418
FXUS61 KPBZ 021314
AFDPBZ

Area Forecast Discussion
National Weather Service Pittsburgh PA
914 AM EDT Tue Jul 2 2024

.SYNOPSIS...
Another dry day with lots of sun and warm temperatures. Shower
and thunderstorm chance will return late Wednesday and remain
through the end of the week.

&&

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

- Dry and warmer today.

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500mb ridge axis will move over the region this afternoon.
Surface high will drift over the New England area and warm air
advection will be present throughout the day. This setup will
allow for dry weather, plenty of sunshine, and warmer
temperatures. Humidity levels will remain low, as the juicy air
sits well to the southwest.

&&

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

- Dry weather through most of Wednesday.
- Temperatures continue to warm on Wednesday.
- Showers and thunderstorms possible Wednesday night and
  Thursday.

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The ridge will slowly break down on Wednesday, as a shortwave
trough digs into the upper Midwest and pulls a surface cold
front eastward. NBM begins to introduce probabilities for
measurable precipitation Wednesday evening. The high probs
(30-40%) are mainly over Ohio and NW PA at this time, expanding
south and eastward overnight. Based on the current timing,
models are keeping the bulk of the instability over Western and
Central Ohio, though some instability (<500j/kg) is present in
our eastern Ohio counties. Shear should be sufficient for storms
as well, though the timing of the front and some lingering warm
air aloft may cap things until late. At this time, SPC has a
portion of the region in a marginal risk. The primary concern
would be wind at this point, though a secondary concern is heavy
downpours as PWAT values will be increasing.

The cold front will continue to track southeastward Wednesday
night and Thursday and may stall south of PIT late Thursday
morning. At the same time, the upper ridge will be flattening
across the upper Ohio Valley, creating a zonal flow aloft.
Shortwaves passing through this the zonal flow will support
multiple rounds of showers and storms along the east-west
oriented boundary in a moisture-rich environment. At this time,
the placement of the boundary is generally south of I-70 but
there is some uncertainty in it`s exact placement. That being
said, the very moist airmass that will be present across at
least a portion of the region (NBM has a 60-80% chance of PWATs
nearing climatological max of 2 inches for the areas from I-70
south) could lead to training of thunderstorms and flooding rain
potential.

Thursday looks to be warm and very humid.

&&

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

- Risk for showers and thunderstorms continue through the end of
  the work week with the return of a more active pattern.

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Ensembles are showing an upper wave diving through the Great
Lakes to close out the week, though uncertainty comes into play
with how deep the trough is and subsequently how strong the
surface low is and where it tracks. Consensus is to our north
and dragging a cold front through sometime early in the weekend,
but details remain fuzzy.

&&

.AVIATION /13Z TUESDAY THROUGH SATURDAY/...
VFR AND RELATIVELY LIGHT WIND will prevail through the TAF
period as high pressure tracks across the Upper Ohio Valley.

.Outlook...
VFR is expected through Wednesday. A slow moving front is
expected to persist across the region Wednesday night through
Friday, bringing showers, thunderstorms and associated
restrictions back to the area through the end of the week. A
cold front will maintain showers, thunderstorms and ocnl
restrictions on Saturday.

&&

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

&&

$$

SYNOPSIS...22
NEAR TERM...22
SHORT TERM...22/34
LONG TERM...Cermak/22/34
AVIATION...88