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000
FXUS61 KPBZ 131658
AFDPBZ

Area Forecast Discussion
National Weather Service Pittsburgh PA
1258 PM EDT Sat Apr 13 2024

.SYNOPSIS...
Light rain showers will finally exit the area just after dawn. Gusty
winds are expected through dawn and a Wind Advisory is in
effect. Much cooler air will settle in today and remain through
Saturday. Thunderstorm chances return again on Sunday.

&&

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

- Dry with clouds clearing but breezy today.
- Wind Advisory remains in effect for Eastern Tucker County, WV
-----------------------------------------------------------------

No changes needed with the early afternoon update...

High pressure building in from the south is introducing drier
air and slowly eroding cloud cover from west to east this
morning while strong 11-13 dam 12 hour height rises approach
from the west. Northwest flow aloft is maintaining a deck of
lake induced stratocu from about the PA/WV border on east.
Expect that these clouds will clear slowly through the day with
subsidence drying out the boundary layer, but hold on long
enough to keep temperatures cooler (low to mid 50s) across
western PA while eastern OH has a 40-70% chance of tapping into
the 60s as the axis of an 850 mb ridge builds. If clouds can
clear a bit quicker which latest hi res ensemble guidance shows
as a possibility, highs may need to be increased a couple
degrees further east.

The gradient will continue to be in place and wind
gusts will still continue through the day. By 18z, there is a
good 50% to 60% confidence that winds will still gust above
30 mph. The Advisory will remain over Eastern Tucker through
most of the day where 60-80% probability for gusts >46 mph
continue into this evening. Gusts will diminish after sunset
save for the ridges with gusts to 30 mph still possible
overnight. Warm advection tonight with weak southwest flow in
building ridging will hold lows a couple degrees above normal.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY/...
KEY MESSAGES:

- Thunderstorm chances return Sunday with potential for some strong
  to severe.
-------------------------------------------------------------------

Come Sunday, a warm front is progged to pass through in the morning
placing our area in the warm sector of low pressure just to our
north. Surface flow backs more southerly and warm, moist advection
pulls temperatures into the 70s with greatest confidence south and
west of Pittsburgh. Dew points will rise into the mid to upper
50s allowing for sufficient destabilization by afternoon ahead
of an approaching cold front. NBM probabilities for CAPE
exceeding 1000 J/kg rise up to 70-80%, highest across eastern
Ohio. A belt of 40-50 knot westerly low level flow veering more
with height atop southwest flow at the surface looks to support
shear values for thunderstorm organization with the cold front,
some potentially strong to severe. Most of the shear and
curvature noted in hodographs occurs within the lowest 1-3 km
and deep layer shear is weaker. Some question will come into
play with warm advection occurring aloft that may mute low level
lapse rates, though an elevated mixed layer should support at
least some extent of a hail threat. SPC has the area in a
Slight Risk (2/5). It is looking like that storm motion will be
more progressive but any additional rainfall less than 48 hours
from the ending of the last event will likely prolong recovery
from flooding during the last event.

With the only minimal uncertainty being driven by the progression of
the upper trough into Monday, confidence is high that the front will
clear the area by the morning hours and, aside from some low
probability shower chances south of I-70, the day should be dry.
Ensembles aren`t very bullish on intrusion of cooler air in the wake
of the front as an 850 mb ridge quickly builds in its wake and
temperatures remain above normal.

&&

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

- Temperatures climbing well above average.
- Rain chances return Tuesday and linger into mid- week.
-------------------------------------------------------------------

Above normal temperatures will be the theme into next week as brief
upper ridging builds and southerly return flow promotes warm
advection kicking temperatures well above average with ensemble
probability for >70F in excess of 70% through Thursday. More
uncertainty comes into play with precipitation chances as an upper
low ejects across the Midwest late Monday. Current ensemble
consensus tracks a surface low through the Great Lakes and returns
rain to our region by Tuesday, but the uncertain and unsettled
progression of the upper level pattern looks to hold precipitation
chances around through the end of the week.

&&

.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
Skies will continue to clear from west to east through the
afternoon as high pressure builds in from the west. Gusty WNW
wind will continue through the afternoon with a tight pressure
gradient, and lessen this evening the gradient relaxes under
the building high.

.Outlook...
Restrictions with showers and possibly severe thunderstorms are
expected late Sunday with a crossing cold front. VFR is expected
under high pressure Monday and most of Tuesday. Restriction
potential returns late Tuesday and Wednesday with approaching
low pressure.

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
PA...None.
OH...None.
WV...Wind Advisory until 6 PM EDT this evening for WVZ514.

&&

$$

SYNOPSIS...MLB/Shallenberger
NEAR TERM...MLB/Shallenberger
SHORT TERM...Shallenberger
LONG TERM...MLB/Shallenberger
AVIATION...88