840
FXUS61 KPBZ 220606
AFDPBZ

Area Forecast Discussion
National Weather Service Pittsburgh PA
206 AM EDT Sun Sep 22 2024

.SYNOPSIS...
Very warm weather is expected through the weekend. Fog is
possible overnight and early Sunday morning.  A wetter pattern
is becoming increasingly likely next week.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
KEY MESSAGES:

- Clearing skies late with areas of fog overnight.
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Maintained temperatures and dew points from prior update. Fog
remains a possibility tonight, particularly for areas where it
rained and in insulated river valleys as temperatures approach
saturation. Lows are expected to bottom out a few degrees above
average. Could not rule out a localized dense fog SPS or
advisory by daybreak, but will continue monitoring visibility
observations, satellite, and webcams before making a new
product issuance.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY NIGHT/...
KEY MESSAGES:

- Dry with above average temperatures on Sunday.
- Rain chances (yes, rain chances) increase starting Monday.
-------------------------------------------------------------------

A shortwave ridge axis will slide overhead in the wake of the
departing disturbance from Saturday with height rises and warm
advection supporting temperatures again into the 80s, warmest in
eastern Ohio, with 90 not out of the question there. High clouds
will increase in the evening from the west ahead of approaching low
pressure.

The main takeaway headed into the next workweek is that we are
finally seeing appreciable chances for beneficial rain. The upper
ridge axis will quickly be shunted east by an approaching trough,
and a shift to southwest flow aloft on its backside will open the
door for better moisture to work its way into the region. Clustered
ensembles exhibit pretty good agreement through Tuesday night with
just some strength and timing differences of the progression of the
responsible upper trough. Rain chances will increase Monday morning
as surface low pressure progged to be across Michigan pulls a trough
through the area. Ensemble probability for >0.5" of rain through
Tuesday night is still high (up to 80%) and a 50-70% chance of >1".

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
KEY MESSAGES:

- Rain chances increase Monday and Tuesday with a widespread,
  beneficial rainfall possible.
- Rain chances continue for the latter half of the week but
  confidence in amounts is low.
- Temperatures closer to average through the week.
-------------------------------------------------------------------

Uncertainty then increases significantly with ensembles
becoming much more spread on how the upper pattern evolves. The
majority consensus is that the Ohio Valley remains in a
troughing setup with significant differences on placement and
amplitude of the trough, but even one solution is attempting to
establish a ridging pattern. For continued beneficial rain, we
would want the solution(s) that sets up a trough deeper and off
to our west. Long story short, scenarios exist where additional
beneficial rain sticks around for the latter half of the week,
and scenarios exist for a drier period.

Despite this uncertainty, at least continued low precipitation
chances are appropriate through the end of the work week. 72 hour
precip totals have seen a slight eastward nudge in the past several
ensemble runs with probability for another >0.5" from Wednesday
through Saturday morning at 40-50% east of Pittsburgh and 20-40%
further west. A few high end, low probability scenarios exist
pending tropical influence. All told, the wetter pattern next week
holds some promise to at least somewhat mitigate the ongoing
drought. Temperatures moderating to seasonable levels (for daytime
highs at least) will help as well.

&&

.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
Already beginning to see patchy dense fog developing over areas
that saw the most rain today, primarily along the higher terrain
and across northern WV. Visibilities at DUJ/FKL have dropped to
IFR or lower and LBE is down to MVFR to start the 06Z TAF period.
Expect the fog to gradually become more expansive and dense in
these areas through the rest of the night, with visibilities at
the aforementioned terminals (and at MGW) deteriorating through
sunrise. Dense fog is less likely farther west, though
PIT/AGC/HLG could still see a brief period at MVFR/IFR right
around sunrise. Fog should lift everywhere by 14Z, with VFR
conditions expected the remainder of the day under building
high pressure.

.Outlook...
Rain and restriction chance increase late Sunday night into
Monday with another crossing cold front. Unsettled weather is
then possible through mid-week.

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
PA...None.
OH...None.
WV...None.

&&

$$

SYNOPSIS...Milcarek
NEAR TERM...Milcarek
SHORT TERM...MLB
LONG TERM...MLB
AVIATION...Cermak/Rackley