Alert archive / South Carolina / Areal Flood Advisories in 2021

Areal Flood Advisory 99, NWS Charleston, SC

August 19, 2021Berkeley County, Charleston County, Dorchester County, South Carolina

NWS Charleston, SC issued this areal flood advisory at Aug 19, 2021, 5:35 PM EDT for Berkeley County, Charleston County, Dorchester County, South Carolina. It was in force for 115 min.

The area

The counties it named.

The facts

Issued
Aug 19, 2021, 5:35 PM EDT (21:35 UTC)
Expired
Aug 19, 2021, 7:30 PM EDT
In force
115 min
Issued by
NWS Charleston, SC
Area
Storm-based polygon

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

The radar

The Charleston,SC radar (KCLX), 96 km from the middle of the area, began a volume at 21:35 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, 9.6 hours before the alert went out and 317 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, Jacksonville, FL at 12:00Z on 2021-08-19Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1604 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, Jacksonville, FL at 12:00Z on 2021-08-19The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 0 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
1604 J/kg
Mixed-layer CIN
-33 J/kg
Mixed-layer LCL
844 m above ground
0-6 km bulk shear
3 kt
0-1 km storm-relative helicity
0 m²/s²
0-3 km storm-relative helicity
7 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 Aug 19, 4:00 PM EDT, 1 hour 35 minutes earlier.

Area forecast discussion, Aug 19, 4:00 PM EDT, 1 hour 35 minutes before
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Hazardous weather outlook, Aug 19, 3:41 PM EDT, 1 hour 54 minutes before
Hazardous Weather Outlook
National Weather Service Charleston SC
341 PM EDT Thu Aug 19 2021

AMZ330-350-352-354-374-201945-
Charleston Harbor-
Waters from South Santee River to Edisto Beach SC out 20 NM-
Waters from Edisto Beach SC to Savannah GA out 20 NM-
Waters from Savannah GA to Altamaha Sound GA out 20 NM, including
Grays Reef National Marine Sanctuary-
Waters from Savannah GA to Altamaha Sound GA from 20 to 60 NM-
341 PM EDT Thu Aug 19 2021

This Hazardous Weather Outlook is for Atlantic coastal waters.

.DAY ONE...This afternoon and tonight.

The probability for widespread hazardous weather is low.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday.

The probability for widespread hazardous weather is low.

.SPOTTER INFORMATION STATEMENT...

Spotter assistance is not anticipated at this time.

GAZ087-088-099>101-114>116-118-137-138-140-SCZ040-042>045-047-052-
201945-
Jenkins-Screven-Candler-Bulloch-Effingham-Tattnall-Evans-
Inland Bryan-Inland Chatham-Long-Inland Liberty-Inland McIntosh-
Allendale-Hampton-Inland Colleton-Dorchester-Inland Berkeley-
Inland Jasper-Tidal Berkeley-
341 PM EDT Thu Aug 19 2021

This Hazardous Weather Outlook is for southeast Georgia and
southeast South Carolina.

.DAY ONE...This afternoon and tonight.

The probability for widespread hazardous weather is low.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday.

The probability for widespread hazardous weather is low.

.SPOTTER INFORMATION STATEMENT...

Spotter assistance is not anticipated at this time.

SCZ049-050-201945-
Coastal Colleton-Charleston-
341 PM EDT Thu Aug 19 2021

...MODERATE RISK FOR RIP CURRENTS IN EFFECT THROUGH FRIDAY EVENING...

This Hazardous Weather Outlook is for southeast South Carolina.

.DAY ONE...This afternoon and tonight.

Please listen to NOAA Weather Radio or go to weather.gov on the
Internet for more information about the following hazards.

   Moderate Risk for Rip Currents.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday.

Please listen to NOAA Weather Radio or go to weather.gov on the
Internet for more information about the following hazards.

   Moderate Risk for Rip Currents.

Coastal Flooding...Tide levels are forecast to reach marginal
Coastal Flood Advisory levels around Charleston during the Friday
night high tide and possibly Saturday night as well, mainly due to
the full moon and swells from tropical cyclone Henri well offshore.
Thus, minor coastal flooding will be possible, with flooding being
exacerbated if heavy rain falls around the same time.

.SPOTTER INFORMATION STATEMENT...

Spotter assistance is not anticipated at this time.

GAZ117-119-139-141-SCZ048-051-201945-
Coastal Bryan-Coastal Chatham-Coastal Liberty-Coastal McIntosh-
Beaufort-Coastal Jasper-
341 PM EDT Thu Aug 19 2021

...MODERATE RISK FOR RIP CURRENTS IN EFFECT THROUGH FRIDAY EVENING...

This Hazardous Weather Outlook is for southeast Georgia and
southeast South Carolina.

.DAY ONE...This afternoon and tonight.

Please listen to NOAA Weather Radio or go to weather.gov on the
Internet for more information about the following hazards.

   Moderate Risk for Rip Currents.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday.

Please listen to NOAA Weather Radio or go to weather.gov on the
Internet for more information about the following hazards.

   Moderate Risk for Rip Currents.

.SPOTTER INFORMATION STATEMENT...

Spotter assistance is not anticipated at this time.

In the hours before

Local storm report, Aug 19, 4:23 PM EDT, 1 hour 12 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHARLESTON SC
423 PM EDT THU AUG 19 2021

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0200 PM     RIP CURRENTS     TYBEE ISLAND            31.99N  80.85W
08/19/2021                   CHATHAM            GA   LIFEGUARD

            NUMEROUS RIP CURRENTS HAVE BEEN SPOTTED BY THE TYBEE
            ISLAND LIFEGUARDS THROUGHOUT THE AFTERNOON SOUTH OF 7TH
            STREET. THERE WERE THREE ASSISTS JUST SOUTH OF THE PIER
            AROUND 2 PM WITH NO INJURIES REPORTED.

&&

EVENT NUMBER CHS2100573

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 19, 6:12 PM EDTAreal Flood AdvisoryCHSCharleston60 min
Aug 19, 6:25 PM EDTSpecial Weather StatementCHSDorchester35 min
Aug 19, 6:31 PM EDTSevere Thunderstorm WarningCHSBerkeley, Dorchester59 min
Aug 19, 6:55 PM EDTSpecial Weather StatementCHSBerkeley35 min
Aug 19, 7:08 PM EDTSpecial Weather StatementCHSBerkeley37 min
Aug 19, 7:28 PM EDTSpecial Weather StatementCHSBerkeley32 min
Aug 19, 7:45 PM EDTSpecial Weather StatementCHSBerkeley30 min
Aug 19, 7:57 PM EDTSpecial Weather StatementCHSBerkeley33 min

Nearby

Areal Flood Advisories in South Carolina, 2021Every 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.