Area Forecast Discussion
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FXUS61 KPBZ 200025 AAB
Area Forecast Discussion...UPDATED
National Weather Service Pittsburgh PA
825 PM EDT Wed Apr 19 2017
A series of low pressure systems will keep periodic rain chances
in the forecast through late week.
.NEAR TERM /THROUGH THURSDAY/...
-- Changed Discussion --830pm update...no major changes from previous update. Have sped
up the line of showers/storms overnight in line with an
acceleration of the driving upper level wave. As the sun sets,
atmosphere is stabilizing, and with all the clouds today, it
never had much of a chance to get energized. Convection over
Northeast Ohio is showing a weakening trend as it gets close to
my CWA. Have removed the mention of gusty winds, as no strong
wind gusts have been observed as the activity passes over the
observation sites. Kept in the chance for small hail and also
included heavy rain, as brief downpours are possible with any of
Shower activity will increase in coverage this evening as
models have been consistent depicting a line of
showers/thunderstorms this evening along surface boundary
crossing the region from the NW to SE....followed by a MCV which
is progged to cross the region later in the evening to several
hours after midnight. Instability is expected to be minimal but
there is potential for strong wind gusts with storms.
Overnight lows will be mild with cloud cover and continued WAA
ahead of the approaching cold front.
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.SHORT TERM /THURSDAY NIGHT THROUGH FRIDAY/...
Showers and Thunderstorms will be possible again on Thursday
mainly during the afternoon and evening once/if convective
temperatures are achieved which now look to be in the upper 70s.
Activity during the day will be largely dependent on
instability. Any decent breaks in cloud coverage should be
sufficient. The main threat is the potential for strong winds
associated with any storms that have a strong enough updraft to
push cores above drier air progged to be around 20-25kft. Update
the HWO to mention slight risk of damaging winds for western
zones. With near 99 percentile PWAT values by that time will
need to keep an eye on rain rates.
A cold front will cross Thursday night but unfavorable
overnight FROPA timing and waning instability should help limit
potential for severe storms. The SPC marginal outlook still
appears reasonable at this time.
Temperatures will return to seasonal levels by Friday.
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
A trough from the NE CONUS to the Plains should keep rain
chances and cool temps across the area over the weekend as it
approaches and crosses the region, and as a surface low tracks to
our south. Building ridging should return dry and warmer weather
by early next week.
.AVIATION /01Z THURSDAY THROUGH MONDAY/...
Disturbance crossing the area tonight will bring showers and
thunderstorms, especially from HLG on north. MVFR to occasional
IFR visibilities can be expected, and cannot rule out LIFR if a
heavy cell passes over a terminal. Brief wind gusts to 40 knots
will be possible with the strongest storms. MVFR/IFR ceilings
will linger behind this activity later tonight, with the
greatest restrictions north of PIT. Slow ceiling improvement is
expected after sunrise. More storms may begin to develop after
18Z but did not include at this time, with most activity
expected after 00Z.
Restrictions will be possible into Thursday night with low
pressure and a cold front. Widespread restrictions are possible
Saturday and Sunday with strong low pressure.