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FXUS61 KPBZ 231207
AFDPBZ

Area Forecast Discussion
National Weather Service Pittsburgh PA
807 AM 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 /UNTIL 6 PM THIS EVENING/...
KEY MESSAGES:

- Showers, isolated thunderstorms expected today.
- Temperatures remain above normal.
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A batch of warm advection driven showers has now mostly crossed
the region this morning. Rainfall totals through 8am have
largely been light with up to a couple tenths across western
PA/eastern OH and slightly more in northern WV where some more
steady rain fell coincident with fumes of elevated instability with
up to a half an inch locally. We will sit in a narrow open warm
sector as depicted on latest mesoanalysis for the next couple
hours ahead of an approaching cold front that will slowly
progress eastward through the region this morning. Most of the
deep moisture and best upper level support will be ahead of the
front, and the atmosphere will not destabilize very much with
thick cloud coverage. That said, there will be increasing wind
shear, so thunderstorms cannot be completely ruled out.

The front will exit to the east early this afternoon, and there
will be brief ridging aloft as the early morning shortwave moves
over eastern PA. Would expect the rain threat to lessen this
afternoon, and we may dry out enough to lose the lower cloud
cover as well.

Above normal temperatures are anticipated today.

&&

.SHORT TERM /6 PM THIS EVENING 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 SUNDAY/...
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 /12Z 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...22/MLB
SHORT TERM...22
LONG TERM...MLB/Milcarek
AVIATION...Hefferan/Milcarek