Alert archive / Iowa / Flash Flood Watches in 2020

Flash Flood Watch 2, NWS Quad Cities, IA

May 28, 202014 counties in Iowa; Scotland County, Missouri

NWS Quad Cities, IA issued this flash flood watch at May 28, 2020, 3:32 AM CDT for 14 counties in Iowa; Scotland County, Missouri. It took effect at May 28, 2020, 7:00 AM CDT. It was in force for 12 hr.

The area

The counties it named.

The facts

Issued
May 28, 2020, 3:32 AM CDT (08:32 UTC)
In effect from
May 28, 2020, 7:00 AM CDT
Expired
May 28, 2020, 7:00 PM CDT
In force
12 hr
Issued by
NWS Quad Cities, IA
Flood severity
None

Counties Benton County, IA, Buchanan County, IA, Cedar County, IA, Delaware County, IA, Dubuque County, IA, Henry County, IA, Iowa County, IA, Jefferson County, IA, Johnson County, IA, Jones County, IA, Keokuk County, IA, Linn County, IA, Van Buren County, IA, Washington County, IA, Scotland County, MO

The radar

The Quad Cities radar (KDVN), 91 km from the middle of the area, began a volume at 08:34 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

Davenport, (KDVN), launched 00:00Z, 8.5 hours before the alert went out and 98 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, Davenport, at 00:00Z on 2020-05-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 172 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, Davenport, at 00:00Z on 2020-05-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 15 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
172 J/kg
Mixed-layer CIN
-4 J/kg
Mixed-layer LCL
1393 m above ground
0-6 km bulk shear
13 kt
0-1 km storm-relative helicity
15 m²/s²
0-3 km storm-relative helicity
30 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 28, 12:39 AM CDT, 2 hours 53 minutes earlier.

Area forecast discussion, May 28, 12:39 AM CDT, 2 hours 53 minutes before
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Hazardous weather outlook, May 27, 4:11 AM CDT, 23 hours 21 minutes before
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  <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.
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The office that day

Everything else NWS Quad Cities, IA issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 27, 8:46 PM CDTSpecial Weather StatementDVNJones29 min
May 27, 8:56 PM CDTSpecial Weather StatementDVNDubuque49 min
May 28, 9:22 AM CDTFlash Flood WarningDVNBuchanan, Delaware6 hr
May 28, 2:37 PM CDTRiver Flood WatchDVNClinton, Scott42 hr
May 28, 3:10 PM CDTFlash Flood WarningDVNClinton, Jackson5 hr
May 27, 7:45 PM CDTSpecial Weather StatementDVNWhiteside30 min
May 28, 3:34 PM CDTSpecial Weather StatementDVNWhiteside86 min
May 28, 4:18 PM CDTFlash Flood WarningDVNCarroll, Whiteside4 hr
May 28, 4:25 PM CDTSpecial Weather StatementDVNBureau, Putnam65 min
May 28, 4:36 PM CDTSpecial Weather StatementDVNBureau, Putnam54 min

Nearby

Flash Flood Watches in Iowa, 2020Flash Flood Watches in Missouri, 2020Every flash flood watch in 2020

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.