Area Forecast Discussion
Issued by NWS -- Remove Highlighting --
-- Discussion containing changed information from previous version are highlighted. --
FXUS61 KPBZ 241731
Area Forecast Discussion
National Weather Service Pittsburgh PA
131 PM EDT Mon Oct 24 2016
Cooler temperatures today with a few sprinkles or a shower,
especially north and east of Pittsburgh. High pressure will then
keep dry and cool conditions tonight into Wednesday.
.NEAR TERM /THROUGH TONIGHT/...
Afternoon update to issue frost advisory overnight for parts of
eastern Ohio into southern counties of the northern West Virginia
Panhandle. This area has the best opportunity for stratocu to
break out later tonight with light winds. This would give enough
radiational cooling for areas of frost. Other changes to forecast
are minor, and previous discussion follows.
Cold has crossed the southeast ridges, with temperatures to be
steady or fall through the day with 850mb cold advection helping
to keep stratocu across much of the region. With cooler air
pouring over the warm waters of Lake Erie, limited production of
lake- enhanced showers is expected into the afternoon with chance
PoPs primarily north of I-80. A few sprinkles have made their way
south with the cooler air, and have added these basically north
of I-70. Dry and cool high pressure will take temperatures below
the seasonal average tonight as high pressure and subsidence break
.SHORT TERM /TUESDAY THROUGH THURSDAY NIGHT/...
Building surface high pressure will return dry weather to the
area through Wednesday. An upper-level trough will dig into the
western Great Lakes early Wednesday, strengthening the surface low
as it approaches from the west.
Modest isentropic ascent across the warm front will lead to a
gradual increase in clouds by Wednesday morning. Several models
generate qpf with this feature as it pushes north of the area
Wednesday night. Model soundings reveal deeper moisture resides
aloft, with a low-level dry layer. This dry layer, along with a
slower evolution of the parent low, should delay onset of
precipitation. Continuing to hold off PoPs until the surface low
nears Wednesday night.
Likely PoPs have been maintained for Thursday as the deepening low
tracks just to our north. A strengthening of the low-level jet
should increase rain efficiency Thursday. This is noted in fairly high
qpf amounts seen across model guidance, especially the 00z GFS.
For the time being, have stayed at or just below WPC qpf guidance.
.LONG TERM /FRIDAY THROUGH SUNDAY/...
Brief ridging will dry out the forecast Friday, but another trough
will already be approaching from the west. Unsettled weather and
cooler than seasonal average temperatures will hold for the
weekend until the western CONUS ridge begins to break down early
next week. In general, followed close to the Superblend guidance
for construction of the extended period.
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
-- Changed Discussion --VFR with occasionally MVFR stratocu in cold advection will
continue through at least the first half of the TAF period. Lake-
enhanced showers will be situated in the vicinity of KFKL and KDUJ
through the remainder of the afternoon but should do little to
Clouds should begin to scatter out from west to east as a surface
ridge builds overhead and we lose the instability of daytime
heating tonight. However, as the upper trough shifts to the east,
some of the model guidance swings a weak shortwave across the
lakes which may maintain clouds and chances for precip, again
mainly north of PIT. Regardless, VFR conditions should prevail for
much of Tuesday.
W-NW wind with gusts to 20kts will diminish tonight.
.OUTLOOK /TUESDAY THROUGH FRIDAY/...
The next chance for general restrictions will be with Thursday
-- End Changed Discussion --
OH...Frost Advisory from 3 AM to 9 AM EDT Tuesday FOR OHZ039-048-
WV...Frost Advisory from 3 AM to 9 AM EDT Tuesday FOR WVZ004-012.