Scientific Forecaster Discussion
fxus61 kpbz 161629
Area forecast discussion
National Weather Service Pittsburgh PA
1229 PM EDT Mon Sep 16 2019
a passing shower is possible today as a weak cold front crosses the
region. Dry weather and warm temperature are expected for the rest
of the week.
Near term /through tonight/...
steep low-level lapse rates have been infused with a plume of
moisture from Lake Erie, supporting ongoing showers north of I-80
this morning. These have waned during the last couple of hours, but
clouds are likely to persist amid the lingering instability and
A weak cold front currently in far nwrn PA will advance swd this
afternoon and evening, and may support a slight upswing in coverage
of showers as renewed lake moisture is supplied in its wake. However,
high pressure will build quickly as an upper-level ridge amplifies to
the west, bringing veering wind and increasingly dry air to end any
showers in the ridges by mid-morning Tue at the latest.
Short term /Tuesday through Thursday night/...
the amplifying upper ridge will build ewd through the week with very
high confidence, leading to strengthening sfc high pressure, drying
low levels and strong insolation. Apart from the Post-frontal air
mass on Tue, temperature is likely to be in the lower 80s, well-above
the average of low-mid 70s.
Long term /Friday through Sunday/...
- above-average temperature
- no sign of measurable rain until late in the weekend
Mid level anticyclone across the Midwest will be the main weather
player for the extended. 500 mb heights climb well into the 580s, which
spells temperature greater than where they should be for mid-September.
Daytime maxima climb as we head through the week, as will the
humidity. Saturday is shaping to be the warmest day as lower to mid
80s are predicted. As the ridge breaks down Sunday, a weak front is
projected to cross the area Sunday night into Monday.
Aviation /16z Monday through Friday/...
high confidence forecast save for cigs and vis after 8z where they
could be lower than forecast especially at Beaver Falls, Wheeling,
Morgantown, and Zanesville.
Scattered to broken high based cu will be the story through the
evening hours, before the front moves through and clears things out.
There will be short windows of broken clouds this afternoon. Any
isolated showers that develop will be brief and at worse drop an
Airport to MVFR, but given confidence on coverage, not including any
mention of precip in the forecast.
With residual moisture and light wind, stratus and/or fog could
develop after 9z. For now, hinted at possible IFR conditions, but
will see how future model runs unfold before making it prevailing.
Most prone sites will be closer to the where the front is across West
Virginia terminals and Zanesville. Surprisingly, the higher frequent
IFR sites of fkl and duj should have enough dry air in place to
offset fog development.
no widespread IFR weather is predicted