Scientific Forecaster Discussion
Area forecast discussion
National Weather Service State College PA
528 PM EDT Tuesday Aug 30 2016
high pressure will keep it warmer than normal and mainly dry
into Wednesday. A cold front will move across the commonwealth
late Wednesday and early Thursday, followed by a refreshingly
cooler airmass with low humidity Thursday through Saturday.
Near term /until 6 am Wednesday morning/...
fair and seasonable weather tonight, as high pressure ridge
remains over the state. Warm air advection aloft ahead of approaching shortwave
is already spreading cirrus into northwest PA at 21z and models
indicate the northern counties will experience an increase in high
clouds overnight, while mclear skies indicated by mdls in the
south. The cloud cover and a light SW breeze should preclude much
fog formation tonight over the northern counties. However, some patchy
fog does appear possible arnd dawn across the southern counties.
Low will range from the mid 50s to mid 60s northwest to southeast.
Short term /6 am Wednesday morning through 6 PM Wednesday/...
backing flow aloft will develop later tonight and Wednesday as a
weak trough drops out of the eastern gr lakes/southern Canada.
This will help bring about an increase in deep moisture which in
turn will touch off isolated to scattered showers and
Highs Wednesday will be very near today's readings with a gradual
increase in the humidity.
Long term /Wednesday night through Tuesday/...
the extended period looks like it will feature a transition from a
persistent upper-level ridge over the eastern United States to a
weak upper-level trough by mid to late week. As a result, above-
normal temperatures through the Tuesday-Wednesday timeframe will
transition to near or a little below normal by the end of the period.
Medium range guidance agrees with a second-stronger cold front
pushing southeast across the area late Wednesday through Wed night, with a
renewed chance for showers and thunderstorms. Have upped pops to
high-end chance with afternoon fcst package.
This front will be followed by a cool-down for the end of next week
and into Saturday. Max temps should be mainly in the 70s Thursday
into the weekend over the northern and western higher terrain, with
low to mid 80s elsewhere as an upper trough amplifies from central
Quebec...to the mid Atlantic Piedmont. Temps begin to creep up again
late weekend into early next week.
Interesting developments with potential eventual track of td9
after it slips across Florida into the Atlantic. Wed night's
front/trough will have pushed into the Carolinas by then, guiding
td9 off the Carolina coast on a NE trajectory. But 12z model
guidance (both GFS and ecmwf) hint at a potential bit of a
temporary jog back toward the New England coast Sunday or Monday.
For now, potential impacts to central PA are very low.
Aviation /22z Tuesday through Sunday/...
widespread VFR will continue into the overnight before patchy fog
once again develops toward daybreak Wednesday. After the early
fog, Wednesday will see VFR conditions return for most of the day
before scattered mainly afternoon showers and thunderstorms bring
Thu-sun...no sig wx expected.
short term...la corte