460
FXUS61 KPBZ 022205
AFDPBZ

Area Forecast Discussion
National Weather Service Pittsburgh PA
605 PM EDT Sun Jun 2 2024

.SYNOPSIS...
There is a potential for early morning fog Monday. Mainly dry
weather is then expected through Tuesday, with widespread rain
returning Wednesday. Periodic rain chances are then expected
into the weekend. Temperatures remain above average through much
of the week, cooling slightly into the weekend.

&&

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

- Shower coverage will diminish into the late evening.
- There is a potential for fog between 3am and 8am Monday
  morning.
- Dry weather overnight, minus a few stray showers in the
  ridges.
--------------------------------------------------------------

Evening Discussion: Weak lift has kept precipitation chances low
and light across the region this evening. Despite a blanket of
low-lvl cumulus across eastern OH/ western PA, fog potential
will remain elevated with sufficient boundary layer moisture and
light winds overnight. However, confidence is currently not
high on the need for a widespread Fog Advisory.

Previous Discussion:

Rain should end this evening as ridging begins to build. Any
lingering overnight showers will be confined to the higher
terrain.

The lack of notable dry advection behind the system will
increase the probability of fog as clouds begin to clear
overnight.

Limited insolation and rain will keep afternoon highs in the
upper 60s to lower 70s. Temperatures will fall into the
60s/upper 50s overnight.

&&

.SHORT TERM /MONDAY NIGHT THROUGH TUESDAY/...
KEY MESSAGES:

- Dry weather continues through Monday.

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

Upper ridging will build over the region Monday and Tuesday,
keeping mostly dry for those days. CAMs do continue to hint at
an isolated shower/thunderstorm or two with daytime heating,
primarily over the ridges, so have left minimal POPs in each
afternoon for those areas. Most of the area will remain dry.

Temperatures will warm to above normal with increasing heights.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
KEY MESSAGES:

- More organized showers and thunderstorms are expected
  Wednesday into Thursday.
- Periodic showers with cooler conditions are expected into the
  weekend with a slowly crossing upper-level low.

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

An unsettled period is expected Wednesday into the weekend as an
upper level low slowly crosses from Manitoba through the Great
Lakes.

The most focused period of convection associated with this
trough/low is expected Wednesday afternoon and evening. Strong
southerly flow Tuesday night and Wednesday should lead to
temperatures in the mid-80s by Wednesday afternoon, with dew
points approaching 70F. This should contribute to moderate
instability across the region and convection developing in the
warm sector sometime during the afternoon/evening timeframe. A
more focused line of storms is then possible as the front
crosses into the overnight. With 20-30kts of deep-layer shear,
this environment may support a low-end severe weather threat.

Brief clearing is expected behind the front Wednesday night into
Thursday, but the upper-level low will dig across the Great
Lakes Thursday and Friday and into New England by Saturday. This
will keep cooler and showery conditions in the forecast for the
second half of the week. While there is low confidence on
pinpointing the best timing of these showers each day, ensembles
do agree on the general showery pattern persisting into the
weekend.

&&

.AVIATION /22Z SUNDAY THROUGH FRIDAY/...
Only isolated showers remain as a weak shortwave crosses the
region, with limited support for afternoon rejuvenation. Thunder
chances remain quite low due to suppressed instability, but if
one occurs, it would likely be in eastern Ohio.

Ceiling will hold at MVFR levels, with continued isolated drops
to IFR through the afternoon. As showers pull to the east this
evening with the departing shortwave, ceilings may lift to VFR
levels for a brief period at several terminals.

The forecast for tonight retains some level of uncertainty.
Lingering low-level moisture points to the possibility of
stratus and fog overnight, but the depth of any fog will depend
at least somewhat on the amount of clearing that can occur
during the late evening and early overnight period. NBM guidance
is suggesting in the neighborhood of 25-45% probability of IFR
conditions across the region during the predawn hours. Actually
think that this might be a bit underdone and have included IFR
conditions at most terminals between 07Z and 13Z, but if
clearing is a bit less than expected, MVFR may end up being the
dominant category.

Whatever restrictions are in place will largely end by 13-14Z as
surface ridging and daytime heating mix out the low clouds and
fog, bringing back VFR conditions.


.Outlook...
The next low pressure system is favored to arrive Wednesday
afternoon and evening, promoting fairly widespread showers and
thunderstorms.

&&

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

&&

$$

SYNOPSIS...Rackley
NEAR TERM...Hefferan/Rackley
SHORT TERM...Rackley
LONG TERM...Rackley
AVIATION...CL