Area Forecast Discussion

Pittsburgh, PA

Forecast Discussion for PBZ NWS Office
FXUS61 KPBZ 222332

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

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


Current regional satellite imagery shows expansive cloud cover
across the area, although some cracks are starting to form. This
remnant moisture left in the wake of last night`s cold front
will take some time to erode. The forecast will hold clouds
through the late evening until low- level flow can sufficiently
back and bring drier air in from the west. Temperatures will
likely hold steady through early evening, before beginning their
march downward.

As mentioned above, appreciable clearing is expected to be
rather slow tonight. This, and dewpoint values currently just a
few degrees away from their expected low values tonight, will
provide a floor for tonight`s low temperatures. Values are still
expected to be about 10 degrees below average.


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.


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.


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.

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





NWS PBZ Office Area Forecast Discussion