006
FXUS61 KPBZ 240758
AFDPBZ

Area Forecast Discussion
National Weather Service Pittsburgh PA
358 AM EDT Tue Sep 24 2024

.SYNOPSIS...
An active weather pattern is expected through most of the week
with a Marginal Risk for severe weather today south and west of
Pittsburgh. Even with the clouds and threat of rain,
temperatures will remain warm through the week.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
KEY MESSAGES:

- More widespread showers/storms possible today.
- Strong to severe storms remain a threat.
-------------------------------------------------------------------

A surface warm front will slowly move northward through the
region later today. The front is associated with a surface low
moving across the midwest. A shortwave, swinging northeastward
on the eastern side of the digging midwest trough, will help to
push the front through the region. Showers and storms are
expected to develop along the front. The threat for strong to
severe storms will continue, particularly over portions of Ohio,
SW PA (south of PIT), and northern WV. The greater threat
exists over these locales due to an increasingly unstable
atmosphere that will occur in the warm sector south of the
surface boundary. Along with the destabilization, wind shear
will strengthen this afternoon, values will approach 50kts close
to and south of the front. The question for today is can
convection initiate. Models are all in good agreement that there
will be plenty of cloud cover today. Additionally, warm air
advection aloft will create a cap which will work against
parcels reaching the LFC. The strengthening shear will intensify
any updrafts in storms that do develop which may be enough to
push through the cap. The current marginal risk area from SPC is
focused over the portion of the region that will see the most
instability, so this continues to look reasonable. Model
hodographs would support rotating storms, so if strong storms do
develop, this will be a concern.

A wide range of temperatures are expected today, those in the
warm sector, upper 70s to lower 80s, and those north of the warm
sector, upper 60s to lower 70s.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
KEY MESSAGES:

- Rain chances continue through mid-week.

-------------------------------------------------------------------

The digging midwest trough is favored to cut off into a closed
low across the south-central CONUS with some uncertainty in the
timing and depth of a northern stream trough north of the Great
Lakes on Wednesday. Rain chances will continue with rounds of
shortwaves and general troughiness in southwest flow aloft.
With generally weaker forcing, 24 hour totals ending Thursday
morning look on the lighter side, mostly less than 0.5", though
a much lower probability solution with a deeper, phased trough
exists with higher amounts.

Temperatures through mid-week will be cooler owing to increased
cloud coverage and precipitation.

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. Ensemble clusters exhibit
quite a bit of disagreement at this point with how the upper level
pattern evolves.

&&

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

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

The central CONUS trough may interact with the remnants of now
PTC 9 as it moves inland out of the Gulf. Meanwhile, the
northern stream trough will be sliding across the Northeast
states. Ensemble clusters all show that the remnants will be
absorbed by the trough but with much uncertainty after that.

The highest probability scenario at this time is that the northern
stream trough deflects the remnants off to our west and rain chances
here are lower. There are potential wetter solutions with a track
further east, but until we get a better idea on the evolution, will
stick with NBM given all of the uncertainty which advertises low end
rain chances into the weekend.

&&

.AVIATION /08Z TUESDAY THROUGH SATURDAY/...
Ample cloud coverage is expected to keep IFR visibility
restrictions to a minimum, but a brief drop to MVFR visibility
overnight cannot be ruled out with ample low-level moisture and
air near saturation, particularly for DUJ and perhaps FKL.
Winds are generally expected to remain light and out of the
southeast. A passing wave will allow for some light rain
locally, with more substantial amounts for MGW through sunrise.
Save FKL/DUJ, ceilings are generally expected to remain VFR
though brief drops in cigs to MVFR are possible in isolated
showers. As for FKL/DUJ, there is 40% to 60% chance of IFR cigs
and may continue through the period with continued rain chances.

Into today, convective coverage is expected to increase with
increasing instability. Flow will accelerate slightly out of the
southeast. Storms will remain possible through the day, but
TAFs attempted to capture the most favorable window for now.
The environment is supportive of damaging wind, hail, and
isolated tornadoes, but intensity is still highly questionable
with uncertainties in instability. Restrictions are likely in
any more intense storms. Uncertainties in instability and
mixing also truckle down to cigs, which may hover around the
VFR/MVFR range, depending on how much heating the area can tap
into during the day.

Deterioration is expected tonight, particularly for areas which
it has rained. Ceilings are expected to lower to the MVFR/IFR
range once again. Winds lighten out of the southeast.

.Outlook...
Some improvement is expected Wednesday, with a 80% chance of
VFR, though very isolated showers and storms may bring
temporary cig/vis drops. Restriction chances increase Thursday
morning, before VFR returns to close out the work-week.

&&

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

&&

$$

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