Alert archive / Arkansas / Flash Flood Watches in 2011

Flash Flood Watch 4, NWS Little Rock, AR

April 30, 201131 counties in Arkansas

NWS Little Rock, AR issued this flash flood watch at Apr 30, 2011, 4:10 AM CDT for 31 counties in Arkansas. It took effect at Apr 30, 2011, 7:00 PM CDT. It was in force for 57 hr.

The area

The counties it named.

The facts

Issued: Apr 30, 2011, 4:10 AM CDT (09:10 UTC)
In effect from: Apr 30, 2011, 7:00 PM CDT
Expired: May 3, 2011, 3:40 AM CDT
In force: 57 hr
Issued by: NWS Little Rock, AR
Flood severity: None

All 31 counties

Arkansas County, AR, Baxter County, AR, Calhoun County, AR, Clark County, AR, Cleburne County, AR, Cleveland County, AR, Conway County, AR, Dallas County, AR, Faulkner County, AR, Fulton County, AR, Garland County, AR, Grant County, AR, Hot Spring County, AR, Independence County, AR, Izard County, AR, Jackson County, AR, Jefferson County, AR, Lincoln County, AR, Lonoke County, AR, Marion County, AR, Monroe County, AR, Ouachita County, AR, Perry County, AR, Pike County, AR, Prairie County, AR, Pulaski County, AR, Saline County, AR, Sharp County, AR, Stone County, AR, White County, AR, Woodruff County, AR

The radar

The Little Rock radar (KLZK), 10 km from the middle of the area, began a volume at 09:12 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

Springfield, MO (KSGF), launched 00:00Z, 9.2 hours before the alert went out and 263 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 2599 m above ground
0-6 km bulk shear: 54 kt
0-1 km storm-relative helicity: 118 m²/s²
0-3 km storm-relative helicity: 518 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 watch went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Little Rock, AR wrote its last area forecast discussion before this flash flood watch went out at Apr 30, 12:26 AM CDT, 3 hours 44 minutes earlier.

Area forecast discussion, Apr 30, 12:26 AM CDT, 3 hours 44 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, Apr 29, 5:00 AM CDT, 23 hours 10 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 Little Rock, AR issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Apr 30, 8:16 AM CDT	River Flood Advisory	LZK	Lawrence, Randolph	36 hr
Apr 30, 8:31 AM CDT	River Flood Advisory	LZK	Saline	36 hr
Apr 30, 8:36 AM CDT	Lake Wind Advisory	LZK	Arkansas, Baxter, Bradley, Calhoun, Clark, Cleburne and 28 more	6 hr
Apr 30, 6:32 PM CDT	Special Weather Statement	LZK	Independence	28 min
Apr 30, 6:36 PM CDT	Severe Thunderstorm Warning	LZK	Independence, Sharp	24 min
Apr 30, 6:39 PM CDT	Severe Thunderstorm Warning	LZK	Conway, Faulkner, Perry, Pope, Yell	51 min
Apr 30, 6:50 PM CDT	Severe Thunderstorm Warning	LZK	Garland, Montgomery, Perry, Saline, Yell	31 min

Nearby

Flash Flood Watches in Arkansas, 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.