Scientific Forecaster Discussion
fxus61 kctp 280302
Area forecast discussion
National Weather Service State College PA
1102 PM EDT Tue Jun 27 2017
high pressure build into the area tonight providing dry and cool
conditions. Wednesday morning will be quite chilly with lows in
the 40s and 50s. The high will move off the East Coast setting
up a warmer and more humid airflow beginning on Thursday. A cold
front on Saturday will bring a brief break in the humidity.
Near term /until 6 am Wednesday morning/...
isolated showers winding down over the Endless Mountains. Will
Cary slight chc pops through midnight. Drier air to the west
has brought an end to all other activity. With clear skies and
light winds, look for good radiational cooling for a few hours
overnight and by morning temperatures will be in the 40s over
the northern half of the area and 50s elsewhere.
Short term /6 am Wednesday morning through Wednesday night/...
high pressure provides a quiet weather day with mild afternoon
temperatures with low humidities for the afternoon hours, making
for very comfortable weather for late June.
Long term /Thursday through Tuesday/...
did not make a lot of large changes on this package.
Warm advection on Thursday could result in an isolated
strong storm, mainly along the New York border. Fcst dewpoints
not all that high for late June, so think activity will
Overall the pattern is becoming more humid, more like
one often gets in late June into late August. The main
thing is that while 500 mb height rise into next week,
the combination of a weakness across the eastern part
of the country at 500 mb, wet ground, and higher dewpoints,
will result in some showers and storms at times next week.
Prior to this, a weak cold front will move into the area
by the weekend. Most likely this weak cold front will move
across the area on Saturday but the front is progged to be
weak, so temperatures will not change much, just a bit of a
break in the humidity.
Did go with a dry period Sunday night into early Tue.
Went with some showers and storms after this, but did
adjust superblend probability of precipitation some to fit with the pattern and
Aviation /03z Wednesday through Sunday/...
high pressure building into the area from the Ohio Valley will
supply mainly VFR conditions and light wind tonight across
central PA. Only area of concern is bfd, and to a lesser degree
ipt. Both locations received rain showers late this afternoon,
making those spots more susceptible to fog overnight. For now,
am banking on just enough of a breeze to preclude significant
vis reductions at bfd and would put the odds of IFR conditions
there at about 25 pct. At ipt, the rain was lighter and would
put the odds of significant (ifr) reductions there at around 10
pct. Elsewhere, confidence is very high in VFR conditions
Any patchy fog that may form overnight should burn off by around
13z Wednesday. High pressure over the region should ensure VFR
conditions and light winds for the rest of the day.
Thu-Fri...isolated PM tsra impacts poss, mainly northern PA.
Sat...scattered PM tsra impacts possible.
Sun...no sig wx expected.