Scientific Forecaster Discussion
fxus61 kpbz 220255
Area forecast discussion
National Weather Service Pittsburgh PA
1055 PM EDT sun Apr 21 2019
high temperatures will be in the 60s and 70s through the week. The
next chance for rain arrives Tuesday afternoon.
Near term /through Monday/...
other than relatively minor changes to sky cover grids, no changes
were needed at this time.
This 24 hour period will be dry with surface high pressure briefly
moving into the region. With skies beginning to clear tonight,
temperatures should be similar to last night's values. A sunny day
tomorrow will allow highs to climb 15 to 20 degrees from today's
values, reaching the mid 60s to lower 70s.
Short term /Monday night through Wednesday/...
have maintained a dry forecast for Monday night and Tuesday morning,
with rain moving in from northwest to southeast. Instability should
be enough to allow for a chance of thunderstorms, although confidence
was not high enough to allow the thunderstorm mention to reach the
likely level of showers. While the front may slide in slightly slower
than previously expected, likely pops have been expanded to nearly
all locations Tuesday night. The previous shift mentioned in their
afd that the models were more bullish on pushing the boundary just
south of the region on Wednesday, and this trend has continued with
the 12z model runs. As a result, have lowered pops across nearly
locations for Wednesday, although the chance for rain cannot be
completely eliminated. Highs will rise another 5-10 degrees Tuesday
compared to Monday, but will fall back into the 60s everywhere
Wednesday behind the cold front.
Long term /Wednesday night through Sunday/...
again, the previous discussion mentioned the boundary being south of
the region during the Wednesday/Thursday time period. While the 12z
models showed this trend continuing Wednesday night, and the forecast
has been made dry, the European model (ecmwf)/GFS/gefs all show the boundary nudging
its way back to the north on Thursday, and have maintained chance
showers for Thursday, Thursday night, and Friday. High pressure will
move over the Great Lakes and definitively clear the boundary Friday
night. While models show a weak low pressure system moving north of
the region Sunday, have decided not to include pops at this time.
Temperatures should be a few degrees above normal through the period.
Aviation /03z Monday through Friday/...
MVFR cig restrictions will persist overnight as an upper low over
the area will slowly transition east with improvement to VFR Monday
morning as ridging builds in from the west.
restrictions are likely once again Tuesday night with a passing
shortwave and associated cold front.