Alert archive / California / Areal Flood Advisories in 2012

Areal Flood Advisory 21, NWS Los Angeles, CA

August 13, 2012Los Angeles County, California

NWS Los Angeles, CA issued this areal flood advisory at Aug 13, 2012, 12:39 PM PDT for Los Angeles County, California. It was in force for 111 min.

The area

The counties it named.

The facts

Issued
Aug 13, 2012, 12:39 PM PDT (19:39 UTC)
Expired
Aug 13, 2012, 2:30 PM PDT
In force
111 min
Issued by
NWS Los Angeles, CA
Area
Storm-based polygon

County Los Angeles County, CA

The radar

The Santa Ana Mts radar (KSOX), 71 km from the middle of the area, began a volume at 19:41 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

San Diego, CA (KNKX), launched 12:00Z, 7.7 hours before the alert went out and 184 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-pSkew-T log-p diagram, San Diego, CA at 12:00Z on 2012-08-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 446 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, San Diego, CA at 12:00Z on 2012-08-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -7 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
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
446 J/kg
Mixed-layer CIN
-661 J/kg
Mixed-layer LCL
1527 m above ground
0-6 km bulk shear
14 kt
0-1 km storm-relative helicity
-7 m²/s²
0-3 km storm-relative helicity
67 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 areal flood advisory went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Los Angeles, CA wrote its last area forecast discussion before this areal flood advisory went out at Aug 13, 11:30 AM PDT, 1 hour 9 minutes earlier.

Area forecast discussion, Aug 13, 11:30 AM PDT, 1 hour 9 minutes before
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Hazardous weather outlook, Aug 13, 6:00 AM PDT, 6 hours 39 minutes before
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  <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.
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The office that day

Everything else NWS Los Angeles, CA issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 12, 9:05 PM PDTSmall Craft AdvisoryLOX6 hr
Aug 12, 9:47 PM PDTExcessive Heat WarningLOXLos Angeles22 hr
Aug 13, 2:36 PM PDTSmall Craft AdvisoryLOX9 days
Aug 13, 2:42 PM PDTAreal Flood AdvisoryLOX108 min
Aug 13, 4:30 PM PDTAreal Flood AdvisoryLOXLos Angeles3 hr

Nearby

Areal Flood Advisories in California, 2012Every areal flood advisory in 2012

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.