Alert archive / South Carolina / Areal Flood Advisories in 2021

Areal Flood Advisory 72, NWS Charleston, SC

July 28, 2021Charleston County, Colleton County, Dorchester County, South Carolina

NWS Charleston, SC issued this areal flood advisory at Jul 28, 2021, 8:30 AM EDT for Charleston County, Colleton County, Dorchester County, South Carolina. It was in force for 60 min.

The area

The counties it named.

The facts

Issued: Jul 28, 2021, 8:30 AM EDT (12:30 UTC)
Expired: Jul 28, 2021, 9:30 AM EDT
In force: 60 min
Issued by: NWS Charleston, SC
Area: Storm-based polygon

Counties Charleston County, SC, Colleton County, SC, Dorchester County, SC

The radar

The Charleston,SC radar (KCLX), 71 km from the middle of the area, began a volume at 12:29 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

Jacksonville, FL (KJAX), launched 12:00Z, 0.5 hours before the alert went out and 296 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: 737 J/kg
Mixed-layer CIN: -74 J/kg
Mixed-layer LCL: 915 m above ground
0-6 km bulk shear: 15 kt
0-1 km storm-relative helicity: -25 m²/s²
0-3 km storm-relative helicity: -18 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 Charleston, SC wrote its last area forecast discussion before this areal flood advisory went out at Jul 28, 7:00 AM EDT, 1 hour 30 minutes earlier.

Area forecast discussion, Jul 28, 7:00 AM EDT, 1 hour 30 minutes before

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Hazardous weather outlook, Jul 28, 3:25 AM EDT, 5 hours 5 minutes before

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<body>
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    <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>
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        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
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        Please try again in a few minutes.
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The office that day

Everything else NWS Charleston, SC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 28, 12:46 AM EDT	Special Weather Statement	CHS	Jasper	29 min
Jul 28, 7:04 AM EDT	Areal Flood Advisory	CHS	Beaufort, Colleton, Hampton	86 min
Jul 28, 7:48 AM EDT	Areal Flood Advisory	CHS	Berkeley, Charleston, Colleton, Dorchester	42 min
Jul 28, 9:35 AM EDT	Areal Flood Advisory	CHS	Charleston, Colleton, Dorchester	85 min
Jul 27, 8:45 PM EDT	Special Weather Statement	CHS	Long	30 min
Jul 27, 11:38 PM EDT	Areal Flood Advisory	CHS	Bulloch, Jenkins, Screven	82 min

Nearby

Areal Flood Advisories in South Carolina, 2021 Every areal flood advisory in 2021

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.