Severe Thunderstorm Warning 124, NWS Pittsburgh, PA

Area Forecast Discussion
National Weather Service Pittsburgh PA
324 PM EDT Mon Jun 24 2019

.SYNOPSIS...
Showers and storms will develop late this afternoon and evening
before a cold front crosses the Ohio Valley. Tuesday will be cool and
dry before warm air and humidity return late in the week.

&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
The Ohio Valley remains firmly in the warm sector of a sfc cyclone in
ern WI. The 12Z PBZ RAOB shows abundant moisture and steepening
lapse rates, and a high-altitude freezing level with PWAT unseasonably
high.

A strong trough is noted in the Plains, while an MCV is evident in
satellite imagery near KY. In the wake of a lead shortwave trough
this morning (with attendant warm advection-driven showers), brief
ridging will aid in heating of the very moist warm sector.

There remains some uncertainty if storms will form ahead of a pre-
frontal trough that is expected to advance ewd across the Ohio
Valley this evening. Any storms that do form ahead of the front will
likely become supercellular given the shear/instability profile
anticipated. Any such isolated storms will be capable of all hazards:
damaging wind gusts, hail (although it will take an especially
intense updraft to produce severe hail today, given the freezing
level height), tornadoes, and isolated flash flooding (given the
expected warm rain processes, rain production will be highly
efficient).

The higher-certainty evolution is that storms will form along a pre-
frontal trough as the MCV advances newd, becoming linear mode as the
trough moves into the region early this evening. An organized severe
wind event is anticipated with this line.

In the wake of the cold frontal passage, there is a possibility for
isolated-scattered showers as the cold pool of the H5 wave moves
over and assists in the release of weak low-level potential
instability. These showers should wane by morning, setting Tue up for
a benign, cool day.

&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/...
Drier air will spread into the region on Tue. Upper-level flow will
transition toward zonal Tue-Wed, with any rain chances tied to low-
amplitude waves embedded in the flow. At this time, Tue appears
likely to feature cooler air and no rain.

It does appear one such low-amplitude wave will interact with a
frontal boundary or lake breeze on Wed, with a potential for
scattered showers and storms.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
Rising H5 heights can be expected for the remainder of the week as
the Bermuda High amplifies and builds into the central Appalachians.
This trend suggests daily increases in temperature through the
remainder of the week. The ridge position will be important for
assessing any threat for convection during the late-week timeframe.

&&

.AVIATION /19Z MONDAY THROUGH SATURDAY/...
Showers and thunderstorms will overspread the region late this
afternoon and evening ahead an incoming upper-level trough and sfc
cold front. An MCV will move into the area from the Tennessee Valley
through this evening, which will further enhance storm initiation
while potentially causing sfc winds to back to sely. The storms are
expected to form along a broken to solid line while moving from the
southwest to the northeast. Strong and erratic winds are likely to
occur with any thunderstorm, along with brief reductions in
cig/vsby.

A weak post-frontal inversion will trap boundary-layer moisture and
result in MVFR to IFR cigs overnight. Drier and cooler air moving in
from the southwest will erode this inversion and its moisture,
allowing for quicker improvement to VFR conditions Tuesday morning.

.Outlook...
Mostly VFR conditions are expected the rest of the week, though brief
cat reductions could occur during storms associated with a weak mid-
week disturbance.

&&

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

&&

Kramar

Hazardous Weather Outlook...UPDATED
National Weather Service Pittsburgh PA
345 PM EDT Mon Jun 24 2019

MDZ001-WVZ511>514-251945-
Garrett-Preston-Eastern Preston-Western Tucker-Eastern Tucker-
345 PM EDT Mon Jun 24 2019

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

.DAY ONE...This afternoon and tonight.

Severe thunderstorms are likely this afternoon and evening. Storms
will be capable of damaging wind gusts, and perhaps an isolated
tornado or large hail.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday.

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.

OHZ039>041-048>050-057>059-068-069-PAZ007>009-013>016-020>023-029-
031-073>076-WVZ001>004-012-021-509-510-251945-
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-
345 PM EDT Mon Jun 24 2019

...SEVERE THUNDERSTORM WATCH 440 IN EFFECT UNTIL 10 PM EDT THIS
EVENING...

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

.DAY ONE...This afternoon and tonight.

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

   Severe Thunderstorm Watch.

Storms will be capable of damaging wind gusts, and perhaps an
isolated tornado or large hail.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday.

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.