Alert archive / Pennsylvania / Special Weather Statements in 2021

Special Weather Statement, NWS Pittsburgh, PA

August 10, 2021Allegheny County, Pennsylvania

NWS Pittsburgh, PA issued this special weather statement at Aug 10, 2021, 1:27 PM EDT for Allegheny County, Pennsylvania. It was in force for 33 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: Aug 10, 2021, 1:27 PM EDT (17:27 UTC)
Expired: Aug 10, 2021, 2:00 PM EDT
In force: 33 min
Issued by: NWS Pittsburgh, PA
Hail: 0.00 in
Wind: 40

County Allegheny County, PA

The radar

The Pittsburgh radar (KPBZ), 28 km from the middle of the area, began a volume at 17:30 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, 5.5 hours before the alert went out and 16 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: 521 J/kg
Mixed-layer CIN: -57 J/kg
Mixed-layer LCL: 727 m above ground
0-6 km bulk shear: 19 kt
0-1 km storm-relative helicity: 170 m²/s²
0-3 km storm-relative helicity: 155 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.8

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 Aug 10, 8:52 AM EDT, 4 hours 35 minutes earlier.

Area forecast discussion, Aug 10, 8:52 AM EDT, 4 hours 35 minutes before

Area Forecast Discussion
National Weather Service Pittsburgh PA
852 AM EDT Tue Aug 10 2021

.SYNOPSIS...
Seasonable warmth, humidity, and periodic showers and thunderstorms
can be expected until cold frontal passage late this week.

&&

.NEAR TERM /THROUGH TONIGHT/...
The mid mrng update featured POP adjustments based on radar and the
latest high res mdl solns as sct to nmrs shwrs and tstms can be
expected today. Upr support/ascent is increasing with the
encroachment of a Great Lakes-to-mid OH valley shortwave trough.
Warm mid lvls with -6 C at 500 mb, and a lack of effective shear are
precluding severe dvlpmnt. Expect lcl downpours with that activity.

Isolated strong storms may develop this aftn with a damaging gust
severe threat supported by steep llvl lapse rate and by mid lvl dry
air encroachment and resulting evaporative cooling/downburst
formation. Passage of the shortwave trough/building shortwave ridge
should alleviate coverage of this covection by eve.

&&

.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...
A similar scenario is indicated for Wednesday with the emergence of
another shortwave from the base of broad troughing over the Upr
Midwest, and the approach of that trough/frontal system is likely to
spawn more showers and storms on Thursday.

Temperature for the short term wl be above average with the support
of warm, moist advection. Thursday is borderline approaching Heat
Advisory headlines as Heat Index values are currently forecasted to
be in the upper-90s in portions of our region. However, the
confidence is not too high on this scenario since we still have
precip chances in the forecast.

&&

.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
An eastward sliding cold front will maintain rain chance into
Saturday, but that frontal passage will moderate temperature back to
climatological norms for the weekend.

Showers may return to the region starting Monday as high pressure
breaks down and warm, moist air returns from the south.

&&

.AVIATION /13Z TUESDAY THROUGH SATURDAY/...
Scattered morning shra with isolated ts will shift east in
conjunction with a passing shortwave. A period of MVFR cigs may
develop north of KPIT due to moist advection and the passing showers,
but will be alleviated by diurnal mixing.

Redevelopment of scattered shra/tstms is likely this afternoon as
another shortwave passes to the north. KFKL/KDUJ will be among the
most likely impacted terminals as well as KZZV, where a decaying weak
MCS should help spawn new aftn convection over eastern OH.

Brief ridging and loss of heating should diminish convective activity
tonight before the next shortwave increases precipitation and
MVFR/IFR cig chances Wednesday morning.

.Outlook...
Periodic restrictions in showers/tstms are likely thru Sat with a
series of crossing disturbances.

&&

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

&&

Hazardous weather outlook, Aug 10, 6:33 AM EDT, 6 hours 54 minutes before

Hazardous Weather Outlook
National Weather Service Pittsburgh PA
633 AM EDT Tue Aug 10 2021

OHZ039>041-048>050-057>059-068-069-PAZ007>009-013>016-020>023-029-
031-073>076-WVZ001>004-012-021-509>514-111045-
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-Preston-
Eastern Preston-Western Tucker-Eastern Tucker-
633 AM EDT Tue Aug 10 2021

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

.DAY ONE...Today and tonight.

Isolated incidents of severe wind gusts are possible with afternoon
thunderstorms.

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

Isolated incidents of severe wind gusts are possible Wednesday and
Thursdays as thunderstorms become likely with cold front
encroachment.

.SPOTTER INFORMATION STATEMENT...

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

In the hours before

Special weather statement, Aug 10, 12:42 PM EDT, 45 minutes before

Special Weather Statement
National Weather Service Pittsburgh PA
1242 PM EDT Tue Aug 10 2021

OHZ039-040-049-101715-
Tuscarawas OH-Harrison OH-Carroll OH-
1242 PM EDT Tue Aug 10 2021

...A strong thunderstorm will impact portions of central Harrison,
south central Carroll and southeastern Tuscarawas Counties through
115 PM EDT...

At 1241 PM EDT, Doppler radar was tracking a strong thunderstorm near
Uhrichsville, moving east at 25 mph.

HAZARD...Wind gusts up to 50 mph.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects.

Locations impacted include...
Uhrichsville, Cadiz, Dennison, Scio, Jewett, Bowerston, Tippecanoe,
Stillwater, Deersville, Clendening Lake, Kilgore, and Tappan Lake.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

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

&&

LAT...LON 4024 8142 4040 8139 4047 8099 4023 8097
TIME...MOT...LOC 1641Z 265DEG 21KT 4035 8136

MAX HAIL SIZE...0.00 IN
MAX WIND GUST...50 MPH

Local storm report, Aug 10, 12:54 PM EDT, 33 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE PITTSBURGH PA
1254 PM EDT TUE AUG 10 2021

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

1145 AM     TSTM WND DMG     MINERAL CITY            40.60N  81.36W
08/10/2021                   TUSCARAWAS         OH   911 CALL CENTER

            MULTIPLE TREES REPORTED DOWNED AROUND THE COMMUNITY.

&&

EVENT NUMBER PBZ2102068

FLH

Special weather statement, Aug 10, 12:55 PM EDT, 32 minutes before

Special Weather Statement
National Weather Service Pittsburgh PA
1255 PM EDT Tue Aug 10 2021

PAZ014-101730-
Butler PA-
1255 PM EDT Tue Aug 10 2021

...A strong thunderstorm will impact portions of central Butler
County through 130 PM EDT...

At 1255 PM EDT, radar was tracking a strong thunderstorm near
Zelienople, or 11 miles west of Butler, moving east at 15 mph.

HAZARD...Wind gusts up to 50 mph.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects.

Locations impacted include...
Butler, Homeacre-Lyndora, Shanor-Northvue, Meridian, Meadowood, Oak
Hills, Nixon, Prospect, Harmony, East Butler, Connoquenessing, and
Portersville.

This includes Interstate 79 in Pennsylvania between mile markers 89
and 98.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 4096 7980 4073 7983 4082 8016 4094 8016
TIME...MOT...LOC 1655Z 277DEG 15KT 4087 8011

MAX HAIL SIZE...0.00 IN
MAX WIND GUST...50 MPH

Local storm report, Aug 10, 1:02 PM EDT, 25 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE PITTSBURGH PA
102 PM EDT TUE AUG 10 2021

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

1212 PM     TSTM WND DMG     DELLROY                 40.56N  81.20W
08/10/2021                   CARROLL            OH   911 CALL CENTER

            NUMEROUS TREES AND POWER LINES REPORTED DOWN AROUND
            TOWN.

&&

EVENT NUMBER PBZ2102069

FLH

Local storm report, Aug 10, 1:03 PM EDT, 24 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE PITTSBURGH PA
103 PM EDT TUE AUG 10 2021

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

1215 PM     TSTM WND DMG     2 NE CARROLLTON         40.60N  81.07W
08/10/2021                   CARROLL            OH   911 CALL CENTER

            NUMEROUS TREES AND POWER LINES DOWN THROUGHOUT
            WASWHINGTON TOWNSHIP.

&&

EVENT NUMBER PBZ2102070

FLH

Special weather statement, Aug 10, 1:27 PM EDT, 0 minutes before

Special Weather Statement
National Weather Service Pittsburgh PA
127 PM EDT Tue Aug 10 2021

PAZ021-029-101800-
Washington PA-Allegheny PA-
127 PM EDT Tue Aug 10 2021

...Showers and thunderstorms with gusty wind will impact portions of
central Washington and Allegheny Counties through 200 PM EDT...

At 126 PM EDT, radar indicated showers and thunderstorms along a
line extending from Sewickley to near Cecil-Bishop. Movement was
east at 30 mph.

HAZARD...Wind gusts up to 40 mph.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects.

Locations impacted include...
Pittsburgh, Penn Hills, Mount Lebanon, Bethel Park, Ross Township,
McCandless Township, Monroeville, Moon Township, McMurray,
McKeesport, Franklin Park, and Canonsburg.

This includes the following highways...
  Pennsylvania Turnpike between mile markers 37 and 55.
  Interstate 79 in Pennsylvania between mile markers 42 and 74.
  Interstate 376 in Pennsylvania between mile markers 49 and 84.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 4061 7972 4060 7976 4058 7977 4055 7977
      4054 7973 4021 7982 4020 7986 4018 7985
      4016 7986 4016 7991 4013 7989 4025 8035
      4054 8028 4061 8018 4061 8015 4062 8014
      4063 7971
TIME...MOT...LOC 1726Z 278DEG 25KT 4055 8019 4032 8025

MAX HAIL SIZE...0.00 IN
MAX WIND GUST...40 MPH

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 9, 8:22 PM EDT	Special Weather Statement	PBZ	Lawrence	38 min
Aug 10, 12:39 PM EDT	Special Weather Statement	PBZ	Beaver	36 min
Aug 10, 12:55 PM EDT	Special Weather Statement	PBZ	Butler	35 min
Aug 10, 1:57 PM EDT	Severe Thunderstorm Warning	PBZ	Washington	48 min
Aug 10, 2:03 PM EDT	Severe Thunderstorm Warning	PBZ	Allegheny, Fayette, Washington, Westmoreland	42 min
Aug 10, 2:07 PM EDT	Severe Thunderstorm Warning	PBZ	Armstrong, Butler, Clarion	30 min
Aug 10, 2:25 PM EDT	Special Weather Statement	PBZ	Armstrong	50 min
Aug 10, 2:51 PM EDT	Special Weather Statement	PBZ	Fayette, Greene, Westmoreland	39 min
Aug 10, 2:52 PM EDT	Severe Thunderstorm Warning	PBZ	Greene	33 min
Aug 10, 3:03 PM EDT	Special Weather Statement	PBZ	Indiana	42 min
Aug 10, 2:47 PM EDT	Severe Thunderstorm Warning	PBZ	Marshall, Wetzel	43 min
Aug 10, 3:18 PM EDT	Special Weather Statement	PBZ	Wetzel	27 min
Aug 10, 3:52 PM EDT	Special Weather Statement	PBZ	Marion, Monongalia, Preston, Wetzel	38 min
Aug 10, 3:57 PM EDT	Severe Thunderstorm Warning	PBZ	Marion, Monongalia, Wetzel	13 min
Aug 10, 4:17 PM EDT	Severe Thunderstorm Warning	PBZ	Wetzel	13 min
Aug 10, 4:26 PM EDT	Severe Thunderstorm Warning	PBZ	Wetzel	16 min
Aug 10, 9:16 AM EDT	Special Weather Statement	PBZ	Coshocton	29 min
Aug 10, 11:05 AM EDT	Severe Thunderstorm Warning	PBZ	Tuscarawas	25 min
Aug 10, 11:07 AM EDT	Severe Thunderstorm Warning	PBZ	Coshocton	23 min
Aug 10, 11:28 AM EDT	Severe Thunderstorm Warning	PBZ	Carroll, Tuscarawas	32 min
Aug 10, 11:30 AM EDT	Severe Thunderstorm Warning	PBZ	Coshocton, Tuscarawas	30 min
Aug 10, 12:00 PM EDT	Severe Thunderstorm Warning	PBZ	Carroll, Columbiana, Coshocton, Harrison, Jefferson, Tuscarawas	45 min
Aug 10, 12:07 PM EDT	Special Weather Statement	PBZ	Guernsey, Harrison, Muskingum, Noble	53 min
Aug 10, 12:42 PM EDT	Special Weather Statement	PBZ	Harrison	33 min
Aug 10, 12:59 PM EDT	Severe Thunderstorm Warning	PBZ	Belmont, Guernsey, Harrison, Tuscarawas	46 min
Aug 10, 1:44 PM EDT	Severe Thunderstorm Warning	PBZ	Belmont, Guernsey, Monroe, Noble	31 min
Aug 10, 2:12 PM EDT	Severe Thunderstorm Warning	PBZ	Belmont, Guernsey, Monroe, Noble	48 min
Aug 10, 3:31 PM EDT	Special Weather Statement	PBZ	Monroe	29 min
Aug 10, 4:01 PM EDT	Special Weather Statement	PBZ	Monroe	29 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.