Scientific Forecaster Discussion
fxus61 kctp 240546
Area forecast discussion
National Weather Service State College PA
146 am EDT Sat Jun 24 2017
the combination of an approaching frontal system and the
remnants of Tropical Storm Cindy will funnel a plume of deep
tropical moisture bringing a steady rain to southern
Pennsylvania tonight. Occasional lighter showers are expected
across the northwest half of the state through the first half of
tonight. The cold front will push east across the region during
the morning Saturday, followed by drier and cooler air with
comfortable humidity that will last through much of next week.
Near term /until 6 am this morning/...
large area of stratiform rain covers much of central PA...with a
broken heavier line of showers with perhaps isolated thunder
tracking across the lower susq River Valley early this morning.
Hourly rates are not that impressive over the Laurel Highlands,
but will watch rises from earlier rains which caused a good
spike at confluence.
Flash Flood Watch remains in effect overnight for the Laurel
Highlands. Heaviest rainfall will track east of the region by
12z as sfc cold front whisks deep layer moisture to the east
Short term /6 am this morning through 6 PM Sunday/...
conditions will improve rapidly Saturday morning as the deep
moisture speeds eastward. NHC expects whatever is left of Cindy
to be on the Maryland coast by 8am so the best of the rain will be
over with drier air sweeping in behind the departing low and
Long term /Sunday night through Friday/...
models have trended toward much better agreement with the
evolution of the seasonably strong large scale upper trough over
the eastern U.S. A couple of shortwave impulses reflecting weak
surface fronts or troughs will provide a limited/mainly diurnal
opportunity for widely scattered showers/isolated low- topped
thunderstorms Sunday-Tuesday. However, much of the this period
will be pleasant and dry with below normal precipitable water supporting low
humidity and below normal temperatures relative to late June
The trough is fcst to lift out and leave a more zonal pattern by
the middle of the week, followed by a resurgence of the
southeast U.S. Upper ridge. Models and ensembles show the ridge
breaking down in the west as a trough shifts east across The
Rockies into the plains. Southerly flow increasing ahead of its
attendant frontal system should result in an upward/warmer trend
in temperatures accompanied by low level moisture/humidity.
Expect Max/min temps to get back to seasonal levels around
midweek and likely reaching above normal levels by next Friday.
Aviation /06z Saturday through Wednesday/...
moisture associated with the remnants of ts Cindy now moving
rapidly eastward across Pennsylvania. Last band of heavier rain
and embedded convection now across the central southern tier
counties extending into the lower Susquehanna region.
Radar also depicting scattered shower activity along the cold
front which is just about into kbfd at 06z.
Rain and front will rapidly slide east across central Pennsylvania
between 06z and 10z. While moist upslope flow will keep lower
ceilings in western mountains a bit past 12z, most areas across
the central and southern areas will rapidly improve to VFR with
the frontal passage.
Saturday will feature mainly VFR conditions after any lingering
lower ceilings in the west lift by mid morning. A brisk west-
northwest wind of 10 to 20 knots can also be expected behind the
system during the late morning and afternoon.
Sat...scattered restrictions in am showers...otherwise becoming
Mon-Tue...mainly VFR, but with a chance of shra/tsra.
kccx radar will be offline for approximately 4 days starting
Saturday, June 24th for technicians to install the first of 4
major service-life extension upgrades. The work on the radar has
been scheduled to minimize potential impacts to operations and
will be delayed if hazardous weather is forecast.
Flash Flood Watch until 5 am EDT early this morning for paz024-
near term...devoir/la corte