Area Forecast Discussion
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517
FXUS61 KPBZ 230209
AFDPBZ

Area Forecast Discussion
National Weather Service Pittsburgh PA
909 PM EST Wed Nov 22 2017

.SYNOPSIS...
Dry weather can then be expected until the approach of the next
front on Saturday.

&&

.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
Low-level flow is beginning to lose its northerly component.
This is begun to lessen the lake-induced influence over the low
levels of the environment from west to east progressively. As a
result, low clouds are starting to break up over central Ohio
with this breakup moving eastward slowly into eastern Ohio. In
fact, even an appreciable hole is noted over and just north of
Pittsburgh on GOES-16 imagery. Both the back edge of low clouds
and holes in the low clouds will combine to allow for a general
reducing in clouds over the next several hours with most areas
trending relatively clear overnight.

The slow trend toward clearing overnight along with dewpoints in
the lower to mid 20s should keep temperature readings from going
into free fall overnight. As such, the ongoing forecast for
lows generally in line with current dewpoint readings seems
plausible and will be left unchanged. Fries

&&

.SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY/...
High pressure building in at the surface will lead to a tranquil
Thanksgiving and Friday. Troughing aloft will keep cool
conditions in place, but some temperature moderation is expected
with increased sunshine. By Friday, highs should be back in the
ballpark of average values.

The next high-latitude system will stream through northeast
Ontario early Saturday. This will eventually sweep another
relatively dry cold front through the forecast area. Similar to
yesterday`s system, the moisture starved cold front will result
in light rain, but higher PoPs will be confined to the northern
half of the area. Behind the front, northwest flow gets
established, bringing the possibility of backlash, lake-effect
snow showers.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
Broad troughing will briefly carry into early next week.
Eventually, the strong southwest CONUS ridge will dislodge and
move eastward. This will bring our area another round of
tranquil weather Tuesday with a warming trend towards the middle
of next week. Substantial timing disagreement exists for the
next disturbance middle to late next week, so broad low chance
PoPs were maintained.

&&

.AVIATION /02Z THURSDAY THROUGH MONDAY/...
VFR and borderline MVFR will prevail in stratus for a few hours
before dissipating rapidly under backing flow and building high
pressure. Biggest change from the previous TAF issuance was to
slow to improvement to VFR/eliminate ceilings. Expect high
clouds ahead of the next shortwave trough to pass overhead
tomorrow with no further restrictions expected.

NW wind will shift to w-sw tomorrow and remain under 10kts.

.Outlook...
The next chance for restrictions is forecast with a Saturday
cold front.

&&

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

&&

$$



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