Area Forecast Discussion
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FXUS61 KCTP 231843
Area Forecast Discussion
National Weather Service State College PA
243 PM EDT Thu Mar 23 2017
High pressure will drift off of the eastern seaboard tonight,
allowing a warm front to lift into the region Friday. Patchy
sleet and freezing rain is expected over central and northern
areas from the early to late morning Friday before precipitation
changes to all rain. The rain front will stall along the New
York border, then oscillate in the vicinity of northern
Pennsylvania through early next week...separating milder air to
the south from cooler air and showers north.
.NEAR TERM /THROUGH TONIGHT/...
Much milder conditions being enjoyed late this afternoon thanks
to return southerly flow west of the offshore sfc ridge.
Scattered cirrus is slightly dimming sunshine in spots but
overall a much more pleasant day than Wednesday across central
The first half of tonight will be clear and calm with
temperatures falling off through the 30s to near or below
freezing across much of central and north central areas. Warm
front advances overnight and model consensus brings a period of
precipitation across the commonwealth after 06z...a mixture of
IP and ZR for many areas...which has prompted Winter Weather
Advisory issuance for the northern two thirds of central PA east
of the Alleghenies. Far southern tier may see patchy freezing
rain...but confidence too low at this time for WSW issuance as
per collaboration with LWX, PHI.
.SHORT TERM /FRIDAY/...
Model consensus keeps threat of fzra between 09Z-15Z
Friday...before changing to plain rain central and northeast.
Expect less than one tenth of an inch of ice as QPF is light,
but untreated roads will become slippery for morning rush.
WAA lifts north of the region with 850mb baroclinic zone by
midday Friday, indicating a dry and warmer afternoon across the
area. Models indicate surface warm front will work into the
central counties late in the day, pushing temps well into the
50s, while areas east of IPT and LNS will likely remain in the
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
The models and ensembles continue to show a series of upper
troughs progressing onshore from the Eastern Pacific and across
the Southwest/South-Central Plains before deamplifying as they
move east of the MS River. The first of 3 upper troughs emerges
from the Southern Plains and crosses into the MS Valley Sunday
and continues to weaken as surface frontal wave translates
downstream crossing the OH Valley/Great Lakes into the northern
Mid Atlantic states by Monday. Blend of NBM/ECENS/WPC still
indicating max POPs in the Sunday-Sunday timeframe.
Above average temperatures are expected over the weekend with
the warmest day likely on Saturday with some sites approaching
70F over southern PA. Sunday should be markedly cooler behind
a backdoor cold front and a likelihood of rain. However, above
average temperatures (especially nighttime) appear very likely
through early next week, as 00Z GEFS indicates Pa remains
beneath a mean upper level ridge and plume of anomalous PWATs.
The chance of showers will spike with passage of next shortwave
.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
Widespread VFR flying through the period. High to mid level
clouds will increase tonight with surface winds veering to
90-160 degrees. Light precip will likely move across the
airspace between 06-18z Friday, starting as RA/FZRA/PL before
transitioning to all RA by 15z Friday. Added PROB30 group to
hedge toward brief period of ice mix around daybreak Friday.
Fri...VFR/MVFR. Pcpn ending after 18z.
Sat...Mainly VFR. Chance of rain northern 1/2 airspace.
Sun-Tue...Sub-VFR with periods of rain.
Minimum temperature records for 3/23 at select sites:
MDT: 14 in 1934
IPT: 8 in 1906
BFD: 5 in 1959
AOO: 15 in 1960
Winter Weather Advisory from 4 AM to 11 AM EDT Friday for