Alert archive / Iowa / Flash Flood Watches in 2010

Flash Flood Watch 9, NWS Sioux Falls, SD

August 1, 20107 counties in South Dakota; 8 counties in Iowa

NWS Sioux Falls, SD issued this flash flood watch at Aug 1, 2010, 9:30 PM CDT for 7 counties in South Dakota; 8 counties in Iowa. It took effect at Aug 2, 2010, 4:00 AM CDT. It was in force for 8 hr.

The area

The counties it named.

The facts

Issued
Aug 1, 2010, 9:30 PM CDT (02:30 UTC)
In effect from
Aug 2, 2010, 4:00 AM CDT
Expired
Aug 2, 2010, 11:36 AM CDT
In force
8 hr
Issued by
NWS Sioux Falls, SD
Flood severity
None

Counties Buena Vista County, IA, Cherokee County, IA, Clay County, IA, Ida County, IA, O'Brien County, IA, Plymouth County, IA, Sioux County, IA, Woodbury County, IA, Bon Homme County, SD, Clay County, SD, Hutchinson County, SD, Lincoln County, SD, Turner County, SD, Union County, SD, Yankton County, SD

The radar

The Sioux Falls radar (KFSD), 78 km from the middle of the area, began a volume at 02:30 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

Minneapolis, MN (KMPX), launched 00:00Z, 2.5 hours before the alert went out and 310 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, Minneapolis, MN at 00:00Z on 2010-08-02Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1046 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, Minneapolis, MN at 00:00Z on 2010-08-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 75 square meters per square second.19395878Sfc1 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
1046 J/kg
Mixed-layer CIN
-9 J/kg
Mixed-layer LCL
1149 m above ground
0-6 km bulk shear
28 kt
0-1 km storm-relative helicity
75 m²/s²
0-3 km storm-relative helicity
256 m²/s²
Significant tornado parameter
0.2
Supercell composite
2.1

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 Sioux Falls, SD wrote its last area forecast discussion before this flash flood watch went out at Aug 1, 2:56 PM CDT, 6 hours 34 minutes earlier.

Area forecast discussion, Aug 1, 2:56 PM CDT, 6 hours 34 minutes before
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Hazardous weather outlook, Aug 1, 11:09 AM CDT, 10 hours 21 minutes before
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<html lang="en">
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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 Sioux Falls, SD issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 1, 8:21 PM CDTSevere Thunderstorm WarningFSDBeadle39 min
Aug 1, 10:43 PM CDTAreal Flood WarningFSDJerauld, Sanborn30 hr
Aug 2, 6:35 AM CDTFlash Flood WarningFSDLincoln, Minnehaha, Turner3 hr
Aug 2, 6:47 AM CDTFlash Flood WarningFSDBon Homme, Charles Mix, Douglas, Hutchinson3 hr
Aug 2, 7:03 AM CDTFlash Flood WarningFSDNobles, Rock3 hr

Nearby

Flash Flood Watches in Iowa, 2010Flash Flood Watches in South Dakota, 2010Every flash flood watch in 2010

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.