Area Forecast Discussion
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FXUS61 KPBZ 231332

Area Forecast Discussion
National Weather Service Pittsburgh PA
932 AM EDT Tue May 23 2017

High pressure will provide a dry Tuesday with seasonal
temperatures, but unsettled weather will start to return on


A cirrus shield well out ahead of a system riding up the Middle
Atlantic will continue to push northeastward through much of the
day. Satellite depictions of this field look far more impressive
than it likely is as model time-height sections reveal a fairly
narrow window of saturation aloft. Thus, it seems reasonable to
expect a fairly translucent high cloud shield across the
majority of the area through the day. In general, a partly sunny
forecast was thus featured, except in the ridges and points
nearby where clouds may be a bit thicker.

Deep moisture associated with the system moving up the coast
really never looks to make retrogressive progress into the CWA
on Tuesday. The upper jet axis likewise would not favor it doing
so as it aligns generally in line with the Laurel Highlands.
Thus, any rain showers seem unlikely to make it west of maybe
Tucker/Garrett County on today and tonight. High clouds will be
around in the rest of the CWA, however overall dry weather will
continue. Fries


Generally dry conditions will continue to prevail through the
overnight and into Wednesday morning as the first system along
the Middle Atlantic tracks farther from the area. Beyond that
time, the upper level pattern looks to evolve very slowly with
general pattern amplification being key to the eventual shifting
of the pattern by the second half of the week.

Model solutions have had substantial difficulty over the past
few days managing the depiction of the digging and deepening of
the mid/upper lower from the upper Mississippi Valley toward the
Ohio Valley. However, the 00z cycle tonight has favored a timing
of deeper moisture into the area generally around Wednesday
afternoon across much of the area. This will allow for an
unusual temperature spread with the warmest readings northeast
and coldest southwest on Wednesday. However, while forcing with
the incoming system is impressive, instability is not. Thus,
while moderate rainfall amounts will be possible, thunder
chances remain rather subdued.

The upper low takes its sweet time migrating across the area
from Wednesday night into Friday. This will bring a decent chunk
of 500 mb cold air over the CWA. As such a lowering of
convective temperatures will mean abundant clouds and shower
chances remaining across the CWA through the remainder of the
work week. Temperatures meanwhile will be below normal. Fries


While the slow-moving upper low will have moved northeast of the
area by Friday night, and upper ridging will be briefly holding
sway over the area, the interlude of quiescent conditions will
be relatively short. The mid-level ridge axis looks to quickly
kick east of the area on the consensus with deeper southwesterly
flow aloft returning for the weekend. This will bring Gulf
moisture toward the area again, resulting in increasing
temperatures and humidity as it occurs.

Shower chances will increase through the weekend as deep
moisture encroaches, however warmer temperatures should prevail
at least until early next week as the highly amplified pattern
continues to persist, and the next sprawling upper low looks to
take until at least Tuesday to arrive in our area. Fries


VFR conditions are expected through the TAF period under low
level ridging as mid/high clouds increase on the nrn side of a
surface low tracking toward the Mid Atlantic region.

Winds will remain light and from the east-southeast through the

Restrictions are likely late Wed thru Thu, and are possible Thu
night thru Sat, with crossing low pressure.




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