Severe Thunderstorm Warning 102, NWS Pittsburgh, PA

Area Forecast Discussion
National Weather Service Pittsburgh PA
119 PM EDT Fri Jun 16 2017

.SYNOPSIS...
Scattered showers and thunderstorms are possible again today,
though expected to be less widespread than yesterday. Saturday
will offer a break before more widespread showers and storms
return Sunday.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Between noon and 1pm, a line of showers and thunderstorms has
developed across central portions of the forecast area. Have
added categorical mention of rain along the line. Luckily, so
far the line only has scattered coverage across Allegheny
County, one of the areas that received the heaviest rainfall
over the last three days. Also added heavy rain mention in the
forecast as well.

With noon update, brought slight chance pops farther west
through the afternoon. While there is a bit of a lull in
precipitation across the WV/MD ridges as of noon, the showers
and thunderstorms that have developed over the last hour have
been a bit farther west than expected.

Previous...
Shortwave trough will get hung up over the Mid-
Atlantic region this afternoon, and models are hinting that
storms could re-fire over the southeast and ridges. This is in
response to the aforementioned shortwave and also there will be
an east- southeast flow on the other side of the ridges which
will promote low-level moisture convergence along the higher
elevations. Cloud cover will be a little tricky as drier air is
diving southward behind the exiting trough, but still plenty of
moisture gets hung up on its northern flank. Would expect to see
a clearing line moving southward this morning, but how far
south it makes it is still uncertain. Additionally, with surface
dewpoints still well into the 60s, cu would likely develop in
areas that see sun. High temps will be a couple of degrees
cooler then Thursday.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
Models are now showing a drier Saturday, with temperatures
rising under strong southerly flow. The next shortwave trough is
a little slower on the latest model runs, with most of the large
scale ascent spinning northward over the Great Lakes by late in
the day. Have lowered PoPs on Saturday, but kept a mention in
the ridges, as a southeastern low level flow could produce some
pop-up activity in these locales during the afternoon. If we
can get the sun involved, should see a well mixed atmosphere,
which will lead to very warm temps.

Noticeably deeper trough will dig into the Western Great Lakes
on Sunday, and waves of energy will spin eastward ahead of the
main upper level system. The first wave will cross Sunday
morning, returning the risk for showers. More substantial
activity will develop Sunday afternoon ahead of the slow moving
surface front and a stronger shortwave. Still a good deal of
uncertainty on the timing and strength of convection late
Sunday, so this part of the forecast will be modified over the
next couple of days.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
Showers/thunderstorms should continue into at least Monday
morning, as the surface front gets hung up Sunday night with
the development of a surface low southwest of the area. This
may hold up complete frontal passage until Monday afternoon.

The upper trough is progged to persist across the NE CONUS
through mid week. Temperatures are expected to return to near
seasonal levels.

&&

.AVIATION /17Z FRIDAY THROUGH TUESDAY/...
MVFR stratus will linger into the afternoon at DUJ and MGW, but
otherwise VFR is expected at the rest of sites with developing
cu. Low level moisture convergence and instability will allow
for showers and storms to refire across southeastern portions of
the region today. While this has not been added to ANY taf site
yet, amendments may be needed based on hi res guidance and
mesoanalysis.

Expect some fog again overnight with plenty of moisture in the
low levels from recent rainfall.

.Outlook...
Occasional restrictions are expected through the weekend with
some morning fog and afternoon showers/thunderstorms.

&&

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

&&

Hazardous Weather Outlook...UPDATED
National Weather Service Pittsburgh PA
427 AM EDT Fri Jun 16 2017

MDZ001-OHZ039>041-048>050-057>059-068-069-PAZ007>009-013>016-020>023-
029-031-073>076-WVZ001>004-012-021-509>514-170830-
Garrett-Tuscarawas-Carroll-Columbiana-Coshocton-Harrison-Jefferson-
Muskingum-Guernsey-Belmont-Noble-Monroe-Mercer-Venango-Forest-
Lawrence-Butler-Clarion-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-
427 AM EDT Fri Jun 16 2017

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

.DAY ONE...Today and Tonight.

No hazardous weather is expected at this time.

.DAYS TWO THROUGH SEVEN...Saturday through Thursday.

Widespread showers and storms are possible again Sunday and Sunday
night. This could potentially bring more heavy rain and increase the
threat of flooding.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE PITTSBURGH PA
1025 AM EDT FRI JUN 16 2017

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

0346 PM     TSTM WND DMG     1 W MCCANDLESS TOWNSHIP 40.58N  80.04W
06/15/2017                   ALLEGHENY          PA   DEPT OF HIGHWAYS

            TWO UPROOTED TREES AND SIX TREES SHEARED OFF 3/4 OF THE
            WAY UP

&&

EVENT NUMBER PBZ1701602

98