Scientific Forecaster Discussion
Area forecast discussion
National Weather Service State College PA
1038 am EDT Wednesday Oct 1 2014
a slow moving upper level low will track east of the commonwealth
today. A strong cold front will push into the commonwealth Friday
night and Saturday.
Near term /through tonight/...
Slowly filling upper low will slowly track east of the
commonwealth today...bringing ever so slowly improving conditions
throughout the afternoon. Any breaks in the clouds will most
likely fill back in with diurnal cumulus. Steeper lapse rates in vicinity of
departing upper trough may keep a few showers over the area. Temperatures
will be cooler than recent days with highs ranging from the upper
60s north to the lower 70s south.
Shortwave ridging aloft and surface ridging return tonight into
Thursday...with another round of late night and early morning
valley fog if we can partially or mostly clear-out. Mins tonight
will range from the low to middle 50s.
Short term /Thursday/...
after morning fog dissipates...a mostly sunny and pleasant autumn
day is in store for Thursday as heights continue to rise and surface
ridging persists from large eastern Canadian surface high extending
into eastern PA. Maxes will be slightly warmer than Wednesday...
and reach the lower to middle 70s throughout.
Long term /Thursday night through Tuesday/...
progressive upper low/compact trough axis forecast to be lifting NE
into New England at the start of the period will be replaced by
a short period of rising heights late in the week. A second...much
stronger and expansive upper trough axis extending southward from an upper
low anchored over northern Ontario is forecast to sweep across the
eastern U.S. Over the weekend.
Warmer weather makes a brief return Thursday...Friday and early Sat as
the upper ridge temporarily rebuilds....with most maxes and mins
at least several degrees above climatology normals. Maximum temperatures Sat will
be below normal.
The arrival of the second trough will support a strong cold front
with deeper connections to the Gomex and the Atlantic
Ocean...thus potential for more widespread and heavier
rainfall than with the first front. Passage of the front will
also bring noticeably cooler temperatures to the region starting Saturday afternoon
Several short waves dropping into the upper trough / expected
cyclonic flow over the region will keep the weather cool and
unsettled into early next week.
Aviation /15z Wednesday through Sunday/...
vlifr left at only unv...but IFR persists in low clouds at
bfd/aoo/ipt. The clouds should lift with the heating but ceilings may
not improve all that rapidly there. Just a stray shower is
possible as the upper low is still overhead and stability could
lower just enough. Not enough of a coverage expected to include in
most tafs. The diurnal cumulus which develops in The Holes of the
stratus this afternoon will dissipate this evening. Thus...there
is a fairly strong signal again for IFR reductions tonight and Thursday
morning. The light east/southeast wind does not Bode well for
clearing/dissipation of the fog and any morning stratus Thursday am.
Friday...mainly VFR. Isolated thunderstorms and rain poss west before sunset. Low level wind shear possible.
Friday PM...showers and thunderstorms likely associated with a strong cold
front. Low level wind shear likely.
Sat...am showers eastern areas. Breezy with improving conditions east of
the mountains isolated showers and MVFR ceilings over North/Western areas.
Sun...MVFR ceilings possible northwest...otherwise VFR.