Area Forecast Discussion Issued by NWS State College, PA
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000
FXUS61 KCTP 290547
AFDCTP
Area Forecast Discussion
National Weather Service State College PA
147 AM EDT Fri Mar 29 2024
.SYNOPSIS...
High pressure will briefly build into Pennsylvania tonight and
Friday allowing for some gusty winds and dry conditions, then a
weak area of low pressure approaching from the midwest will
pass across the state Saturday bringing scattered rain across
the state. A more significant low is likely to track just north
of Pennsylvania through the Eastern Great Lakes early next
week.
&&
.NEAR TERM /UNTIL 7 AM THIS MORNING/...
The weak area of low pressure continues to move off the east
coast of the Mid-Atlantic and New England. Light drizzle will
continue for the extreme south east areas of Pennsylvania before
tapering off this evening. Warm advection aloft will continue
to support a veil of high clouds over these areas even after the
rain has ended.
Fair and seasonable weather is anticipated tonight, as the
upper trough shifts east of the state. However, a weak area of
low pressure diving across the Ohio Valley could potentially
come close enough to produce a few snow showers over Southern
Somerset County, roughly a 25% chance. If snow does occur it
would be brief in nature and result in a dusting at most.
&&
.SHORT TERM /7 AM THIS MORNING THROUGH SATURDAY NIGHT/...
Thinking for Friday remains unchanged with large scale
subsidence behind the exiting trough resulting in sunny,
breezy and seasonable weather Friday. Mixing down model 850mb
temps of around -1C to -4C translates to expected highs ranging
from the mid 40s over the N Mtns, to the mid and upper 50s
across the Lower Susq Valley. Bufkit soundings also support
wgusts several knots above NBM guidance Friday afternoon and
dewpoints a few degrees below due to fairly deep mixing. Higher
fuel moistures should limit the risk of wildfire spread, despite
expected wind gusts near 30kt and RH falling to around 30pct,
although some parts of far southern PA could fall into the 20s.
An active pattern is likely for the start of April. The first
system will bring showers to much of central PA on Saturday with
a quick tenth to quarter inch of rain possible during the day on
Saturday. Showers linger into Saturday evening before tapering
off. A mild and dry day is expected to round out the weekend on
Sunday with ridging nosing in from the south east Saturday
night.
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.LONG TERM /SUNDAY THROUGH THURSDAY/...
Sunday looks dry to start as a west-to-east oriented boundary
sags south of the Mason-Dixon Line. A wave of low pressure along
that boundary will lift back into Pennsylvania early next week,
bringing widespread rainfall Sunday night through Tuesday.
Zonal flow aloft often promotes seasonable temperatures, but
rain and clouds will likely result in temperatures trending a
bit below average for the start of April with highs in the upper
40s to low 50s.
For the second half of the week, ensemble guidance depicts a
deepening low pressure system moving into the northeast and
bombing out off the New England coast. This system is likely to
bring ample precipitation and strong winds. Current temperature
profiles indicate some snow potential at higher elevations in
the northern mountains and Laurels, but details remain highly
uncertain.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
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High (> 90%) confidence in VFR conds prevailing across central
PA through 06Z Saturday with widespread SKC/SCT high-level
clouds for a majority of the forecast area. A SCT low-cloud deck
near 5000ft AGL will clip portions of far south-central PA,
with HMZ/JST being on the northward extent so have outlined
these in the 06Z TAF package, but generally expect the SCT
coverage to prevail through 13-14Z Friday.
The main concern in the next 24 hours aviation-wise will be
with respect to gusty winds (sustained 15-20 kts with gusts up
to 30 kts) at 290-330 after sunrise on Friday and continuing
through the evening hours. There is also some concern for LLWS
criteria being met in the 03-06Z Saturday timeframe at airfields
along the southern ridges with a localized enhancement of the
LLJ. The 06Z TAF package outlines this potential for AOO/JST
which outline higher (40-50%) confidence for these thresholds
being met, while keeping mentions out of UNV and eastward due
to lower (< 20%) confidence at this time.
Outlook...
Sat...Rain moves in from W early AM, restrictions possible.
Sun...Lingering rain across mainly SW PA early, rain moves in
and becomes areawide later in the day.
Mon-Tue...Widespread rain continues with some potential for TSRA
Tuesday afternoon into the evening.-- End Changed Discussion --
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.CTP WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SYNOPSIS...Fitzgerald/Bowen
NEAR TERM...DeVoir/Bowen
SHORT TERM...Fitzgerald/Bowen
LONG TERM...Banghoff
AVIATION...NPB