Severe Thunderstorm Warning 145, NWS Pittsburgh, PA

Area Forecast Discussion
National Weather Service Pittsburgh PA
626 AM EDT Tue Aug 25 2020

.SYNOPSIS...
Warm and humid conditions will continue today with scattered showers
or an isolated thunderstorm, some of which may generate damaging
wind gusts.

&&

.NEAR TERM /THROUGH TONIGHT/...
The predawn update featured the addition of isolated POPs as per the
latest radar trends with developing weak convection under the
crossing shortwave in nw flow aloft.

The next in series is still expected to generate more convection
later this afternoon although high res models differ in placement
and timing.

The area remains under the threat for scattered severe risk with the
primary hazard from damaging wind. Shear and increasing instability
favor multicell to short bowing segments with eventual congeal into
an organized MCS still possible.

Convection will weaken and wane into the late evening and overnight
hours as shortwave ridging suppresses residual showeres and clouds.

&&

.SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/...
Concerning Wednesday and Wednesday night, the forecast area will
remain in northwest flow as the next shortwave trough will begin to
cross the ridge in the Upper Midwest and then southeast into the
Middle Atlantic. Given the Slight Risk introduced by SPC, will
mention a minimal wind damage risk for the region in the HWO.

Once again the main threat will develop into the afternoon with the
stronger convection waning into the evening.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
Flow is expected be remain relatively fast and become more zonal for
the latter half of the week. This will support a series of
progressive shortwave passages with periodic rain chance fueled by
the northern fringe of tropical moisture funneling over the mid
Atlantic region. A stronger cold front/trough passage is indicated
for the weekend to continue the rain chance. Expect seasonable
temperature throughout.

&&

.AVIATION /10Z TUESDAY THROUGH SATURDAY/...
Mainly VFR conditions are expected to continue with exception for
isolated peri-dawn convection under a passing shortwave, and by sct
storms this aftn with the advn of a stronger system.

.Outlook...
VFR conditions will largely prevail through much of this week with
only periodic restrictions due to thunderstorms and morning fog.

&&

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

&&

Hazardous Weather Outlook
National Weather Service Pittsburgh PA
644 AM EDT Tue Aug 25 2020

MDZ001-OHZ039>041-048>050-057>059-068-069-PAZ007>009-013>016-020>023-
029-031-073>076-WVZ001>004-012-021-509>514-261045-
Garrett-Tuscarawas-Carroll-Columbiana-Coshocton-Harrison-
Jefferson OH-Muskingum-Guernsey-Belmont-Noble-Monroe-Mercer-Venango-
Forest-Lawrence-Butler-Clarion-Jefferson PA-Beaver-Allegheny-
Armstrong-Indiana-Washington-Greene-Westmoreland-Westmoreland Ridges-
Fayette-Fayette Ridges-Hancock-Brooke-Ohio-Marshall-Wetzel-Marion-
Monongalia-Ridges of Eastern Monongalia and Northwestern Preston-
Preston-Eastern Preston-Western Tucker-Eastern Tucker-
644 AM EDT Tue Aug 25 2020

This Hazardous Weather Outlook is for western Maryland, east
central Ohio, northwest Pennsylvania, southwest Pennsylvania,
western Pennsylvania, northern West Virginia and the northern
panhandle of West Virginia.

.DAY ONE...Today and tonight.

Scattered severe thunderstorms are possible today. Damaging wind is
the primary hazard, but severe hail is possible.

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

There is a slight risk for severe thunderstorms on Wednesday. The
primary hazard will be damaging wind gusts.

.SPOTTER INFORMATION STATEMENT...

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

Special Weather Statement
National Weather Service Pittsburgh PA
710 AM EDT Tue Aug 25 2020

PAZ021>023-073-251130-
Armstrong-Westmoreland-Allegheny-Indiana-
710 AM EDT Tue Aug 25 2020

...A STRONG THUNDERSTORM CAPABLE OF PRODUCING HAIL WILL AFFECT WEST
CENTRAL INDIANA...EASTERN ALLEGHENY...NORTHWESTERN WESTMORELAND AND
SOUTHWESTERN ARMSTRONG COUNTIES...

At 709 AM EDT, a strong thunderstorm was located over Leechburg, or
near Vandergrift, moving southeast at 20 mph.

Hail up to the size of nickels is possible with this storm.

Locations impacted include...
Vandergrift...                    Apollo...
Plum...                           Murrysville...
New Kensington...                 Lower Burrell...
Harrison Township...              Arnold...
Brackenridge...                   Leechburg...
Freeport...                       North Apollo...

LAT...LON 4056 7977 4072 7965 4062 7931 4038 7949
TIME...MOT...LOC 1109Z 300DEG 18KT 4061 7964

Special Weather Statement
National Weather Service Pittsburgh PA
741 AM EDT Tue Aug 25 2020

PAZ014-021>023-073-074-251230-
Armstrong-Butler-Westmoreland Ridges-Westmoreland-Allegheny-Indiana-
741 AM EDT Tue Aug 25 2020

...A CLUSTER OF THUNDERSTORMS CAPABLE OF PRODUCING HAIL AND GUSTY
WIND WILL AFFECT SOUTHERN INDIANA...SOUTHEASTERN
BUTLER...NORTHEASTERN ALLEGHENY...CENTRAL WESTMORELAND AND SOUTHERN
ARMSTRONG COUNTIES...

At 740 AM EDT, a cluster of thunderstorms was centered near Apollo,
moving southeast at 25 mph.

Wind gusts up to 45 mph and hail up to the size of nickels are
possible with this cluster of storms.

Locations impacted include...
Penn Hills...                     Monroeville...
Greensburg...                     Indiana...
Latrobe...                        Vandergrift...
Homer City...                     Apollo...
Plum...                           Murrysville...
New Kensington...                 Lower Burrell...

This includes  Pennsylvania Turnpike between mile markers 43 and 54.

These storms may intensify, so monitor local radio or television
stations for additional information and possible warnings from the
National Weather Service.

LAT...LON 4055 7993 4076 7972 4076 7953 4059 7890
      4018 7924
TIME...MOT...LOC 1140Z 299DEG 24KT 4056 7955