Area Forecast Discussion
Issued by NWS State College, PA

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FXUS61 KCTP 261040

Area Forecast Discussion
National Weather Service State College PA
640 AM EDT TUE JUL 26 2016

A weak front will remain south of the commonwealth through
Wednesday. High pressure will return for mid week with continued
warm temperatures. An area of low pressure approaching from the
west is likely to lift through the region on Friday.


Diffuse sfc cold front south of the Mason Dixon line early this
morning. Air mass remains warm and quite humid to the north of
it...and areas of fog are widespread. A few METARs have dropped
below one mile and the worst visibility appears to stretch from
York to Lancaster and Lebanon Counties as of 645 AM. The fog
should dissipate by mid morning as drier northerly boundary layer
flow helps break it up.

Deep layer moisture continues to decrease from north to south
thanks to flat ridging building eastward from the Ohio Valley and
northerly component to boundary layer flow in the wake of
aforementioned front. This will keep the focus for diurnal
convection south of the region over MD/WV/VA this afternoon and
evening...although an isolated shower or tstorm cannot be entirely
ruled out across southern portions of the Laurel Highlands.

Despite slightly lower dewpoints over central PA will
still be quite warm and humid with highs ranging from the lower
80s north to the lower 90s south...where Apparent temps will
reach the upper 90s.


Rich deep layer moisture remains pooled south of the Mason Dixon
line tonight and Wednesday...providing dry conditions overall.
Mid to high level convective debris from the midwest and Ohio
Valley may filter the sky from time to time particularly on
Wednesday...and there is a better chance of an afternoon or
evening thunderstorm Wed aftn along the Maryland border over
southern portions of the Laurel Highlands and south Central
Mountains. Elsewhere it should remain dry and very warm.

Lows tonight should reach the comfortable mid to upper 50s
northwest...ranging to the muggy lower 70s southeast. highs
Wednesday will be a few ticks higher than Tuesday across the north
and generally unchanged south...and will range from the mid 80s
north to the lower 90s southeast.


In the extended the heat continues through midweek...then a
cooling trend to near normal highs looks likely for a few days as
several fronts linger over the area and the core of hot
temperatures shifts west.

The upper ridge across the Southern U.S. is forecast to
retrogress into the Southwestern U.S. by late in the week allowing
northern stream energy to produce a weak, but persistent troffing
across the northeast states.

Cold front currently crossing the region is forecast to stall just
south of the PA/MD border. A wave is forecast to form on the front
supported by the developing upper trof, moving east through the
Ohio Valley Friday and crossing PA on Saturday into Sunday. This
looks to bring a prolonged period of unsettled with weather with
showery conds across the state. The cloudiness will further
support cooler high temperatures than recent days. Low
temperatures during this period look to be several degrees above
normal, especially across southern sections of the state.


No wind around the area so the weak front will stick just S of
the border tonight and perhaps into Thursday. Fog is once again
the main concern for the next 6 hrs. IPT has been down and up with
the vis recently, but the low cig at fl003 will probably hang on
all night with LIFR expected no matter the vis. Other terminals
may also get foggy or low cigs. However, climatology is
unfavorable for IFR to develop anywhere but JST and BFD. It has
had a chance to dry out at BFD. So, maybe only JST will sink as
low as IPT. Have included MVFR fog at all other terminals. Once
the fog/crud lifts, it should be dry with lower humidity levels,
and mainly VFR conditions. There is the smallest chance for a
late-day SHRA at JST, but have not included a mantion at this





Neither Harrisburg nor Williamsport reached/exceeded their record
max on Monday (7/25).




SYNOPSIS...DeVoir/La Corte
SHORT TERM...DeVoir/La Corte
LONG TERM...Lambert/Gartner
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