097
FXUS61 KPBZ 231718
AFDPBZ

Area Forecast Discussion
National Weather Service Pittsburgh PA
118 PM EDT Mon Sep 23 2024

.SYNOPSIS...
An active weather pattern is expected through most of the week.
Even with the clouds and threat of rain, temperatures will
remain warm through the week.

&&

.NEAR TERM /THROUGH TONIGHT/...
KEY MESSAGES:

- Scattered showers along a passing cold front this afternoon.
- Dry period likely for most of the overnight.
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In the wake of the morning warm front passage, we`ve sat briefly in
the warm sector ahead of an approaching cold front that will slowly
progress eastward through the region this afternoon. Most of the
deep moisture and best upper level support will be ahead of the
front, and satellite observations don`t indicate much in the way of
breaks in the clouds, so little atmospheric recovery will be
possible ahead of the cold front. With fumes of instability to work
with (hi res ensemble mean ~500-600 J/kg), won`t entirely rule out a
rumble of thunder, but this should largely take on a widely
scattered showers nature at most; additional accumulation will
be light with the highest chance for >0.10" in the ridges.

Behind the front, drier mid-level air works in and we should mostly
lose the precip chances with for most of the overnight, save the
higher elevations where upslope flow with lingering low-level
moisture may provide some drizzle. Some areas of fog and low stratus
are also on the table, especially where rain fell today, with
sufficient low-level saturation. With the cloud coverage and
elevated dew points, lows will fall to the low to mid 60s, some 10
degrees above normal.

&&

.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
KEY MESSAGES:

- Rain chances continue through mid-week.
- Temperatures remain warm.
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Height falls are expected on Tuesday as another shortwave trough
swings through the region during the afternoon. This wave looks
to be stronger than today`s and with southwest flow aloft, ahead
of an upper low that will dig into the midwest, gulf moisture
will stream in over the region. Another round of showers and
possibly thunderstorms is expected Tuesday.

Temperatures Tuesday will be above normal again.

Little change on Wednesday as a large trough settles in over the
Midwest. The area will remain on the eastern side of the upper
level system, meaning gulf moisture will continue streaming
northward over the region. Upper level waves will swing through
the trough and eject northeastward in the southwest flow aloft.
This will mean the threat for showers and possibly storms will
continue through Wednesday.

Temperatures Wednesday remain above normal.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
KEY MESSAGES:

- Uncertainty increases greatly for the latter half of the week with
  potential tropical low interaction.
- Rain chances will continue through the end of the week.
-------------------------------------------------------------------

A weak boundary may pass through the area sometime Thursday,
but seeing significant spread in the ensembles on the timing
which will impact when we lose the rain chances. The central
CONUS trough digs deeper on Thursday and looks to cut off from
a northern stream trough, but ensemble clusters exhibit quite a
bit of disagreement here. A faster solution cuts off rain
chances overnight Wednesday night while others suggest a slower
progression and maintain the rain all the way through Thursday
night. Meanwhile, the remnants of a potential tropical system in
the Gulf may interact with the trough.

The highest probability scenario is that the northern stream
trough is through by late week. A few ensembles still lag the
passage, with some higher QPF totals possible across the
southeastern half of the forecast area. Another cluster of
ensembles has the system moving into the Midwest behind the
trough. Will stick with NBM given all of the uncertainty.

&&

.AVIATION /17Z MONDAY THROUGH FRIDAY/...
A slow moving cold front is currently situated just west of
ZZV. A number of sites have already fallen to IFR/MVFR/LIFR with
passing rain from our overnight disturbance. However, with
rainfall rates weak over the last 12 hours and dry air noted in
the PIT 00Z sounding with lingering across the region, creating
VFR conditions noted in some spots despite the rain showers.

Cigs are expected to bounce between VFR/MVFR/IFR between 14Z to 18Z
as warm air returns from the southwest with incoming disturbance
over Missouri.

Cigs are forecast to lift to VFR after 18Z, save DUJ and FKL,
but coverage is expected to remain broken.

Ample low moisture and reinforced saturation tomorrow night
likely means another night of at least MVFR restrictions are
ahead for most ports. More rain arrives Tuesday.

.Outlook...
Rain and restriction chance continues into Tuesday with another
low pressure center. Unsettled weather is then possible through
mid-week.

&&

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

&&

$$

SYNOPSIS...22
NEAR TERM...MLB
SHORT TERM...22
LONG TERM...MLB/Milcarek
AVIATION...Hefferan/Milcarek