST Mon Mar 8 2021 .SYNOPSIS... It will be a very quiet weather pattern for the next few days. Massive high pressure will slide off the East Coast tonight and allow a warm, southwest air flow. Temperatures will warm steadily into at least Thursday. Much cooler weather will follow after some rain late this week. && .NEAR TERM /THROUGH TONIGHT/... Clouds have spread to the SE and have temporarily tempered the warm up, but maxes should still be attained as the clouds thin and warm advection kicks in. A little gustiness to the wind is possible over the west, and may get a little gustier in the Laurels overnight as a strong low level jet kicks in. However, the LLJ will be waning by sunrise in the west. The main change to the forecast was to up the sky cover over the N as model RH is rather high during and behind a weak wind shift/trough passing through. The little bit of wind, cloud and WAA overnight will work together to keep temps from falling more than 3-4 degs, with some places staying steady or rising a few degs thru the night. The best chance for radiative cooling will be the valleys of the east, but even there, cooling might only be 5-7F thru the night. && .SHORT TERM /TUESDAY/... The warm up will continue through the middle of this week, but we won`t realize too much of the potential warming on Tuesday. Mixing heights only in the 2-4kft range will only tap warm- enough air aloft to get us into the 50s for most places. The valleys of the SE will touch 60F, though, and any deeper mixing could allow for a stray reading in the m60s. The west wind may be a little stronger than Monday. && .LONG TERM /TUESDAY NIGHT THROUGH MONDAY/... The 08/12Z GEFS projects anomalously warm 850mb temps to continue rising through the week, before peaking on Thursday. Much of central PA will see high temps top 60 degrees Wed and Thurs, with the southern valleys possibly making a run at 70 degrees (!) on Thurs. A cold front approaching from the Upper Midwest will bring increasing clouds by Thursday, and introduce a chc of rain showers across the northwestern counties. This front will slowly slip southeastward across the area on Friday, accompanied by a continued chc of showers. The medium-range models are coming into better agreement with building high pressure over the Great Lakes pushing the front south of the region Friday night. Behind the front, cooler /more seasonable/ temperatures will return for Saturday. Both the 08/00z ECMWF and the 08/12z GFS show a quick-moving reinforcing shot of chillier air for Sunday, with moisture and the next chc of widespread precip returning early next week. && .AVIATION /19Z MONDAY THROUGH SATURDAY/... VFR will continue as the sfc high slide east only slowly. A patch of 4-6kft clouds sliding overhead now will continue to thin/break into the evening. However, additional clouds will move down from the NW tonight, and BFD will likely fall near IFR by morning. However, it should not be for more than a couple of hours. Warming and progressive flow aloft will work together to dissipate them and push them out of the area. The clouds could get MVFR at JST, but have kept them VFR for the night. Biggest issue will be LLWS overnight. A strong low level jet slides across, peaking in speed during the middle of the night. The speed shear could be 40-45KTs in <2kft in many places. By 12Z or 15Z at the latest, though, the LLJet max should be past us, and take with it the threat of LLWS. Outlook... Tue...Early AM LLWS possible. AM low cigs possible NW Mtns. Wed...Patchy AM fog possible eastern Pa. Thu...Reductions to MVFR likely, IFR poss in late day & overnight showers, mainly in the NW. Fri...AM low cigs/showers, esp NW. Sat...Isolated showers/MVFR cigs poss. && .FIRE WEATHER... Spring fire season is starting in parts of CPA with a few brush fires reported over the weekend. High pressure over most of the eastern US will slide to the east Tues and Wed. Afternoon RHs in the mid 20s will recover into the 70s, but lower to the 30s and 40s Tues afternoon. The dewpoints will be climbing slowly as the warmer/moist air comes in from the SW through the middle of the week. Much milder conditions will occur into the middle of the upcoming week along with increasing humidity. Relatively light wind will freshen to 10 to 15 mph with gusts into the 20 to 25 mph range from the south on Wednesday. && .CLIMATE... Daylight saving time (EST->EDT) begins on Sunday, March 14th. The first day of astronomical spring (vernal equinox 2021) will be at 5:37 A.M. EDT on Saturday, March 20th. && .CTP WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Dangelo NEAR TERM...Dangelo SHORT TERM...Dangelo LONG TERM...Evanego AVIATION...Dangelo FIRE WEATHER... CLIMATE...

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