Area Forecast Discussion
Issued by NWS State College, PA
Issued by NWS State College, PA
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846 FXUS61 KCTP 031409 AFDCTP Area Forecast Discussion National Weather Service State College PA 1009 AM EDT Wed Jul 3 2024 .SYNOPSIS... High pressure will push off of the Mid Atlantic coast today. A dying cold front will push in from the Great Lakes tonight, then stall out over the area late this week. Low pressure tracking north of Pennsylvania will drag a cold front through the state Saturday. && .NEAR TERM /THROUGH TONIGHT/... Midlevel ACCAS tells of the increasing deep layer moisture across central PA this morning as H5 ridge axis retreats eastward. 850mb temps on the rise, too and there will be a noticeable uptick in humidity by this afternoon as a southerly flow increases ahead of a weak cold front over the Great Lakes. Diurnal heating and surging low level moisture should result a fair amount of afternoon cumulus, especially over the western mountains. Temperatures will be a few degrees above normal over the W Mtns and near average elsewhere, translating to highs well into the 80s areawide. Moisture advection and low level convergence along an approaching low level jet could potentially support a shower or thunderstorms in northwest PA this evening. A cold front will move into the region overnight and weaken as it approaches. It will help focus the potential for showers and thunderstorms mainly north and west of the I-99/I-80 corridor through daybreak Thursday. Rainfall amounts should generally remain less than a quarter inch, but isolated amounts over 0.75 inches are possible. Clouds and increasing humidity will result in low temperatures in the mid 60s to lower 70s by Thursday morning. && .SHORT TERM /THURSDAY/... A mostly cloudy day is in store for the Fourth of July with a noticeable uptick in humidity. Dewpoint temperatures will soar into the 70s across much of the region. Morning showers and storms associated with the decaying cold front will gradually move southeast through the day and should remain scattered in coverage. The front will be located over southern PA by Thursday afternoon, which is where most of the shower activity should be concentrated for any 4th of July and/or fireworks festivities. Highs on Thursday afternoon will generally be in the 80s with a few spots potentially reaching 90 degrees in the southeast before convection arrives. The threat for severe weather and flash flooding remains relatively low and is maximized (Marginal risk) along and south of I-76. The realization of any downburst winds or flash flooding will likely be contingent on some breaks in the clouds to generate instability. Bulk shear near the front will be sufficient for organization, but CAPE may be lacking owing to persistent cloud cover. Regardless, the chance of showers and storms should be monitored for anyone who plans to take part in outdoor festivities to celebrate Independence Day. && .LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/... The front is progged to stall out in the vicinity of Southern PA Thursday night, then return north as a warm front Friday ahead of low pressure lifting across the Grt Lks. Falling heights and surging pwats ahead of an upstream shortwave and associated surface low lifting across the Grt Lks should bring a round of showers/tsra in the Friday PM to Saturday timeframe. Current guidance suggests the shortwave and bulk of the large scale forcing will pass north of PA, leading to unimpressive mean qpf in the ensemble plumes of 0.25 to 0.50 inches Fri PM to Saturday. The bulk of guidance now supports fair and seasonable conditions Sunday into at least early Monday, as surface ridging and drier air work in behind the cold front. Showers and storms return to the forecast for early next week as another wave of low pressure tracking to our north brings a cold front through the region. Temperatures in the long term forecast look above average, especially overnight lows Wednesday through Friday night, when EPS pwats are 150pct of normal. && .AVIATION /14Z WEDNESDAY THROUGH SUNDAY/... VFR conds will prevail today with southerly flow gusting 15-20 kts, highest in the north. A cold front will approach tonight and lay out W-E over the state on Thurs. The deep moisture Wed PM and Thurs will allow for sct- nmrs showers and TSRA. Included VCSH in BFD TAF starting 03/20Z and MVFR cigs/vsby in showers with thunder possible after 23Z. The first batch of showers is expected to fizzle as it moves southeast through tonight, with additional showers and storms developing in the humid environment on Thu, especially south of BFD. Outlook... Wed night...TSRA NW (IFR poss), dry SE with no impacts. Thu...AM low cigs and isold SHRA possible W Mtns. Sct PM TSRA impacts possible over all the airspace, but mainly S of I-80. Fri...sct TSRA, impacts possible, mainly PM, highest covg W. Sat...sct-nmrs TSRA areawide, highest SE in PM. Sun...AM fog poss. Otherwise, no sig wx. && .CLIMATE... June 2024 was the warmest June on record for Bradford with a mean temperature of 66.6F, breaking the old record of 65.8F set in 2021. June 2024 was the 3rd warmest June on record for Harrisburg with a mean temperature of 76.0F. && .CTP WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...DeVoir/Fitzgerald NEAR TERM...DeVoir/Fitzgerald/Banghoff SHORT TERM...Fitzgerald/Banghoff LONG TERM...Fitzgerald/Bauco AVIATION...Gartner/Colbert CLIMATE...Colbert