087
FXUS61 KPBZ 041352 AAA
AFDPBZ

Area Forecast Discussion...UPDATED
National Weather Service Pittsburgh PA
952 AM EDT Fri Apr 4 2025

.SYNOPSIS...
An active pattern continues through the weekend with multiple
rounds of showers and thunderstorms. Severe storms will be
possible Saturday.

&&

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

- Flood Watch remains in effect for portions of the region.
- Showers continue overnight.
- Break from the widespread rain until later this afternoon.
-------------------------------------------------------------------

Due to the 1.5 to 3 inches of rainfall in the last 48 hours
across the southern half of the forecast area and several more
rounds of rainfall expected through Sunday, a Flood Watch
remains in effect. The axis of rainfall and stalled front have
shifted farther south this morning as broad high pressure drifts
across the Great Lakes region. This will largely suppress rain
over our area through much of the daytime hours. Still, flooding
continues in locations south of Pittsburgh this morning with a
number of road closures and river/stream rises. Flood Warnings
are ongoing for much of that area.

Flooding is expected to gradually subside through the morning
and early afternoon without additional rainfall. Upper level
height rises are expected this afternoon as a large upper low
digs south of the four corners region and a large 500mb high
moves over the southeastern US. The ridging will push the
surface high to the northeast and allow the stalled front to
begin to slowly move northward from the Mid-Atlantic region as
evening approaches. This will allow showers and thunderstorms to
lift northwards later this afternoon and into the overnight.

The lower cloud deck is expected to shift southwards with the
rain today, and the northern edge of this can already be seen on
satellite crossing central Ohio. This should allow for some
partial sunshine this afternoon generally north of I-70. Areas
that do see some sun will see temperatures quickly climb, while
areas under cloud cover struggle to warm. High temperatures
should generally run around seasonal averages, but areas farther
north may see a boost from increased insolation.

&&

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

- Rounds of showers and thunderstorms continue into the weekend.
- A Flood Watch remains in effect for portions of eastern Ohio.
- Severe weather is possible Saturday.
- A cold front on Sunday will finally bring an end to the heavy
  rainfall threat.
-------------------------------------------------------------------

Another surface low is expected to track NE out of the
Mississippi Valley region tonight, pushing the front back north
this time as a warm front. Showers and thunderstorms once again
increase in coverage as the front and surface low move across
the Upper Ohio Valley region into early Saturday. However, if
the front moves far enough north, we may see a break in the
activity late tonight and Saturday morning as the main moisture
plume will be forced northward and the area will be well into
the warm sector.

A second round of thunderstorms is then expected Saturday
afternoon/evening ahead of a crossing cold front. CAMs are
hinting at severe weather potential with this round of possibly
discrete storms, and modeled hodographs suggest at least
marginal tornado threat.

Showers and thunderstorms will continue into Saturday night as
low pressure crosses, but the stalled front remains. Flooding
potential will increase on Saturday with repeated rounds of
heavy rainfall on an already saturated ground. Rises are
expected on area rivers.

Ensemble clusters agree on rapid height falls Sunday. This will
finally shunt the surface ridge, that had been firmly planted
over the southeast CONUS coast, and allow a cold front to
advance through the area and off to the south late Sunday,
bringing an end to the heavy rain and storm potential.

&&

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


- Colder next week with lighter rain/snow chances each day.
-------------------------------------------------------------------

Weak surface low pressure, crossing out of the Great Lakes will
aid in strong northwesterly flow behind the front Monday into
Tuesday. This could bring a additional few showers to the region
on Tuesday.

Upper troughing is expected to persist through midweek,
resulting in below normal temperatures and daily rain/snow
chances, albeit not nearly as intense as what we`re experiencing
this week.

&&

.AVIATION /14Z FRIDAY THROUGH TUESDAY/...
For the rest of the day today, a return of mostly dry and VFR
conditions is favored for most. The only chances of MVFR linger
around 50% for ZZV and MGW closer to the stalled front. During
Friday afternoon, expect the chance for rain to return to the
region as the front surges north again. The marginal chance for
thunderstorms increase during the evening with low elevated
instability, which will also bring the increased probability for
the return of MVFR for a majority of ports. No mentions were
maintained for now with probabilities below 30%. Restrictions
are expected to linger through Saturday with more chances of
rain, though chances of MVFR remain highest for ZZV, FKL, and
DUJ at roughly 70%.

Outlook... The Upper Ohio River Valley will remain positioned
between a Mountain West trough and East Coast ridge that will foster
multiple rounds of moderate to locally heavy rain through Sunday.
Timing and shape in each shortwave remains variable, which may alter
the axis of highest precipitation rates and areas of greatest
restrictions. Aviation customers should anticipate limited windows
of VFR and dry conditions through the period as the pattern favors
MVFR/IFR restrictions, heavier rain showers and occasional
thunderstorms.

A deepening upper level trough is likely to overtake the region
Monday, shifting towards a colder pattern featuring periodic
rain/snow chances and continued ceiling restrictions. By mid-week,
the trough is expected to move out of the region as a ridge builds
in. This will likely result in reduced restrictions.

&&

.HYDROLOGY...
The potential for heavy rainfall will exist through Sunday. At
this time, areas across Ohio have the potential to see the
heaviest rainfall, where a Flood Watch continues. Current NBM
values indicate a 70 percent chance or greater of at least 2
inches of rain over a 72 hr period in this region. Lesser
probabilities exist further east, though a trend up has been
noted in the latest ensemble guidance and will need to be
monitored for any potential expansion of the flood watch. The
exact location of the heaviest rain will depend on the position
of a quasi-stationary surface front. Precipitable water is
expected to remain elevated through Sunday, with some periodic
jet enhanced ascent. Even after the heavy rain potential ends,
river levels will likely remain elevated for a few days. Current
ensemble river forecast projections also focus the most
significant river rises across Ohio.

Will monitor further trends for any future adjustments to the
watch.

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
PA...Flood Watch through Sunday morning for PAZ021-029-031-073>076.
OH...Flood Watch through Sunday morning for OHZ039-040-048>050-
     057>059-068-069.
WV...Flood Watch through Sunday morning for WVZ001>004-012-021-509-
     510.

&&

$$

SYNOPSIS...Rackley/22
NEAR TERM...Rackley/22
SHORT TERM...Rackley/22
LONG TERM...Rackley
AVIATION...Milcarek/Lupo
HYDROLOGY...