Scientific Forecaster Discussion
fxus61 kctp 181154
Area forecast discussion
National Weather Service State College PA
754 am EDT Wed Oct 18 2017
above average warmth and dry weather will continue through the
weekend, adding to one of the warmest starts to October on
record. The dry spell will end early next week, followed by a
cooler weather pattern leading up to Halloween.
Near term /through tonight/...
big bubble no trouble. Sunny day a good 5f warmer than yesterday
with lighter winds.
Another clear comfortable autumn night.
Short term /Thursday through Friday night/...
a bit warmer still on Thursday. A wave weakens the high a bit
and the gradient is a bit stronger so could be a bit more windy.
But the high builds back in as the wave, well up in Canada
passes by. It does drag some slightly cooler air in Thursday
afternoon into early Friday.
But warm air with above normal 850 hpa temperatures is poised to
move in behind the rebuilding high Friday for a warm late-day
Friday and probably a warmer still Saturday.
Enjoy the fine weather is the key here.
Long term /Saturday through Tuesday/...
a strong upper level ridge of high pressure will support above
average temperatures through the weekend. This will further add
to the anomalous October warmth which should help to secure a
spot in the top-10 warmest octobers - if not top 5 or even #1.
Both GFS and European model (ecmwf) ensemble systems continue to indicate a
pattern flip by the middle of next week with a period of colder
(near/below normal) temperatures starting around October 25th.
The depth and longevity of the emerging upper trough and
subsequent cooler pattern remains in question - so we will have
to wait and see how much of a Dent it can put in the strongly
positive month-to-date departures from climatology.
On the precipitation side, the prolonged dry spell ends early
next week as a cold front moves across the Appalachians. Stream
separation differences/closed low development in some of the
deterministic models leads to increasing spread and thus
uncertainty in the forecast details such as timing. The gom will
be open for moisture inflow northward ahead of the front. So
will keep continuity and favor Max pops in the Monday night-
early Tuesday timeframe.
Aviation /12z Wednesday through Sunday/...
clear skies will prevail through the next 24 hours, and likely
beyond that. Winds through the period will generally be light
as well, favoring the southwest under 10 knots.
Generally no restrictions expected through Sunday, except for
some patchy valley fog in the overnights and near sunrise. This
should become more prevalent later in the period, Friday through
Wed-Thu...no sig wx expected.
Fri-sun...mainly VFR, with just some patchy am valley fog.
month-to-date, October 2017 is the warmest October on record at
Harrisburg and Williamsport.