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-- Discussion containing changed information from previous version are highlighted. --
715
FXUS61 KCTP 240915
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
515 AM EDT Sun Sep 24 2017

.SYNOPSIS...
A ridge of high pressure at the surface and aloft will keep the
region dry through mid week. A trough of low pressure will
bring cooler, more seasonable weather to end the upcoming week.

&&

.NEAR TERM /THROUGH TONIGHT/...
Nighttime blended images show the tendrils of valley fog
growing over the Northern and South-Central Mountains. It`s all
pretty much a carbon copy of the last several nights where we
will start off the day with the areas of fog, ending up with
plentiful sunshine and some late season summer-like warmth.

There will be a noticeable increase in humidity today with
dewpoints creeping into the mid 60s, resulting in more
uncomfortable conditions than we have seen recently.

Highs will be quite warm with some highs nudging 90 in some
locations over the Susq Valley.

It will remain mild overnight tonight with dewpoints making it
feel a little humid.

&&

.SHORT TERM /MONDAY/...
Monday will see more of the same, some fog early, followed by a
sunny and unseasonably warm afternoon.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
The blocking high that has been responsible for the recent
extended spell of dry and anomalously warm conditions is
forecast to start breaking down by the middle of the upcoming
week when shortwave energy sliding along the US-Canadian border
finally chews away at the high heights and brings some cooler
air eastward.

In the meantime the future of Maria is still not quite set in
stone. The latest ECENS has shifted a bit to the right, but the
GFS/GEFS/NAEFS and Canadian Ensemble all bring the center of
Maria perilously close to Cape Hatteras by late Wednesday. With
the strength of the ridge north and east of the hurricane, it
seems plausible that it will continue on a NNW track at least
closely threatening the coastal waters, before the northern
stream shortwave finally paves a path for a hard turn east
before the storm hits 40 deg north.

As it stands now, it looks like the first chance we will have
to see any rain might be Wednesday with a weakening cold front
that is destined to fall apart in the unfavorable shear on the
north side of the sprawling hurricane slated to be off the Mid
Atlantic coast by that time.

There are still differences in how much of a trough carves out
over the NERN US for the end of the week into next weekend. The
00Z ECMWF seems to be an outlier closing off a potent upper low
over the Gr Lakes before dropping it into Pa by Sunday. The
other ensemble suites show troughing, but no closed circulation.
I leaned toward the blended MOS for generally low POPs starting
Friday associated with the weak troughing that consensus is
leaning toward.

The surest bet will be that the week will end on a
significantly cooler note than it starts.

&&

.AVIATION /09Z SUNDAY THROUGH THURSDAY/...
-- Changed Discussion --
As of 5 AM, fog gone at BFD.

No big changes to 09Z TAFS.

Earlier discussion below.

Looking at mainly VFR conditions today. Some fog at BFD, but
variation in obs would indicate that fog is more like ground
fog.

Mainly VFR conditions will continue well into mid week. Patchy
valley fog will be possible for a couple hours near sunrise each
morning, mainly over the northern mountains.

.Outlook...

Mon-Thu...Patchy AM valley fog possible. Otherwise VFR
conditions.
-- End Changed Discussion --

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$
SYNOPSIS...La Corte
NEAR TERM...La Corte
SHORT TERM...La Corte
LONG TERM...La Corte
AVIATION...Martin