Scientific Forecaster Discussion
Area forecast discussion
National Weather Service State College PA
1114 PM EDT Tuesday may 5 2015
a nearly stationary front will keep unsettled conditions in place
through middle week. High pressure will return for the end of the
week. This week will be much warmer than normal.
Near term /until 6 am Wednesday morning/...
10 PM update...
Radar shows a loosely organized area of mainly light showers from
my northern tier down to just north of Harrisburg. The general
movement of the activity is eastward with a few stronger cells
Short term high res models support the idea that the upstream
convection currently back through Northern Ohio and Indiana will
continue east before dropping across about the northern 2/3 or so of my
forecast area between about 06 and 12z.
It will be another unseasonably mild night with lows from the
upper 40s over the far north to middle and upper 50s over the
Short term /6 am Wednesday morning through 6 PM Wednesday/...
wavy boundary stalled over the state will keep scattered showers
somewhere in the County Warning Area during the period. Hiest chance of precipitation is
likely to be over western and northern mountains...closer to shortwave energy
emerging from the plains. Scattered rain showers are possible in the morning.
The daytime instability will likely allow more showers during the
afternoon. Not so sure on coverage at this point...but best chances will
be in the SW in close proximity to the boundary and up against the
more-moist west-northwest 800 mb flow.
Long term /Wednesday night through Tuesday/...
forcing along the boundary should weaken with showers decreasing
in covering over south-central PA Wednesday night into early Thursday...as
an upper level ridge builds over the eastern half of the nation.
The synoptic pattern will have a decidedly Summer-time look and
feel through the weekend with high confidence in above normal
temperatures through the weekend. The precipitation pattern favors isolated
to widely scattered diurnal convection Thu-sun. A frontal system
approaching from the Great Lakes and Midwest will support an
uptick in probability of precipitation by early next week. Highest ndfd probability of precipitation are Mon-Tue.
Confidence in temperatures drops off to average by this time with
models and ensembles somewhat at odds with respect to maintaining
a strong upper ridge vs. A cooler more confluent flow aloft.
Overall have not deviated significantly from previous forecast
package and favored more of a mixed blend for days 7 and 8.
Subtropical low near/along the southeast coast is expected to
stay far enough south and not impact the area with precipitation or
Aviation /03z Wednesday through Sunday/...
scattered to numerous showers will focus along a slow moving front
dropping southward into PA overnight. Most persistent MVFR conds
will extend from the northwest mountains through kbfd and eastward
to the middle susq River Valley. Southern airfields including
kjst...kaoo...kunv and kmdt will be rainfree most of the
overnight. A small area of locally heavy showers will exit klns by
0430z. MVFR conds will drop southward through the central and
south central mountains and Laurel Highlands by by early Wednesday with
areas of fog possible. Cut back on the fog at the aforementioned
southern PA sites where showers were more isolated Tuesday evening.
Wednesday will be similar to today with scattered showers/thunderstorms
but VFR much of the time.
Thursday...am low ceilings/fog poss...especially kjst.
Fri-Sat...isolated PM thunderstorms and rain impacts poss West Mountains
Sun...scattered to numerous showers/thunderstorm activity with cold frontal passage.
near term...la corte