Alert archive / Pennsylvania / Flash Flood Warnings in 2011

Flash Flood Warning 21, NWS Pittsburgh, PA

August 19, 2011Beaver County, Lawrence County, Pennsylvania; Columbiana County, Ohio

NWS Pittsburgh, PA issued this flash flood warning at Aug 19, 2011, 5:33 PM EDT for Beaver County, Lawrence County, Pennsylvania; Columbiana County, Ohio. It was in force for 3 hr. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: Aug 19, 2011, 5:33 PM EDT (21:33 UTC)
Expired: Aug 19, 2011, 8:30 PM EDT
In force: 3 hr
Issued by: NWS Pittsburgh, PA
Area: Storm-based polygon
Flood severity: None

Counties Columbiana County, OH, Beaver County, PA, Lawrence County, PA

The radar

The Pittsburgh radar (KPBZ), 39 km from the middle of the area, began a volume at 21:36 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, 9.6 hours before the alert went out and 55 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: 840 J/kg
Mixed-layer CIN: -43 J/kg
Mixed-layer LCL: 1229 m above ground
0-6 km bulk shear: 25 kt
0-1 km storm-relative helicity: 36 m²/s²
0-3 km storm-relative helicity: 60 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this flash flood warning 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 flash flood warning went out at Aug 19, 4:57 PM EDT, 36 minutes earlier.

Area forecast discussion, Aug 19, 4:57 PM EDT, 36 minutes before

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

Hazardous weather outlook, Aug 19, 4:58 PM EDT, 35 minutes before

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

In the hours before

Local storm report, Aug 19, 5:10 PM EDT, 23 minutes before

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

Local storm report, Aug 19, 5:15 PM EDT, 18 minutes before

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

Local storm report, Aug 19, 5:18 PM EDT, 15 minutes before

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

Special weather statement, Aug 19, 5:27 PM EDT, 6 minutes before

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

Special weather statement, Aug 19, 5:30 PM EDT, 3 minutes before

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

Local storm report, Aug 19, 5:31 PM EDT, 2 minutes before

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 18, 10:35 PM EDT	Special Weather Statement	PBZ	Venango	40 min
Aug 19, 7:37 AM EDT	Special Weather Statement	PBZ	Lawrence	38 min
Aug 19, 7:54 AM EDT	Severe Thunderstorm Warning	PBZ	Beaver, Butler, Lawrence	38 min
Aug 19, 8:10 AM EDT	Special Weather Statement	PBZ	Forest, Venango	50 min
Aug 19, 8:44 AM EDT	Special Weather Statement	PBZ	Clarion	46 min
Aug 19, 8:50 AM EDT	Special Weather Statement	PBZ	Beaver	40 min
Aug 19, 9:22 AM EDT	Severe Thunderstorm Warning	PBZ	Clarion, Jefferson	53 min
Aug 19, 9:30 AM EDT	Special Weather Statement	PBZ	Allegheny	60 min
Aug 19, 10:07 AM EDT	Special Weather Statement	PBZ	Indiana	53 min
Aug 19, 10:16 AM EDT	Special Weather Statement	PBZ	Fayette	59 min
Aug 19, 10:33 AM EDT	Severe Thunderstorm Warning	PBZ	Allegheny, Fayette, Washington, Westmoreland	57 min
Aug 19, 1:00 PM EDT	Special Weather Statement	PBZ	Mercer	45 min
Aug 19, 1:10 PM EDT	Special Weather Statement	PBZ	Beaver	35 min
Aug 19, 1:27 PM EDT	Severe Thunderstorm Warning	PBZ	Butler, Lawrence, Mercer, Venango	63 min
Aug 19, 1:47 PM EDT	Special Weather Statement	PBZ	Beaver	28 min
Aug 19, 1:50 PM EDT	Special Weather Statement	PBZ	Lawrence	55 min
Aug 19, 2:38 PM EDT	Flash Flood Warning	PBZ	Lawrence	60 min
Aug 19, 2:44 PM EDT	Special Weather Statement	PBZ	Butler	31 min
Aug 19, 2:54 PM EDT	Special Weather Statement	PBZ	Allegheny, Beaver	36 min
Aug 19, 2:58 PM EDT	Severe Thunderstorm Warning	PBZ	Butler, Lawrence, Mercer, Venango	53 min
Aug 19, 3:05 PM EDT	Special Weather Statement	PBZ	Forest	55 min
Aug 19, 3:19 PM EDT	Severe Thunderstorm Warning	PBZ	Allegheny, Beaver, Washington	56 min
Aug 19, 3:24 PM EDT	Areal Flood Warning	PBZ	Lawrence, Mercer	3 hr
Aug 19, 3:24 PM EDT	Severe Thunderstorm Warning	PBZ	Allegheny, Beaver, Butler	66 min
Aug 19, 3:54 PM EDT	Special Weather Statement	PBZ	Lawrence	36 min
Aug 19, 3:56 PM EDT	Severe Thunderstorm Warning	PBZ	Allegheny, Fayette, Westmoreland	64 min
Aug 19, 4:00 PM EDT	Special Weather Statement	PBZ	Beaver	30 min
Aug 19, 4:03 PM EDT	Areal Flood Warning	PBZ	Beaver	3 hr
Aug 19, 4:03 PM EDT	Special Weather Statement	PBZ	Allegheny	27 min
Aug 19, 4:19 PM EDT	Severe Thunderstorm Warning	PBZ	Allegheny, Washington	36 min
Aug 19, 4:24 PM EDT	Flash Flood Warning	PBZ	Allegheny	3 hr
Aug 19, 4:27 PM EDT	Severe Thunderstorm Warning	PBZ	Beaver, Lawrence	63 min
Aug 19, 4:31 PM EDT	Special Weather Statement	PBZ	Lawrence	29 min
Aug 19, 4:48 PM EDT	Severe Thunderstorm Warning	PBZ	Allegheny, Fayette, Washington, Westmoreland	57 min
Aug 19, 4:52 PM EDT	Flash Flood Watch	PBZ	Allegheny, Beaver, Fayette, Lawrence, Washington, Westmoreland	3 hr
Aug 19, 4:53 PM EDT	Special Weather Statement	PBZ	Armstrong	37 min
Aug 19, 4:58 PM EDT	Areal Flood Warning	PBZ	Beaver, Lawrence	3 hr
Aug 19, 5:00 PM EDT	Special Weather Statement	PBZ	Armstrong	60 min
Aug 19, 5:04 PM EDT	Special Weather Statement	PBZ	Westmoreland	26 min
Aug 19, 5:27 PM EDT	Special Weather Statement	PBZ	Fayette	33 min
Aug 19, 5:55 PM EDT	Special Weather Statement	PBZ	Venango	35 min
Aug 19, 6:49 PM EDT	Special Weather Statement	PBZ	Forest	56 min
Aug 19, 6:54 AM EDT	Special Weather Statement	PBZ	Columbiana	66 min
Aug 19, 1:12 PM EDT	Special Weather Statement	PBZ	Jefferson	48 min
Aug 19, 1:42 PM EDT	Special Weather Statement	PBZ	Carroll	63 min
Aug 19, 2:02 PM EDT	Special Weather Statement	PBZ	Muskingum	28 min
Aug 19, 2:07 PM EDT	Severe Thunderstorm Warning	PBZ	Coshocton, Muskingum	53 min
Aug 19, 2:26 PM EDT	Special Weather Statement	PBZ	Carroll	34 min
Aug 19, 2:31 PM EDT	Special Weather Statement	PBZ	Jefferson	29 min
Aug 19, 2:42 PM EDT	Special Weather Statement	PBZ	Harrison	33 min
Aug 19, 3:16 PM EDT	Special Weather Statement	PBZ	Tuscarawas	29 min
Aug 19, 3:42 PM EDT	Special Weather Statement	PBZ	Guernsey	33 min
Aug 19, 4:37 PM EDT	Special Weather Statement	PBZ	Belmont	38 min
Aug 19, 4:51 PM EDT	Special Weather Statement	PBZ	Columbiana	24 min
Aug 19, 3:08 PM EDT	Special Weather Statement	PBZ	Brooke	67 min
Aug 19, 3:13 PM EDT	Special Weather Statement	PBZ	Hancock	32 min
Aug 19, 4:36 PM EDT	Special Weather Statement	PBZ	Ohio	54 min
Aug 19, 5:30 PM EDT	Special Weather Statement	PBZ	Wetzel	30 min
Aug 19, 6:09 PM EDT	Special Weather Statement	PBZ	Preston	36 min
Aug 19, 7:54 PM EDT	Special Weather Statement	PBZ	Tucker	36 min

Nearby

Flash Flood Warnings in Pennsylvania, 2011 Flash Flood Warnings in Ohio, 2011 Every flash flood warning in 2011

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.