.AVIATION /01Z WEDNESDAY THROUGH SUNDAY/...
Widespread VFR conditions prevail as of 01Z Wednesday, with
these conditions likely (80-90% confidence) to continue at all
airfields outside of BFD through ~12Z Wednesday. In this
timeframe, approaching a line of SHRA with embedded TSRA will
approach NW PA closer to the ~03/04Z timeframe. This will likely
bring low-end VFR to high-end MVFR ceilings which will persist
throughout the entire overnight period and throughout much of
the evening hours on Wednesday (~22/23Z Wednesday). Closer to
the 12Z timeframe, increasing signals for IFR at BFD based on a
consensus of HREF ensemble members and multiple cycles of GLAMP
model guidance, so have decided to include these in the TAFs
with moderate (~40-50%) confidence on timing. A brief period of
lower ceilings trending towards LIFR will be possible; however,
confidence remains too low for inclusion in the 00Z TAFs.
Elsewhere, the aforementioned line of SHRA/TSRA is expected to
diminish in intensity/coverage overnight, leading many airfields
unlikely to receive any SHRA in the 00Z-12Z Wednesday
timeframe. Recent HREF runs have been fairly consistent with the
progression of a low-level cloud deck across all of central
Pennsylvania, so have included these mentions and slightly
adjusted timing based on recent HREF/NBM/GLAMP model guidance in
order to outline initial onset of MVFR restrictions. There is
high (~70-80%) confidence on SHRA/TSRA reforming during the late
morning to early afternoon hours (mainly after 16Z) with
increasing coverage into the evening hours. Current SHRA
mentions have been included at all terminals across central
Pennsylvania based on recent forecast/HREF/GLAMP model guidance
with most uncertainty with respect to timing. In terms of TSRA
coverage, the highest potential at this time is outlined across
SE PA (MDT/LNS) where enough instability will be present in
order for some mentions in the TAF. At this time, have trended
towards PROB30s; however, if the cold frontal passage trends
quicker than forecast, could see mentions removed at MDT/LNS in
future TAF packages.
Outlook...
Thu...Lingering showers across S PA, restrictions possible.
Fri...Restrictions likely with rain moving in from south to
north, lasting into Fri night.
Sat-Sun...Restrictions likely with rain.
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