Scientific Forecaster Discussion
fxus61 kctp 250628
Area forecast discussion
National Weather Service State College PA
128 am EST Sat Nov 25 2017
a cold front will move into northwest PA by morning and sweep
southeast across the state Saturday with just scattered brief
light rain showers as it passes. This will be followed by colder
air, with scattered light snow showers over parts of the
northwest mountains and Laurel Highlands Saturday night into
Sunday. A prolonged period of mainly dry and seasonably mild
weather is then in store for much of next week.
Near term /until 8 am this morning/...
look for increase in mid-high cloud cover for remainder of night
with temperatures milder than recent nights.
Short term /8 am this morning through 6 PM Sunday/...
light rain showers will be nearing the northwest mountains by 12z Sat,
with best rain chances during the day. Front is fairly weak and
not overly impressive, so only place I could muster likely pops
was in the northwest mtns, and even there just looking at 0.10" or less
of quantitative precipitation forecast. Showers more scattered in the central mountains, and may
only see a sprinkle or even no rain at all in eastern sections
as front weakens even further as it progresses eastward. Temps
will be about 5f above normal over the east in the warm air advection ahead of
Long term /Sunday night through Friday/...
the pattern that has been in place will prevail into late
Fast flow will bring small fast moving systems from the west
with some cold air from time to time, followed by warm periods
between cold periods. The tendency to have a ridge over the Gulf
will limit moisture. Thus a few showers with the cold fronts and
limited snow showers in the cold air will be about it.
00z models did support some snow showers across the far north
Sunday night and early Monday, but wpc charts and 12z guidance
show fronts too far to the north. An example of this is that
there is no cloud cover this afternoon, until one gets into
Thus I did back off snow showers across the north late Sunday
and early Monday.
Near record to record high temperatures fcst into the plains
early next week, this airmass heads toward our area, with plus
20 degree air at 850 mb to the west.
This will give US a mainly mild and dry week.
Some models last night showed a deep upper lvl low forming off
the southeast coast late next week, but models have a large
spread. I did back off superblend winds some for next Friday
Aviation /07z Saturday through Wednesday/...
high pressure in control into tonight with widespread VFR
conditions and minimal clouds. A moderately strong low-level
jet will move over the northwest half of the state tonight creating a
layer of low level wind shear based around 2 kft above ground level as speeds increase to
around 35-45kts. Surface winds over that area will become light
this evening, but pick back up to around 10 kts overnight,
higher on the ridgetops.
A weak cold front will bring scattered rain showers to mainly
western sections on Saturday, with MVFR restrictions becoming
likely by late morning over the northwest mountains, and IFR
restrictions possible between 18z to 00z. This front will spread
to much of the northwest half of County Warning Area in the afternoon and early
Sat...chance of rain showers mainly over northwest half, changing to
snow showers Sat night. Cig restrictions likely northwest half.
Sun...chance of snow showers across the northwest in the morning.
Otherwise no sig wx expected.
Mon-Wed...no sig wx.