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409
FXUS61 KPBZ 181603
AFDPBZ

Area Forecast Discussion
National Weather Service Pittsburgh PA
1203 PM EDT Wed Apr 18 2018

.SYNOPSIS...
Precipitation chances return today and Thursday with crossing
low pressure. Dry weather will return this weekend with
seasonable warmth next week.

&&

.NEAR TERM /THROUGH TONIGHT/...

Ridging/return to southwesterly sfc flow ahead of approaching
low pressure and increased insolation will support warmer
temperature today. From a climatological stance, we are still 5
to 10 degrees below average for temperatures.

Showers will spread across the Upper Ohio Region this evening
as the aforementioned low approaches. Cold advection will ensue
as the system passes with rain showers changing to snow
overnight.

&&

.SHORT TERM /THURSDAY THROUGH FRIDAY/...

Precipitation will continue Thursday and may mix with/change to
rain over areas south of Pittsburgh as the boundary layer warms
through the day. Otherwise, the cold thermal trough with a deep
trailing shortwave should maintain showers of snow despite
surface temperatures above freezing. Confidence is sufficient in
this scenario to go above most guidance and project categorical
POPs. No significant accumulation is expected given relative
boundary layer warmth and sun angle.

Friday and Saturday will be cool days of improvement as surface
high pressure builds under cold northwest flow. Expect highs for
those days 10 to 15 degrees under the averages respectively.

&&

.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
Split flow is projected over the CONUS next week with nrn stream
ridging, and a srn stream low forecast to support dry conditions
with a warming trend for the Upper Ohio. The next chance for
precipitation looks to be with the advance of a mid week nrn
stream trough, which model-world may be phasing too quickly with
the exiting srn low. Shortwave ridging between srn stream lows
would retard a moisture tap off the Gulf, so only a slight rain
chance was included for the immediate area. The bottom line is
that indications of a dry period with seasonable warmth are
good, and may be interrupted only late in the period.

&&

.AVIATION /16Z WEDNESDAY THROUGH SUNDAY/...
Ceilings will continue to lift as day time mixing takes over.
VFR conditions for the majority of the sites are expected until
this evening...with the exception of DUJ/FKL. Low level moisture
still lingers for these northern sites and ceilings will max
out near 3,000ft. Winds will be fairly light, and at times
variable, for ZZV/HLG/MGW as high pressure is centered over
eastern Ohio. MVFR and IFR conditions are expected to return to
all sites near 03Z as quick short wave brings rain and then
snow showers to the region.

OUTLOOK... Expect a stretch of VFR conditions after Friday
morning and into the weekend.

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...None.
OH...None.
PA...None.
WV...None.

&&

$$