Severe Thunderstorm Warning 22, NWS Pittsburgh, PA

Area Forecast Discussion
National Weather Service Pittsburgh PA
732 PM EDT Tue Apr 2 2024

.SYNOPSIS...
Strong low pressure moving into the Great Lakes and Ohio River
valley will bring severe thunderstorms with heavy rainfall to
the area tonight. Cooler weather with continued rain and snow
showers will persist into Friday as the deep and cold low
pressure moves slowly across the upper Ohio Valley.

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
KEY MESSAGES:

- Tornado watch in effect through 2AM

- Severe threat increases by this evening especially west of
  PIT

- The peak period for severe storms is from 6pm to 11pm tonight

- Renewed heavy rains tonight will continue flooding threat

- Expanded the flood watch to most of area until 8am EDT
  Wednesday

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7:30PM update... Tornado watch has been issued for eastern OH
into western PA and northern WV through 2AM. Expect arrival of
storms to our eastern OH area around 8PM spreading further east
over the next few hours with all hazards including damaging
wind, large hail, and tornadoes possible. The eastward extent
will be shunted into western PA by the placement of a warm front
currently stuck over Allegheny County, with instability
confined to its west...

Surface low over IL will continue to deepen as it tracks to
Lake Michigan tonight and stalls. Strong low level warm
advection on nose of 55 knot 850 mb jet will surge northeast
from the lower Ohio Valley into the Upper Ohio Valley this
evening. Temperatures have recovered some in wake of morning
precipitation and a well defined boundary now cuts through the
central portion of the forecast area with temperatures in the
lower 70s south of Pittsburgh with dew points near 60F. To the
north, there are easterly winds and temperatures in the 50s.

Extremely deep and low 500 mb heights of 5200 to 5250 meters
with massive area of large height falls to about 250 meters
occurs with this system, certainly rare for April.

The significant threat will arrive this evening as upstream
storms form in IN/KY and western OH and move rapidly northeast.
The low level boundary could certainly play a role in that
evolution and especially in regard to heavy rain threat and
severe threat.

Supercell and tornado indices this evening become favorable over
the Ohio portion of the forecast area but some of the severe
weather will make it into the remainder of the area late this
evening.

Latest CAMs have continued to be aggressive in producing heavy
rainfall tonight especially in Indiana to Clarion and Jefferson
Counties. Have extended the flood watch until 8am Wednesday to
account for prolonged precipitation beyond the severe threat
overnight.

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY/...
KEY MESSAGES:

- deep closed low with very cold temps aloft keeps showery
  weather across the area with potential for snow

- accumulations of 3 to 5 inches in eastern Tucker County and
  light accumulations especially above 2,000 feet elsewhere

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520 mb closed low expected to move across northern Indiana
Wednesday and then Ohio into Pennsylvania Thursday. Cold
advection especially aloft is impressive on Wednesday with 700
mb temperatures falling to -10C by Wednesday afternoon with -30C
at 500 mb. -32C 500 mb cold pocket then crosses Ohio and West
Virginia on Thursday.

Needless to say, rather vigorous convection will develop
especially during the afternoons with strong April Sun. Graupel
and hail will be possible each afternoon especially Wednesday over
Ohio. Although precipitation could mix with or change to snow in
the lower elevations, most accumulations will be confined to
elevations above 2,000 feet and generally only at night.

&&

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

- Building heights will gradually allow warming and drying
  conditions

- Weekend should be dry

- Sky cover forecast on Monday will be challenging

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

Main upper low pulls away toward New England Thursday night with
large height rises over the forecast area. However, another
trough axis rotates south across the forecast area Friday
keeping chances for showers going despite drying trend.

Saturday and Sunday appear to be dry with moderating
temperatures as heights rise ahead of a narrow upper ridge
between exiting upper low and new upper low moving into the
central Plains.

Obviously Monday sky cover forecast will be of extreme interest
across a large portion of the area. The trend of having upper
ridging overhead has been decreasing with a moist southwest flow
across the area ahead of Plains trough. Obviously still a week
away, but current trends are certainly more cloudy.

&&

.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
The forecast period will begin before the next round of showers
and storms moves through the region. Most ports will begin with
VFR conditions, with the exception of FKL/DUJ/ZZV. FKL/DUJ are
expected to remain in LIFR/IFR cigs through almost the entire
forecast period. These ports will also see MVFR vis with showers
into Wednesday afternoon. A period of storms is possible late
this evening and into the overnight hours. ZZV will begin the
forecast period with MVFR restrictions with low clouds and rain.
Thunderstorms are anticipated at ZZV during the evening hours as
well.

Area of thunderstorms will move eastward into the overnight
hours. All remaining ports will eventually deteriorate to high
LIFR/low MVFR as the evening progresses. All ports are expected
to see restrictive showers into Wednesday morning, with a period
of thunderstorms during the evening, early overnight hours.

LLWS is expected at most ports this evening and into the
overnight hours as a strong low-level jet crosses the region.
Eventually, these winds will mix down to the surface so
increasing surface winds, with gusts of 20 to 25 mph are
anticipated late tonight and through much of Wednesday.

Improvement is possible at all ports Wednesday afternoon.

.Outlook... Restrictions, gusty winds, and rain and snow
showers are likely Thursday and Friday, under an upper low. VFR
returns Sat under high pressure.

&&

.HYDROLOGY...
Overnight rainfall and expected rainfall tonight has resulted in
large increases in expected crests of the mainstem rivers.
Some upgrades to river flood warnings have already been
necessary, and a river flood watch has been issued for all of
the upper Ohio River forecast points. Currently expecting crests
of minor to moderate flood as a result.

Some of the tributaries that aren't already near bankfull are
expected to rise with additional heavy rains tonight.

Although we are expecting flooding on Ohio, the Allegheny and
Monongahela will rise several feet into action stage and minor
flooding is not currently expected. However, rainfall in
Allegheny Basin will need to be closely monitored as recent
trends suggest higher rainfall totals are possible.

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
PA...Flood Watch through Wednesday morning for PAZ013>016-020>022-
     029-031-073>078.
OH...Flood Watch through Wednesday morning for OHZ039>041-048>050-
     057>059-068-069.
WV...Flood Watch through Wednesday morning for WVZ001>004-012-021-
     509>514.

&&

SYNOPSIS...Craven
NEAR TERM...Craven/MLB
SHORT TERM...Craven
LONG TERM...Craven
AVIATION...22
HYDROLOGY...

Hazardous Weather Outlook...UPDATED
National Weather Service Pittsburgh PA
822 PM EDT Tue Apr 2 2024

PAZ007>009-040030-
Mercer-Venango-Forest-
822 PM EDT Tue Apr 2 2024

This Hazardous Weather Outlook is for northwest Pennsylvania.

.DAY ONE...Tonight.

A severe weather risk increases tonight with large hail, damaging
wind gusts and locally heavy rainfall expected.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday.

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

Weather spotters are encouraged to report significant weather
conditions according to Standard Operating Procedures.

PAZ013>016-022-073>078-WVZ511>513-040030-
Lawrence-Butler-Clarion-Jefferson PA-Armstrong-Westmoreland-
Higher Elevations of Westmoreland-Fayette-
Higher Elevations of Fayette-Indiana-Higher Elevations of Indiana-
Preston-Eastern Preston-Western Tucker-
822 PM EDT Tue Apr 2 2024

...FLOOD WATCH NOW IN EFFECT THROUGH WEDNESDAY MORNING...

This Hazardous Weather Outlook is for western Pennsylvania and
northern West Virginia.

.DAY ONE...Tonight.

Please listen to NOAA Weather Radio or go to weather.gov on the
Internet for more information about the following hazards.

   Flood Watch.

A severe weather risk increases tonight. Tornadoes, large hail, and
damaging wind gusts are expected. Locally heavy rainfall and flash
flooding are also expected. Mainstem river flooding is also
expected.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday.

Please listen to NOAA Weather Radio or go to weather.gov on the
Internet for more information about the following hazards.

   Flood Watch.

.SPOTTER INFORMATION STATEMENT...

Weather spotters are encouraged to report significant weather
conditions according to Standard Operating Procedures.

OHZ039>041-048>050-057>059-068-069-PAZ020-021-029-031-WVZ001>004-012-
021-509-510-040030-
Tuscarawas-Carroll-Columbiana-Coshocton-Harrison-Jefferson OH-
Muskingum-Guernsey-Belmont-Noble-Monroe-Beaver-Allegheny-Washington-
Greene-Hancock-Brooke-Ohio-Marshall-Wetzel-Marion-Monongalia-
Ridges of Eastern Monongalia and Northwestern Preston-
822 PM EDT Tue Apr 2 2024

...FLOOD WATCH NOW IN EFFECT THROUGH WEDNESDAY MORNING...
...TORNADO WATCH 81 IN EFFECT UNTIL 2 AM EDT WEDNESDAY...

This Hazardous Weather Outlook is for east central Ohio, southwest
Pennsylvania, western Pennsylvania, and northern West Virginia.

.DAY ONE...Tonight.

Please listen to NOAA Weather Radio or go to weather.gov on the
Internet for more information about the following hazards.

   Flood Watch.
   Tornado Watch.

A severe weather risk increases tonight. Tornadoes, large hail, and
damaging wind gusts are expected. Locally heavy rainfall and flash
flooding are also expected. Mainstem river flooding is also
expected.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday.

Please listen to NOAA Weather Radio or go to weather.gov on the
Internet for more information about the following hazards.

   Flood Watch.

.SPOTTER INFORMATION STATEMENT...

Weather spotters are encouraged to report significant weather
conditions according to Standard Operating Procedures.

WVZ514-040030-
Eastern Tucker-
822 PM EDT Tue Apr 2 2024

...FLOOD WATCH NOW IN EFFECT THROUGH WEDNESDAY MORNING...

This Hazardous Weather Outlook is for northern West Virginia.

.DAY ONE...Tonight.

Please listen to NOAA Weather Radio or go to weather.gov on the
Internet for more information about the following hazards.

   Flood Watch.

A severe weather risk increases tonight. Tornadoes, large hail, and
damaging wind gusts are expected. Locally heavy rainfall and flash
flooding are also expected.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday.

Please listen to NOAA Weather Radio or go to weather.gov on the
Internet for more information about the following hazards.

   Flood Watch.

Snow showers are expected Wednesday night through Friday morning
with total accumulations of 3 to 5 inches. Accumulations are most
likely during the nighttime hours.

.SPOTTER INFORMATION STATEMENT...

Weather spotters are encouraged to report significant weather
conditions according to Standard Operating Procedures.

WM

Preliminary Local Storm Report
National Weather Service Pittsburgh PA
645 PM EDT Tue Apr 02 2024

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1000 AM     Flood            2 WNW Ross Township     40.54N  80.05W
04/02/2024                   Allegheny          PA   Dept of Highways

            Reis Run Rd closed due to flooding along Lowries Run
            and Harts Run

1000 AM     Flood            4 SSW St. Clairsville   40.02N  80.94W
04/02/2024                   Belmont            OH   Dept of Highways

            SR9 closed due to flooding along Neffs Run and McMahon
            Creek

1200 PM     Flood            4 WSW Zelienople        40.76N  80.22W
04/02/2024                   Beaver             PA   Dept of Highways

            Brush Creek Rd closed due to flooding along Brush
            Creek. Road remains closed at 6pm as water is high

1200 PM     Flash Flood      1 S Blawnox             40.47N  79.86W
04/02/2024                   Allegheny          PA   Dept of Highways

            Verona Rd closed due to flooding of Sandy Creek

0130 PM     Flash Flood      1 N Tarentum            40.62N  79.76W
04/02/2024                   Allegheny          PA   Dept of Highways

            Bull Creek Rd closed due to flooding along Bull Creek
            between Metz Rd and Ridge Rd

&&

Event Number PBZ2402093
Event Number PBZ2402094
Event Number PBZ2402095
Event Number PBZ2402096
Event Number PBZ2402097

Kramar

Preliminary Local Storm Report
National Weather Service Pittsburgh PA
717 PM EDT Tue Apr 02 2024

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1200 PM     Flood            5 ENE New Martinsville  39.68N  80.78W
04/02/2024                   Wetzel             WV   Dept of Highways

            Proctor Creek Rd flooded along Proctor Creek. Water
            remained over the road at 630 pm

&&

Event Number PBZ2402098

Kramar