Alert archive / Pennsylvania / Special Weather Statements in 2021

Special Weather Statement, NWS Pittsburgh, PA

June 30, 2021Allegheny County, Pennsylvania

NWS Pittsburgh, PA issued this special weather statement at Jun 30, 2021, 12:56 PM EDT for Allegheny County, Pennsylvania. It was in force for 34 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Jun 30, 2021, 12:56 PM EDT (16:56 UTC)
Expired: Jun 30, 2021, 1:30 PM EDT
In force: 34 min
Issued by: NWS Pittsburgh, PA

County Allegheny County, PA

The radar

The Pittsburgh radar (KPBZ), 19 km from the middle of the area, began a volume at 17:00 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Pittsburgh, PA (KPIT), launched 12:00Z, 4.9 hours before the alert went out and 10 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 807 J/kg
Mixed-layer CIN: -49 J/kg
Mixed-layer LCL: 1240 m above ground
0-6 km bulk shear: 32 kt
0-1 km storm-relative helicity: 71 m²/s²
0-3 km storm-relative helicity: 66 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 1.2

Open this sounding in Storm Lab

The text

As transmitted.

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What forecasters said that day

The local office's own words before this special weather statement went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Pittsburgh, PA wrote its last area forecast discussion before this special weather statement went out at Jun 30, 9:24 AM EDT, 3 hours 32 minutes earlier.

Area forecast discussion, Jun 30, 9:24 AM EDT, 3 hours 32 minutes before

Area Forecast Discussion
National Weather Service Pittsburgh PA
924 AM EDT Wed Jun 30 2021

.SYNOPSIS...
Warm and humid conditions will give way to showers and storms
this afternoon. Cooler weather is expected over the weekend.

&&

.NEAR TERM /THROUGH TONIGHT/...
Conditions today started with convection along the lake boundary to
the north with showers and thunderstorms tracking across I-80. This
convection has decreased as of 13Z with just a few showers left over.
Some remnant outflows were noticeable as of 12Z on radar. this area
just south of I-80 will serve as a focal point for redevelopment
after noon with a timing of 17Z to 18Z. The morning 12Z PIT sounding
indicates an MU CAPE of 1400 J/Kg with nearly 1000 J/Kg of DCAPE. A
subtle warm layer and cap at 700MB will hinder development a bit. A
approach of the front will likely overcome this this with MU CAPE
bubbling to around 3000 J/Kg. This will likely depend on how fast the
front slides south. With this concern, wind gusts and flooding will
be the main concerns.

Nevertheless, have added pops through the afternoon period and into
the overnight as the front will keep convection going into the early
morning hours. Slightly slow storm motions, PWATs in the 1.6 to 1.7
range, and the potential of training due to the orientation of the
front, the threat of flooding is a concern. Will discuss the
potential for a Flash Flood Watch.

&&

.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
Occasional showers and storms will continue Thursday and Friday as a
cold front crosses Thursday and the aforementioned upper trough
continues to deepen and pivots over the forecast area. Cooler
temperatures are forecast through the period with CAA behind the
front. Forecast values were heavily weighted on direct model output
and are lower than MOS and blends which would incorporate a warm bias
due to recent weather.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
Shower chances and cooler temperature continue Saturday with the
upper low over the forecast area...followed by drier conditions and
near normal temperatures on INdependence Day as high pressure builds
in from the west.

&&

.AVIATION /14Z WEDNESDAY THROUGH SUNDAY/...
High pressure will maintain VFR until a pre-frontal shortwave prompts
widespread shower and thunderstorm development this
afternoon/evening. TEMPO TSRA are included for most ports this in
anticipation. Gusty winds, lightning, and hail are possible with
these thunderstorms.

MVFR/IFR cigs and vis are expected early tomorrow
morning under cold advection.

.Outlook...
Occasional restrictions are expected through Friday as a troughing
pattern results in periodic moist convection.

&&

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

&&

Hazardous weather outlook, Jun 30, 12:56 PM EDT, 0 minutes before

Hazardous Weather Outlook
National Weather Service Pittsburgh PA
1256 PM EDT Wed Jun 30 2021

WVZ511>514-011700-
Preston-Eastern Preston-Western Tucker-Eastern Tucker-
1256 PM EDT Wed Jun 30 2021

This Hazardous Weather Outlook is for northern West Virginia.

.DAY ONE...This afternoon and tonight.

Strong thunderstorms will be possible this afternoon and evening.
Gusty winds will be the main threat. Localized flooding will also be
possible.

.DAYS TWO THROUGH SEVEN...Thursday through Tuesday.

Excessive rainfall may lead to instances of flooding Thursday and
Thursday night.

.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>004-012-021-509-510-011700-
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-
Higher Elevations of Westmoreland-Fayette-
Higher Elevations of Fayette-Hancock-Brooke-Ohio-Marshall-Wetzel-
Marion-Monongalia-
Ridges of Eastern Monongalia and Northwestern Preston-
1256 PM EDT Wed Jun 30 2021

...SEVERE THUNDERSTORM WATCH 326 IN EFFECT UNTIL 8 PM EDT THIS
EVENING...

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

.DAYS TWO THROUGH SEVEN...Thursday through Tuesday.

Excessive rainfall may lead to instances of flooding Thursday and
Thursday night.

.SPOTTER INFORMATION STATEMENT...

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

In the hours before

Special weather statement, Jun 30, 11:57 AM EDT, 59 minutes before

Special Weather Statement
National Weather Service Pittsburgh PA
1157 AM EDT Wed Jun 30 2021

OHZ048-057-301630-
Coshocton-Muskingum-
1157 AM EDT Wed Jun 30 2021

...AN AREA OF STRONG THUNDERSTORMS CAPABLE OF PRODUCING GUSTY WIND
WILL AFFECT SOUTHWESTERN COSHOCTON AND MUSKINGUM COUNTIES...

At 1157 AM EDT, strong thunderstorms were clustered near Hanover, or
10 miles east of Newark, moving east at 30 mph.

Wind gusts up to 45 mph are possible with this storm.

Locations impacted include...
Zanesville...                     South Zanesville...
North Zanesville...               Dresden...
Frazeysburg...                    Philo...
Warsaw...                         Pleasant Grove...
Conesville...                     Fultonham...
Nellie...                         Chandlersville...

This includes Interstate 70 in Ohio between mile markers 145 and 165.

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

LAT...LON 3993 8223 3993 8220 4021 8218 4021 8219
      4024 8218 4024 8220 4031 8219 4038 8202
      4015 8184 3988 8180 3982 8210 3982 8216
      3991 8216 3991 8223
TIME...MOT...LOC 1557Z 251DEG 25KT 4012 8224

Special weather statement, Jun 30, 12:40 PM EDT, 16 minutes before

Special Weather Statement
National Weather Service Pittsburgh PA
1240 PM EDT Wed Jun 30 2021

OHZ050-059-PAZ021-029-WVZ002>004-301730-
Jefferson-Belmont-Washington-Allegheny-Marshall-Brooke-Ohio-
1240 PM EDT Wed Jun 30 2021

...AN AREA OF STRONG THUNDERSTORMS CAPABLE OF PRODUCING GUSTY WIND
AND HEAVY RAIN WILL AFFECT SOUTHEASTERN JEFFERSON...NORTHEASTERN
BELMONT...NORTHWESTERN WASHINGTON...SOUTHWESTERN ALLEGHENY...OHIO...
MARSHALL AND BROOKE COUNTIES...

At 1240 PM EDT, strong thunderstorms were clustered over Warwood,
moving east at 10 mph.

Wind gusts up to 55 mph are possible with this storm.

Locations impacted include...
Mount Lebanon...                  Bethel Park...
Wheeling...                       McMurray...
Washington...                     Canonsburg...
Martins Ferry...                  Warwood...
Wellsburg...                      Bethlehem...
West Liberty...                   Triadelphia...

This includes the following highways...
  Interstate 70 in West Virginia between mile markers 0 and 14.
  Interstate 70 in Pennsylvania between mile markers 0 and 19.
  Interstate 79 in Pennsylvania between mile markers 37 and 60.
  Interstate 376 in Pennsylvania between mile markers 58 and 65.

Torrential rainfall also is occurring with this storm and may cause
localized flooding. Do not drive your vehicle through flooded
roadways.

Frequent cloud to ground lightning is occurring with this storm. Seek
safe shelter inside a building or vehicle.

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

LAT...LON 4001 8071 4020 8081 4048 8016 4039 8004
      4028 8002 4013 8031
TIME...MOT...LOC 1640Z 262DEG 11KT 4012 8071

Special weather statement, Jun 30, 12:56 PM EDT, 0 minutes before

Special Weather Statement
National Weather Service Pittsburgh PA
1256 PM EDT Wed Jun 30 2021

PAZ020-021-073-301730-
Westmoreland-Beaver-Allegheny-
1256 PM EDT Wed Jun 30 2021

...AN AREA OF STRONG THUNDERSTORMS CAPABLE OF PRODUCING GUSTY WIND
AND HEAVY RAIN WILL AFFECT SOUTH CENTRAL BEAVER...ALLEGHENY AND
NORTHWESTERN WESTMORELAND COUNTIES...

At 1256 PM EDT, strong thunderstorms were clustered over Pittsburgh,
moving northeast at 40 mph.

Wind gusts up to 45 mph are possible with this storm.

Locations impacted include...
Pittsburgh...                     Penn Hills...
Mount Lebanon...                  Bethel Park...
Ross Township...                  McCandless Township...
Monroeville...                    Moon Township...
McKeesport...                     Franklin Park...
Shaler Township...                Plum...

This includes the following highways...
  Pennsylvania Turnpike between mile markers 37 and 60.
  Interstate 79 in Pennsylvania between mile markers 59 and 73.
  Interstate 376 in Pennsylvania between mile markers 49 and 58, and
  between mile markers 63 and 84.

Torrential rainfall also is occurring with this storm and may cause
localized flooding. Do not drive your vehicle through flooded
roadways.

Frequent cloud to ground lightning is occurring with this storm. Seek
safe shelter inside a building or vehicle.

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

LAT...LON 4028 8002 4047 8015 4042 8029 4052 8037
      4067 7986 4067 7976 4044 7959
TIME...MOT...LOC 1656Z 244DEG 35KT 4045 7996

The office that day

Everything else NWS Pittsburgh, PA issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jun 29, 8:02 PM EDT	Areal Flood Advisory	PBZ	Mercer, Venango	118 min
Jun 30, 12:40 PM EDT	Special Weather Statement	PBZ	Washington	50 min
Jun 30, 1:04 PM EDT	Severe Thunderstorm Warning	PBZ	Washington	26 min
Jun 30, 1:06 PM EDT	Severe Thunderstorm Warning	PBZ	Allegheny, Washington, Westmoreland	24 min
Jun 30, 1:19 PM EDT	Areal Flood Advisory	PBZ	Allegheny, Washington, Westmoreland	3 hr
Jun 30, 1:23 PM EDT	Severe Thunderstorm Warning	PBZ	Allegheny, Washington, Westmoreland	52 min
Jun 30, 1:29 PM EDT	Special Weather Statement	PBZ	Washington	31 min
Jun 30, 1:52 PM EDT	Special Weather Statement	PBZ	Indiana	23 min
Jun 30, 2:03 PM EDT	Severe Thunderstorm Warning	PBZ	Indiana, Westmoreland	42 min
Jun 30, 2:12 PM EDT	Flash Flood Warning	PBZ	Allegheny, Beaver, Washington, Westmoreland	3 hr
Jun 30, 2:14 PM EDT	Flash Flood Warning	PBZ	Allegheny, Washington	2 hr
Jun 30, 2:26 PM EDT	Severe Thunderstorm Warning	PBZ	Washington	49 min
Jun 30, 2:37 PM EDT	Severe Thunderstorm Warning	PBZ	Indiana	38 min
Jun 30, 2:41 PM EDT	Severe Thunderstorm Warning	PBZ	Allegheny, Beaver, Washington	34 min
Jun 30, 2:45 PM EDT	Severe Thunderstorm Warning	PBZ	Indiana, Westmoreland	45 min
Jun 30, 3:03 PM EDT	Special Weather Statement	PBZ	Armstrong	27 min
Jun 30, 3:13 PM EDT	Special Weather Statement	PBZ	Greene	32 min
Jun 30, 3:29 PM EDT	Special Weather Statement	PBZ	Fayette	31 min
Jun 30, 3:32 PM EDT	Areal Flood Advisory	PBZ	Armstrong, Indiana	3 hr
Jun 30, 3:35 PM EDT	Special Weather Statement	PBZ	Forest	25 min
Jun 30, 3:52 PM EDT	Special Weather Statement	PBZ	Fayette	23 min
Jun 30, 3:55 PM EDT	Special Weather Statement	PBZ	Jefferson	35 min
Jun 30, 4:29 PM EDT	Special Weather Statement	PBZ	Butler	31 min
Jun 30, 5:05 PM EDT	Special Weather Statement	PBZ	Mercer	25 min
Jun 30, 5:11 PM EDT	Special Weather Statement	PBZ	Lawrence	34 min
Jun 30, 5:58 PM EDT	Severe Thunderstorm Warning	PBZ	Allegheny, Beaver, Butler, Washington	47 min
Jun 30, 6:44 PM EDT	Special Weather Statement	PBZ	Allegheny	46 min
Jun 30, 1:56 PM EDT	Severe Thunderstorm Warning	PBZ	Brooke, Marshall, Ohio	34 min
Jun 30, 3:04 PM EDT	Special Weather Statement	PBZ	Hancock	26 min
Jun 30, 4:14 PM EDT	Special Weather Statement	PBZ	Monongalia, Preston	31 min
Jun 30, 5:26 PM EDT	Special Weather Statement	PBZ	Hancock	34 min
Jun 30, 11:57 AM EDT	Special Weather Statement	PBZ	Muskingum	33 min
Jun 30, 12:20 PM EDT	Severe Thunderstorm Warning	PBZ	Guernsey, Muskingum	25 min
Jun 30, 12:37 PM EDT	Severe Thunderstorm Warning	PBZ	Coshocton, Guernsey, Muskingum, Noble, Tuscarawas	23 min
Jun 30, 12:54 PM EDT	Severe Thunderstorm Warning	PBZ	Coshocton, Guernsey, Muskingum, Tuscarawas	51 min
Jun 30, 1:21 PM EDT	Severe Thunderstorm Warning	PBZ	Belmont, Guernsey, Harrison, Monroe, Noble, Tuscarawas	24 min
Jun 30, 1:38 PM EDT	Severe Thunderstorm Warning	PBZ	Belmont, Guernsey, Harrison, Monroe, Noble, Tuscarawas	52 min
Jun 30, 4:52 PM EDT	Special Weather Statement	PBZ	Carroll, Columbiana	23 min

Nearby

Special Weather Statements in Pennsylvania, 2021 Every special weather statement in 2021

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.