Alert archive / Iowa / Flash Flood Watches in 2019

Flash Flood Watch 5, NWS Quad Cities, IA

May 21, 201913 counties in Iowa; 9 counties in Illinois; Clark County, Scotland County, Missouri

NWS Quad Cities, IA issued this flash flood watch at May 21, 2019, 3:37 AM CDT for 13 counties in Iowa; 9 counties in Illinois; Clark County, Scotland County, Missouri. It took effect at May 21, 2019, 4:00 AM CDT. It was in force for 19 hr.

The area

The counties it named.

The facts

Issued: May 21, 2019, 3:37 AM CDT (08:37 UTC)
In effect from: May 21, 2019, 4:00 AM CDT
Expired: May 21, 2019, 11:05 PM CDT
In force: 19 hr
Issued by: NWS Quad Cities, IA
Flood severity: None

All 24 counties

Cedar County, IA, Des Moines County, IA, Henry County, IA, Iowa County, IA, Jefferson County, IA, Johnson County, IA, Keokuk County, IA, Lee County, IA, Louisa County, IA, Muscatine County, IA, Scott County, IA, Van Buren County, IA, Washington County, IA, Bureau County, IL, Hancock County, IL, Henderson County, IL, Henry County, IL, McDonough County, IL, Mercer County, IL, Putnam County, IL, Rock Island County, IL, Warren County, IL, Clark County, MO, Scotland County, MO

The radar

The Quad Cities radar (KDVN), 73 km from the middle of the area, began a volume at 08:38 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

Lincoln, IL (KILX), launched 00:00Z, 8.6 hours before the alert went out and 239 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: 1293 m above ground
0-6 km bulk shear: 41 kt
0-1 km storm-relative helicity: 50 m²/s²
0-3 km storm-relative helicity: 120 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 Quad Cities, IA wrote its last area forecast discussion before this flash flood watch went out at May 21, 12:46 AM CDT, 2 hours 51 minutes earlier.

Area forecast discussion, May 21, 12:46 AM CDT, 2 hours 51 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 Quad Cities, IA issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 21, 9:13 AM CDT	River Flood Watch	DVN	Clinton, Scott	35 hr
May 21, 10:06 AM CDT	River Flood Watch	DVN	Lee	24 hr
May 21, 10:00 AM CDT	River Flood Warning	DVN	Hancock, McDonough	12 days
May 21, 8:14 AM CDT	River Flood Warning	DVN	Clark	66 hr

Nearby

Flash Flood Watches in Iowa, 2019 Flash Flood Watches in Illinois, 2019 Flash Flood Watches in Missouri, 2019 Every flash flood watch in 2019

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.