Alert archive / Pennsylvania / Flash Flood Watches in 2011

Flash Flood Watch 8, NWS Pittsburgh, PA

September 5, 20114 counties in Pennsylvania; Marion County, Wetzel County, West Virginia

NWS Pittsburgh, PA issued this flash flood watch at Sep 5, 2011, 3:49 PM EDT for 4 counties in Pennsylvania; Marion County, Wetzel County, West Virginia. It took effect at Sep 6, 2011, 6:00 AM EDT. It was in force for 22 hr.

The area

The counties it named.

The facts

Issued: Sep 5, 2011, 3:49 PM EDT (19:49 UTC)
In effect from: Sep 6, 2011, 6:00 AM EDT
Expired: Sep 7, 2011, 4:05 AM EDT
In force: 22 hr
Issued by: NWS Pittsburgh, PA
Flood severity: None

Counties Fayette County, PA, Greene County, PA, Jefferson County, PA, Westmoreland County, PA, Marion County, WV, Wetzel County, WV

The radar

The Pittsburgh radar (KPBZ), 61 km from the middle of the area, began a volume at 19:53 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

Washington/Dulle, VA (KIAD), launched 12:00Z, 7.8 hours before the alert went out and 245 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: 248 J/kg
Mixed-layer CIN: -63 J/kg
Mixed-layer LCL: 614 m above ground
0-6 km bulk shear: 40 kt
0-1 km storm-relative helicity: 15 m²/s²
0-3 km storm-relative helicity: 67 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.5

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this flash flood watch 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 watch went out at Sep 5, 1:02 PM EDT, 2 hours 47 minutes earlier.

Area forecast discussion, Sep 5, 1:02 PM EDT, 2 hours 47 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, Sep 5, 4:24 AM EDT, 11 hours 25 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
Sep 4, 8:52 PM EDT	Special Weather Statement	PBZ	Marion, Monongalia, Preston	53 min

Nearby

Flash Flood Watches in Pennsylvania, 2011 Flash Flood Watches in West Virginia, 2011 Every flash flood watch 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.