-- Discussion containing changed information from previous version are highlighted. --
344
FXUS61 KPBZ 061120
AFDPBZ

Area Forecast Discussion
National Weather Service Pittsburgh PA
720 AM EDT Mon May 6 2024

.SYNOPSIS...
A break from widespread showers today, with the focus for
activity mainly south of Pittsburgh. Unsettled weather and warm
temperatures for the rest of the week.

&&

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

- Convection may redevelop south of I-70 this afternoon/evening,
  north of a stalled frontal boundary.

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A cold front will drift south of the forecast area early this
morning. The southward movement of the front will end as a weak
ridge temporarily builds over the region. A shortwave trough
will move across the southern half of the area today, just north
of the stalled boundary. This wave may initiate convection as
it rushes eastward. The energy will also flatten the ridge and
pull deeper moisture northward. Latest model data is keeping the
higher probabilities for showers/storms today south of I-70.
One of the key components on how far north the activity could
develop will be a rather broad surface high that will move
across the Great Lakes. This high will try to push drier air
southward, keeping the showers northward movement at bay. Latest
CAM models are keeping the activity south of I-70, with the
stronger storms well south into the Mid-Atlantic region. NBM
probs for measurable rainfall are further north, but the focus
for the higher probs are also south of I-70. Probabilities of
measurable rain north of I-70 are generally 10 to 20%. While to
the south they rise to 40 to 50%.

Highs today will be right near seasonal averages.

&&

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

-Warm front will bring the next risk for showers and storms
 late Tuesday and Tuesday night.
- Ridging over the Great Lakes is expected to reduce
  precipitation chances briefly Wednesday.

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An ejecting trough out of the Rockies, that will eventually
move over the northern Plains, and ridging over Florida, will
reinforce a surge of moisture into the Ohio River Valley Tuesday
under southwest flow. Severe storms have the potential to
develop late Tuesday and Tuesday night under a destabilizing
airmass and effective shear rapidly increasing from 20kts to
50kts. The Storm Prediction Center has noted the severe
potential with issuing a Slight/Marginal Risk for portions on
Day 3. Based on model soundings and hodographs, hail and
damaging winds will likely be the biggest threat.

A break in the activity is possible Wednesday with weak ridging
aloft.

&&

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


- A new disturbance is expect to return showers and
  thunderstorms late Wednesday night into early Thursday
  morning.
- Ensemble models suggest a very wet pattern into the weekend.
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An active weather pattern will remain in place for our region,
with decent daily precipitation chances through the weekend.
Therefore, flooding concerns will need to be monitor in the
long term.

The potential of a period of severe weather Wednesday
night into early Thursday with a passing disturbance will need
to be monitored closely. Organized convection could be
initiated if sufficient moisture advances north into the Ohio
River Valley. Confidence is high that the wind shear will be
available, it is a matter of destabilization that could pose a
problem for severe convection development.

&&

.AVIATION /12Z MONDAY THROUGH FRIDAY/...
-- Changed Discussion --
Any lingering fog should improve by mid-morning with cigs
lifting through the morning amid dry advection, with return to
VFR anticipated by 18z. A crossing shortwave will trigger
additional showers and possibly a thunderstorm mainly south of
I-70 later this afternoon and evening.

Winds remain light through the period.

.Outlook...
An active pattern will keep periods of precipitation and related
restrictions through much of the week.
-- End Changed Discussion --

&&

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

&&

$$

SYNOPSIS...22
NEAR TERM...22/88
SHORT TERM...Hefferan/22
LONG TERM...Hefferan/22
AVIATION...Rackley/88