Area Forecast Discussion
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FXUS61 KPBZ 011747
Area Forecast Discussion
National Weather Service Pittsburgh PA
1247 PM EST Wed Mar 1 2017
The advance of a strong cold front has brought showers and
thunderstorms to the Upper Ohio Region for today. Much cooler
temperatures will then last through much of the weekend.
.NEAR TERM /THROUGH TONIGHT/...
The third batch of rain supported by the upper shortwave us
swiftly pushing east. Currently, greatest severe weather threat
remains SE of PIT where better instability and shear are.
Moderate rain will continue for the next hour or two before a
break occurs with subsidence ahead of the cold front currently
lagging in Indiana. Will hold on to the flash flood watch given
the moderate rain still over the CWA and on-going flooding.
Visible imagery shows clearing west of the area and
near term hi-res models forecast convection to develop and cross
the region in the late afternoon. The strength of the line of
progged convection is uncertain at this time and will depend on
how unstable the lower atmosphere can get before the front
arrives. Nonetheless, strong wind gusts are likely to occur if
thunderstorms develop due to significantly strong wind shear.
Late day cold frontal passage will end the severe weather
threat and return cold and snow showers chances to the region.
Wind gusts behind the front are expected to reach advisory
criteria as cold advection at the top of the boundary layer
improves mixing. A wind advisory will likely be issued for
tonight once current convection moves out of the CWA.
.SHORT TERM /THURSDAY THROUGH FRIDAY/...
After the FROPA, upper troughing, cold advection, and limited
lake and terrain enhancement should result in scattered snow
showers through Thursday as temperatures return to sub average.
Clipper system which has been well-advertised by the models
digs over the region on Thursday night with some accumulating
snow expected. Snow showers should linger and possibly
reenhance Friday afternoon with steep low-level lapse rates.
Accumulation rates may initially struggle with warm ground, but
cannot rule out the eventual need for a winter weather advisory
in at least the ridges.
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
Troughing pattern in the wake of the clipper Saturday
transitions to a more zonal/flat ridge pattern for Sunday and
Monday, and then a more amplified pattern once again by Tuesday
with another trough/front approaching. Mainly dry weather for
Saturday may be followed by a weak disturbance on Sunday, and
then better precipitation chances thereafter as southwest flow
and moisture ramp up again. Below average temperatures at the
start will rise moderate early in the new week.
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
The first round of precipitation is moving east of the area as
of this writing. Lingering MVFR ceilings for the next hour
should rise to VFR during the next few hours. The cold front is
expected to move across the area between 21Z and 03Z, with a
broken line of thunderstorms accompanying it. Handled with VCTS
for now, as exact timing is still a bit questionable and any IFR
restrictions from these storms should be brief.
Winds should pick up again behind the front, with gusts to 40
knots out of the west possible. Wind gusts will continue through
the night, slowly diminishing late, as MVFR or low-end VFR
ceilings linger. Post-frontal rain showers should change to snow
showers overnight before mostly ending towards morning. VFR
ceilings may redevelop at several terminals by 18Z as winds
continue to diminish.
Periodic restrictions are likely through Friday as cold low
pressure crosses the region.
MD...Flash Flood Watch until 8 PM EST this evening for MDZ001.
OH...Flash Flood Watch until 8 PM EST this evening for OHZ057>059-
PA...Flash Flood Watch until 8 PM EST this evening for PAZ029-031-
WV...Flash Flood Watch until 8 PM EST this evening for WVZ003-004-