Alert archive / South Carolina / Areal Flood Advisories in 2020

Areal Flood Advisory 21, NWS Charleston, SC

April 23, 20204 counties in South Carolina

NWS Charleston, SC issued this areal flood advisory at Apr 23, 2020, 6:45 PM EDT for 4 counties in South Carolina. It was in force for 6 hr.

The area

The counties it named.

The facts

Issued: Apr 23, 2020, 6:45 PM EDT (22:45 UTC)
Expired: Apr 24, 2020, 12:15 AM EDT
In force: 6 hr
Issued by: NWS Charleston, SC
Area: Storm-based polygon

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

The radar

The Charleston,SC radar (KCLX), 83 km from the middle of the area, began a volume at 22:46 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, 10.8 hours before the alert went out and 307 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: 1362 m above ground
0-6 km bulk shear: 62 kt
0-1 km storm-relative helicity: 108 m²/s²
0-3 km storm-relative helicity: 225 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 Apr 23, 5:18 PM EDT, 1 hour 27 minutes earlier.

Area forecast discussion, Apr 23, 5:18 PM EDT, 1 hour 27 minutes before

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Hazardous weather outlook, Apr 23, 5:12 PM EDT, 1 hour 33 minutes before

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In the hours before

Special weather statement, Apr 23, 3:40 PM EDT, 3 hours 5 minutes before

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Local storm report, Apr 23, 3:43 PM EDT, 3 hours 2 minutes before

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Local storm report, Apr 23, 4:32 PM EDT, 2 hours 13 minutes before

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Local storm report, Apr 23, 4:34 PM EDT, 2 hours 11 minutes before

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Local storm report, Apr 23, 4:47 PM EDT, 1 hour 58 minutes before

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Local storm report, Apr 23, 4:52 PM EDT, 1 hour 53 minutes before

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      <p id="message2">
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The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 23, 3:13 AM EDT	Lake Wind Advisory	CHS	Berkeley	13 hr
Apr 23, 3:13 AM EDT	Wind Advisory	CHS		11 hr
Apr 23, 3:19 AM EDT	Gale Warning	CHS		13 hr
Apr 23, 1:48 PM EDT	Special Weather Statement	CHS	Allendale	27 min
Apr 23, 2:27 PM EDT	Small Craft Advisory	CHS		29 hr
Apr 23, 3:07 PM EDT	Special Marine Warning	CHS		113 min
Apr 23, 5:31 PM EDT	Areal Flood Advisory	CHS	Beaufort, Berkeley, Charleston, Colleton, Dorchester, Hampton and 1 more	89 min
Apr 23, 7:04 PM EDT	Special Marine Warning	CHS		41 min
Apr 23, 7:28 PM EDT	Special Marine Warning	CHS		59 min
Apr 23, 2:01 PM EDT	Special Weather Statement	CHS	Screven	29 min
Apr 23, 2:40 PM EDT	Severe Thunderstorm Warning	CHS	Liberty, McIntosh	65 min
Apr 23, 2:59 PM EDT	Tornado Warning Tornado observedConsiderable damage threat	CHS	McIntosh	46 min
Apr 23, 3:37 PM EDT	Severe Thunderstorm Warning	CHS	Liberty, McIntosh	24 min
Apr 23, 3:40 PM EDT	Special Weather Statement	CHS	Effingham	35 min

Nearby

Areal Flood Advisories in South Carolina, 2020 Every areal flood advisory 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.