Area Forecast Discussion
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FXUS61 KPBZ 241813
AFDPBZ

Area Forecast Discussion
National Weather Service Pittsburgh PA
213 PM EDT Wed Aug 24 2016

.SYNOPSIS...
A couple of crossing disturbances will return rain chances to the
Upper Ohio Valley Region for the overnight and Thursday.

&&

.NEAR TERM /THROUGH TONIGHT/...
High clouds have continue to stream toward the area today ahead of
a fairly compact system easily discernible over northern Illinois
at this hour. This system is attempting to track right into the
apex of a mid-level ridge anchored over the Appalachians, which
the models indicate will show little propensity of budging over
the period. As a result, the best forcing for ascent will be
shunted a bit to the north of the area as it attempts to track
eastward. However, a gradual increase in layer moisture overnight
toward morning combined with an increase in DPVA will allow for
the return of shower chances overnight.

With the increase in cloud cover as well as southerly flow in
place over the area combined with much warmer temperatures this
afternoon than we have seen in a couple days, a strong radiational
cooling night is not expected. Due to the floor these
aforementioned phenomena will place under temperature falls, lows
generally straddling 70F seem fairly plausible. Fries

&&

.SHORT TERM /THURSDAY THROUGH SATURDAY/...
The northern zones are progged to be in a favorable environment
to experience numerous convection Thursday as a front sags
southward. Fueled by day time surface heating and increased flow
aloft, some thunderstorms may reach severe criteria, but overall
coverage and intensity should be marginal across the region as
instability remains limited by very warm mid level temperatures.

Precipitation chances are projected to wane on Friday as surface
high pressure builds in the wake of a weak front. Given the
strength of the upper ridge, southward frontal penetration is
questionable, but will generally persist with a dry forecast through
Saturday as per the latest deterministic trends as flow becomes
zonal. Warm weather will continue as zonal flow across the northern
ridge periphery shunts warm air across the region.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
Flow is expected to back to a southwesterly direction as an upper
high enhances and shifts towards the Mid-Atlantic. As a result of
the strengthening ridge, anonymously high surface temperatures
and upper heights are predicted by ensemble models and have led
to higher confidence in raising forecast temps early in the
period. Overall, hot and humid conditions can be expected in the
beginning of the long term until the passage of a shortwave on
Monday provides some relief from the heat. POPs were maintained in
association of the aforementioned shortwave as per the latest
Superblend guidance.

&&

.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
High clouds will continue to increase through the evening, even as
diurnal cumulus fades. Showers will encroach from the west
overnight, however coverage is questionable and restrictions from
them also questionable due to copious coverage of high clouds. The
forecast was built without visibility/ceiling restrictions with
the best chance of showers and even a thunderstorm being during
the daytime hours Thursday. Fries

.OUTLOOK /THURSDAY THROUGH SUNDAY/...
Periodic restriction chances should persist through Friday with
the approach and passage of a cold front.

&&

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

&&

$$



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