Area Forecast Discussion
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FXUS61 KPBZ 270036
Area Forecast Discussion
National Weather Service Pittsburgh PA
836 PM EDT Wed Oct 26 2016
Low pressure will bring rain to the region tonight and Thursday.
Dry and cool weather returns for Friday. Warmer but unsettled
weather is anticipated for the weekend.
.NEAR TERM /THROUGH THURSDAY/...
Pre-frontal precipitation of rain with a mixture of light sleet
has shifted to the northeast. Therefore, have updated late
evening PoPs based on radar and latest HRRR trends for the late
evening update. Previous discussion follows.
PoPs are forecast to progressively increase overnight as an
approaching low pressure system strengthens resulting from a
deepening upper trough shifting across the Great Lakes. On
Thursday, categorical PoPs are placed over the north where
sufficient lift and moisture are expected to reside. The frontal
passage is slated for Thursday afternoon and thereafter sweep
away the rain to the east. Lingering precipitation over the
higher terrain is then expected due to cool northwest flow.
Temperatures will be slightly above normal through the period.
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
Cold advection behind the departing low pressure will be brief,
but shower chances should continue through Thursday night. Some
snow may mix in as well, especially north of I-80 and in the high
terrain. High pressure will settle over the Ohio Valley for Friday
with lingering cloud cover to likely hold temperatures down a
little. With the progressive upper level pattern, another system
is expected to approach late on Saturday with chances for showers
increasing by the afternoon. Warm advection ahead of this system
should allow for temperatures 5-10 degrees above seasonal
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
The models are in relatively good agreement for the start of the
long term, with another shortwave expected to cross along a slow
moving boundary over the Ohio Valley on Sunday. After this time,
the models evolve the next low pressure system over the northern
Plain/Canadian border differently, so a blend of model guidance
was used. Overall, expect temperatures to remain at or just
slightly above seasonal averages through the period.
.AVIATION /01Z THURSDAY THROUGH MONDAY/...
-- Changed Discussion --Main concern overnight will be potential for LLWS as surface winds
have decoupled from stronger winds already being observed via
RAOB/VWP/MDCRS observations. LLWS potential will continue into
morning. The potential will lessen somewhat as surface winds
increase this morning.
CIGS/VIS will remain VFR the remainder of the evening with MVFR
conditions developing after midnight as low pressure approaches
from the west.
Areas north of Pittsburgh will likely see IFR by sunrise and
continue for much of the day until winds shift and drier air moves
in mid/late afternoon.
.OUTLOOK /WEDNESDAY THROUGH SUNDAY/...
VFR returns by Friday. More restrictions are possible this
weekend with another front.
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