Scientific Forecaster Discussion
Area forecast discussion
National Weather Service State College PA
1121 PM EDT Friday Oct 24 2014
a ridge of high pressure will drift across the area tonight. A
weak cold front will race southeast across the state Saturday
followed by a string of dry and increasingly mild days for Sunday
into Tuesday. Another cold front should impact the area by middle
Near term /until 6 am Saturday morning/...
a weak upper shortwave continues to push some scattered-broken high clouds
over the area this evening...mainly the eastern half.
High pressure will drift overhead tonight and help slacken the
wind as the blyr decouples under clear-scattered skies. Lows
tonight will vary from the middle 30s across the mountains NE of kipt...to
the u30s and lower 40s elsewhere.
Short term /6 am Saturday morning through 6 PM Saturday/...
Saturday looks like an excellent fall day for outdoor activities
/and leave raking early in the day/. However...a tightening
p-gradient across the region will kick up a gusty westerly wind by
late morning and the wind will gust between the upper teens and
middle 20 knots range throughout the afternoon and early evening hours
ahead of an approaching cfront.
Temperatures will be rising to between 55f /NW mountains/ and the middle to upper
60s /se/ as 800 mb temperatures will be holding between 5c and almost 10c in
The weak...and mainly dry cold front will enter the northwest before
dark and should be through the whole area before midnight. A few
light showers will fall across the northern mountains...but most or all
these should dry up as they descend the Allegheny Front just northwest
of kaoo...kunv and kipt with just a few sprinkles at those central
Northwest winds should pick again and become gusty at...and just after
the frontal passage with well-aligned wind profile and up to 50kt
winds as close as 5kft above ground level. Will mention gusts into the 20s but
decoupling around the time of passage my keep the strongest of the
winds from getting down to the surface. The wind Sat night will keep
it from getting too cold with mins expected to be in the 40s for
the most part.
Long term /Saturday night through Friday/...
an active split flow jet stream pattern over the conterminous
U.S. Will dominate the long term period. General troffiness over
the northestern U.S. Early in the period will be enhanced by several
shortwaves before heights build over the eastern third of the
country into the middle of next week. By the end of the
period...troffing/falling heights are forecast to return to the
At the surface...high pressure over Dixie will slide east toward
Bermuda and lead to a warm srly flow. A trough and associated cold
front will cross the northern plains and upper Great Lakes Monday and
Tuesday. High temperatures in PA on Tuesday may get into the u60s north and
u70s in the south...or about 15f to 18f above normals. The main
surface low with this long- wave trough will slide from ls to James
Bay late Tuesday into Wednesday. The cold front extending to the south off
the low will whip through - perhaps fairly dry - late Tuesday and
Tuesday night. It should then hang up over the Middle- Atlantic States.
Will therefore draw the Bell curve of probability of precipitation to surround Tuesday
night...but also linger some slight chances in the southern tier for Wednesday.
The confidence lowers some for the second half of next week. It
does appear that another northern stream system zips in from the west
later in the week...and may have the coldest air of the season
behind it if the ec is your preferential model du jour. Other
solutions are not quite so profound with the sharpness of the trough
and coldness of the airmass behind it. In any case...the trough
and colder air appears to move out very quickly in the progressive
Aviation /03z Saturday through Wednesday/...
MVFR ceilings overspreading northwest PA from Lake Erie through 05z
and should persist for much of the overnight. VFR ceilings expected
to prevail at all other airfields overnight through much of
Sat-Tue...no sig weather expected. Brief MVFR ceilings and visibilities possible
in scattered late day night time showers across northern Penn in vicinity of kbfd and
north of kipt.
Tuesday night and Wednesday...areas of MVFR possible in scattered showers as a
weak cold front slides southeast across the state.
near term...la corte