Alert archive / South Carolina / Flash Flood Watches in 2021

Flash Flood Watch 6, NWS Charleston, SC

September 20, 20214 counties in South Carolina; Effingham County, Georgia

NWS Charleston, SC issued this flash flood watch at Sep 20, 2021, 3:16 AM EDT for 4 counties in South Carolina; Effingham County, Georgia. It was in force for 36 hr.

The area

The counties it named.

The facts

Issued
Sep 20, 2021, 3:16 AM EDT (07:16 UTC)
Expired
Sep 21, 2021, 2:49 PM EDT
In force
36 hr
Issued by
NWS Charleston, SC
Flood severity
None

Counties Effingham County, GA, Berkeley County, SC, Colleton County, SC, Dorchester County, SC, Hampton County, SC

The radar

The Charleston,SC radar (KCLX), 39 km from the middle of the area, began a volume at 07:14 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

Charleston AFB, SC (KCHS), launched 00:00Z, 7.3 hours before the alert went out and 65 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, Charleston AFB, SC at 00:00Z on 2021-09-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 75 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Charleston AFB, SC at 00:00Z on 2021-09-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -26 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
75 J/kg
Mixed-layer CIN
-55 J/kg
Mixed-layer LCL
1011 m above ground
0-6 km bulk shear
6 kt
0-1 km storm-relative helicity
-26 m²/s²
0-3 km storm-relative helicity
3 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

352 
WGUS62 KCHS 200716
FFACHS

URGENT - IMMEDIATE BROADCAST REQUESTED
Flood Watch
National Weather Service Charleston SC
316 AM EDT Mon Sep 20 2021

GAZ101-116>119-138>141-SCZ042>045-047>052-201530-
/O.NEW.KCHS.FF.A.0006.210920T0716Z-210921T1000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Effingham-Inland Bryan-Coastal Bryan-Inland Chatham-Coastal Chatham-
Inland Liberty-Coastal Liberty-Inland McIntosh-Coastal McIntosh-
Hampton-Inland Colleton-Dorchester-Inland Berkeley-Inland Jasper-
Beaufort-Coastal Colleton-Charleston-Coastal Jasper-Tidal Berkeley-
Including the cities of Edisto Beach, Mount Pleasant, Walterboro, 
Charleston, Townsend, Fort Stewart, Levy, Daniel Island, Tybee 
Island, Rincon, Hilton Head Island, Richmond Hill, Springfield, 
Summerville, Garden City, Beaufort, Pembroke, North Charleston, 
Yemassee, Ridgeland, Pooler, Goose Creek, Hinesville, Chelsea, 
Hampton, Oak Level, Saint George, Savannah, Moncks Corner, 
Wilmington Island, Jasper, Fort Mcallister, and Darien
316 AM EDT Mon Sep 20 2021

...FLASH FLOOD WATCH IN EFFECT THROUGH LATE TONIGHT...

The National Weather Service in Charleston has issued a

* Flash Flood Watch for portions of southeast Georgia and southeast 
  South Carolina, including the following areas, in southeast 
  Georgia, Coastal Bryan, Coastal Chatham, Coastal Liberty, Coastal 
  McIntosh, Effingham, Inland Bryan, Inland Chatham, Inland Liberty 
  and Inland McIntosh. In southeast South Carolina, Beaufort, 
  Charleston, Coastal Colleton, Coastal Jasper, Dorchester, Hampton, 
  Inland Berkeley, Inland Colleton, Inland Jasper and Tidal Berkeley.

* Through late tonight.

* Widespread showers and isolated thunderstorms with torrential rain 
  will overspread much of Southeast South Carolina and Southeast 
  Georgia today and tonight. Rainfall amounts of 2 to 4 inches with 
  localized amounts in excess of 6 inches could fall through 6 AM 
  Tuesday. This could result in pockets of flash flooding. The risk 
  for flash flooding could become enhanced along the coast during 
  high tide this morning and again this evening where tide levels 
  are already elevated. This includes both the Charleston and 
  Savannah Metro Areas.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be prepared to take action 
should Flash Flood Warnings be issued.

&&

$$
7 follow-up statements
755 
WGUS62 KCHS 201020
FFACHS

Flood Watch
National Weather Service Charleston SC
620 AM EDT Mon Sep 20 2021

GAZ101-116>119-138>141-SCZ042>045-047>052-201830-
/O.CON.KCHS.FF.A.0006.000000T0000Z-210921T1000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Effingham-Inland Bryan-Coastal Bryan-Inland Chatham-Coastal Chatham-
Inland Liberty-Coastal Liberty-Inland McIntosh-Coastal McIntosh-
Hampton-Inland Colleton-Dorchester-Inland Berkeley-Inland Jasper-
Beaufort-Coastal Colleton-Charleston-Coastal Jasper-Tidal Berkeley-
Including the cities of Edisto Beach, Mount Pleasant, Walterboro, 
Charleston, Townsend, Fort Stewart, Levy, Daniel Island, Tybee 
Island, Rincon, Hilton Head Island, Richmond Hill, Springfield, 
Summerville, Garden City, Beaufort, Pembroke, North Charleston, 
Yemassee, Ridgeland, Pooler, Goose Creek, Hinesville, Chelsea, 
Hampton, Oak Level, Saint George, Savannah, Moncks Corner, 
Wilmington Island, Jasper, Fort Mcallister, and Darien
620 AM EDT Mon Sep 20 2021

...FLASH FLOOD WATCH REMAINS IN EFFECT THROUGH LATE TONIGHT...

The Flash Flood Watch continues for

* Portions of southeast Georgia and southeast South Carolina, 
  including the following areas, in southeast Georgia, Coastal 
  Bryan, Coastal Chatham, Coastal Liberty, Coastal McIntosh, 
  Effingham, Inland Bryan, Inland Chatham, Inland Liberty and Inland 
  McIntosh. In southeast South Carolina, Beaufort, Charleston, 
  Coastal Colleton, Coastal Jasper, Dorchester, Hampton, Inland 
  Berkeley, Inland Colleton, Inland Jasper and Tidal Berkeley.

* Through late tonight.

* Widespread showers and isolated thunderstorms with torrential rain 
  will overspread much of Southeast South Carolina and Southeast 
  Georgia today and tonight. Rainfall amounts of 2 to 4 inches with 
  localized amounts in excess of 6 inches could fall through 6 AM 
  Tuesday. This could result in pockets of flash flooding. The risk 
  for flash flooding could become enhanced along the coast during 
  high tide this morning and again this evening where tide levels 
  are already elevated. This includes both the Charleston and 
  Savannah Metro Areas.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Be prepared to protect life and property, especially in areas prone 
to flooding. If flooding develops, move to higher ground 
immediately. If driving, be prepared for flooded roadways and 
possible road closures.

&&

$$
233 
WGUS62 KCHS 201713
FFACHS

Flood Watch
National Weather Service Charleston SC
113 PM EDT Mon Sep 20 2021

GAZ101-116>119-138>141-SCZ042>045-047>052-210115-
/O.CON.KCHS.FF.A.0006.000000T0000Z-210921T1000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Effingham-Inland Bryan-Coastal Bryan-Inland Chatham-Coastal Chatham-
Inland Liberty-Coastal Liberty-Inland McIntosh-Coastal McIntosh-
Hampton-Inland Colleton-Dorchester-Inland Berkeley-Inland Jasper-
Beaufort-Coastal Colleton-Charleston-Coastal Jasper-Tidal Berkeley-
Including the cities of Edisto Beach, Mount Pleasant, Walterboro, 
Charleston, Townsend, Fort Stewart, Levy, Daniel Island, Tybee 
Island, Rincon, Hilton Head Island, Richmond Hill, Springfield, 
Summerville, Garden City, Beaufort, Pembroke, North Charleston, 
Yemassee, Ridgeland, Pooler, Goose Creek, Hinesville, Chelsea, 
Hampton, Oak Level, Saint George, Savannah, Moncks Corner, 
Wilmington Island, Jasper, Fort Mcallister, and Darien
113 PM EDT Mon Sep 20 2021

...FLASH FLOOD WATCH REMAINS IN EFFECT THROUGH LATE TONIGHT...

The Flash Flood Watch continues for

* Portions of southeast Georgia and southeast South Carolina, 
  including the following areas, in southeast Georgia, Coastal 
  Bryan, Coastal Chatham, Coastal Liberty, Coastal McIntosh, 
  Effingham, Inland Bryan, Inland Chatham, Inland Liberty and Inland 
  McIntosh. In southeast South Carolina, Beaufort, Charleston, 
  Coastal Colleton, Coastal Jasper, Dorchester, Hampton, Inland 
  Berkeley, Inland Colleton, Inland Jasper and Tidal Berkeley.

* Through late tonight.

* Widespread showers and a few thunderstorms will continue to impact 
  southeast South Carolina and southeast Georgia through tonight. 
  Overall rainfall amounts of 2 to 4 inches are expected through 6 
  am Tuesday with localized amounts up to 6 inches possible. The 
  risk for flooding may be enhanced along the coast during high tide 
  this evening.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Be prepared to protect life and property, especially in areas prone 
to flooding. If flooding develops, move to higher ground 
immediately. If driving, be prepared for flooded roadways and 
possible road closures.

&&

$$
364 
WGUS62 KCHS 202006
FFACHS

Flood Watch
National Weather Service Charleston SC
406 PM EDT Mon Sep 20 2021

GAZ101-116>119-138>141-SCZ042>045-047>052-210415-
/O.CON.KCHS.FF.A.0006.000000T0000Z-210921T1000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Effingham-Inland Bryan-Coastal Bryan-Inland Chatham-Coastal Chatham-
Inland Liberty-Coastal Liberty-Inland McIntosh-Coastal McIntosh-
Hampton-Inland Colleton-Dorchester-Inland Berkeley-Inland Jasper-
Beaufort-Coastal Colleton-Charleston-Coastal Jasper-Tidal Berkeley-
Including the cities of Edisto Beach, Mount Pleasant, Walterboro, 
Charleston, Townsend, Fort Stewart, Levy, Daniel Island, Tybee 
Island, Rincon, Hilton Head Island, Richmond Hill, Springfield, 
Summerville, Garden City, Beaufort, Pembroke, North Charleston, 
Yemassee, Ridgeland, Pooler, Goose Creek, Hinesville, Chelsea, 
Hampton, Oak Level, Saint George, Savannah, Moncks Corner, 
Wilmington Island, Jasper, Fort Mcallister, and Darien
406 PM EDT Mon Sep 20 2021

...FLASH FLOOD WATCH REMAINS IN EFFECT THROUGH LATE TONIGHT...

The Flash Flood Watch continues for

* Portions of southeast Georgia and southeast South Carolina, 
  including the following areas, in southeast Georgia, Coastal 
  Bryan, Coastal Chatham, Coastal Liberty, Coastal McIntosh, 
  Effingham, Inland Bryan, Inland Chatham, Inland Liberty and Inland 
  McIntosh. In southeast South Carolina, Beaufort, Charleston, 
  Coastal Colleton, Coastal Jasper, Dorchester, Hampton, Inland 
  Berkeley, Inland Colleton, Inland Jasper and Tidal Berkeley.

* Through late tonight.

* Widespread showers and a few thunderstorms will continue to impact 
  southeast South Carolina and southeast Georgia through tonight. 
  Overall rainfall amounts of 2 to 4 inches are expected through 
  6 am Tuesday with localized amounts up to 6 inches possible. The 
  risk for flooding may be enhanced along the coast during high tide 
  this evening.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Be prepared to protect life and property, especially in areas prone 
to flooding. If flooding develops, move to higher ground 
immediately. If driving, be prepared for flooded roadways and 
possible road closures.

&&

$$
997 
WGUS62 KCHS 202339
FFACHS

URGENT - IMMEDIATE BROADCAST REQUESTED
Flood Watch
National Weather Service Charleston SC
739 PM EDT Mon Sep 20 2021

GAZ101-116>119-138>141-SCZ042>045-047>052-210745-
/O.EXT.KCHS.FF.A.0006.000000T0000Z-210921T1600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Effingham-Inland Bryan-Coastal Bryan-Inland Chatham-Coastal Chatham-
Inland Liberty-Coastal Liberty-Inland McIntosh-Coastal McIntosh-
Hampton-Inland Colleton-Dorchester-Inland Berkeley-Inland Jasper-
Beaufort-Coastal Colleton-Charleston-Coastal Jasper-Tidal Berkeley-
Including the cities of Edisto Beach, Mount Pleasant, Walterboro, 
Charleston, Townsend, Fort Stewart, Levy, Daniel Island, Tybee 
Island, Rincon, Hilton Head Island, Richmond Hill, Springfield, 
Summerville, Garden City, Beaufort, Pembroke, North Charleston, 
Yemassee, Ridgeland, Pooler, Goose Creek, Hinesville, Chelsea, 
Hampton, Oak Level, Saint George, Savannah, Moncks Corner, 
Wilmington Island, Jasper, Fort Mcallister, and Darien
739 PM EDT Mon Sep 20 2021

...FLASH FLOOD WATCH NOW IN EFFECT THROUGH TUESDAY MORNING...

The Flash Flood Watch is now in effect for

* Portions of southeast Georgia and southeast South Carolina, 
  including the following areas, in southeast Georgia, Coastal 
  Bryan, Coastal Chatham, Coastal Liberty, Coastal McIntosh, 
  Effingham, Inland Bryan, Inland Chatham, Inland Liberty and Inland 
  McIntosh. In southeast South Carolina, Beaufort, Charleston, 
  Coastal Colleton, Coastal Jasper, Dorchester, Hampton, Inland 
  Berkeley, Inland Colleton, Inland Jasper and Tidal Berkeley.

* Through Tuesday morning.

* Rounds of heavy rainfall producing showers, and possibly a 
  thunderstorm or two, will continue to impact much of southeast 
  Georgia and southeast South Carolina through Tuesday morning. 
  Additional rainfall amounts of 2 to 4 inches will be possible, 
  with locally higher amounts possible. The risk for flash flooding 
  could be enhanced along the coast during high tide, especially 
  along the Charleston County coast with the high tide around 9 am 
  Tuesday morning.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Be prepared to protect life and property, especially in areas prone 
to flooding. If flooding develops, move to higher ground 
immediately. If driving, be prepared for flooded roadways and 
possible road closures.

&&

$$

BSH
002 
WGUS62 KCHS 210724
FFACHS

URGENT - IMMEDIATE BROADCAST REQUESTED
Flood Watch
National Weather Service Charleston SC
324 AM EDT Tue Sep 21 2021

GAZ116-117-138>141-210830-
/O.CAN.KCHS.FF.A.0006.000000T0000Z-210921T1600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Inland Bryan-Coastal Bryan-Inland Liberty-Coastal Liberty-Inland
McIntosh-Coastal McIntosh-
Including the cities of Pembroke, Oak Level, Richmond Hill, Fort 
Mcallister, Hinesville, Darien, Townsend, and Fort Stewart
324 AM EDT Tue Sep 21 2021

...FLASH FLOOD WATCH IS CANCELLED...

The Flash Flood Watch for a portion of Southeast Georgia, including 
the following areas, Coastal Bryan, Coastal Liberty, Coastal 
McIntosh, Inland Bryan, Inland Liberty and Inland McIntosh has been 
cancelled.

The risk for flash flooding has ended. Localized flooding could 
still occur today into this evening, mainly in low-lying and poor 
drainage areas.

$$

GAZ101-118-119-SCZ042>045-047>052-211530-
/O.EXT.KCHS.FF.A.0006.000000T0000Z-210922T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Effingham-Inland Chatham-Coastal Chatham-Hampton-Inland Colleton-
Dorchester-Inland Berkeley-Inland Jasper-Beaufort-Coastal Colleton-
Charleston-Coastal Jasper-Tidal Berkeley-
Including the cities of Edisto Beach, Mount Pleasant, Walterboro, 
Springfield, Levy, Daniel Island, Tybee Island, Rincon, Hilton Head 
Island, Summerville, Garden City, Beaufort, North Charleston, 
Yemassee, Ridgeland, Pooler, Goose Creek, Charleston, Chelsea, 
Hampton, Saint George, Savannah, Moncks Corner, Wilmington Island, 
and Jasper
324 AM EDT Tue Sep 21 2021

...FLASH FLOOD WATCH NOW IN EFFECT THROUGH THIS EVENING...

The Flash Flood Watch is now in effect for

* Portions of southeast Georgia and southeast South Carolina, 
  including the following areas, in southeast Georgia, Coastal 
  Chatham, Effingham and Inland Chatham. In southeast South 
  Carolina, Beaufort, Charleston, Coastal Colleton, Coastal Jasper, 
  Dorchester, Hampton, Inland Berkeley, Inland Colleton, Inland 
  Jasper and Tidal Berkeley.

* Through this evening.

* Numerous to widespread showers with occasional thunderstorms will 
  impact much of Southeast South Carolina into far eastern parts of 
  Georgia through this evening. Additional rainfall amounts of 2 to 
  4 inches with localized amounts in excess of 5 inches are possible 
  with 1 to 2 inches possible over portions of far eastern Georgia, 
  including the Savannah Metro Area. Many areas observed between 2 
  to 5 inches of rain yesterday with some spots seeing greater than 
  8 inches in portions of Beaufort County. The risk for flash 
  flooding continues.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Be prepared to protect life and property, especially in areas prone 
to flooding. If flooding develops, move to higher ground 
immediately. If driving, be prepared for flooded roadways and 
possible road closures.

&&

$$
211 
WGUS62 KCHS 211348
FFACHS

Flood Watch
National Weather Service Charleston SC
948 AM EDT Tue Sep 21 2021

GAZ101-118-119-SCZ042>045-047>052-212200-
/O.CON.KCHS.FF.A.0006.000000T0000Z-210922T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Effingham-Inland Chatham-Coastal Chatham-Hampton-Inland Colleton-
Dorchester-Inland Berkeley-Inland Jasper-Beaufort-Coastal Colleton-
Charleston-Coastal Jasper-Tidal Berkeley-
Including the cities of Edisto Beach, Mount Pleasant, Walterboro, 
Springfield, Levy, Daniel Island, Tybee Island, Rincon, Hilton Head 
Island, Summerville, Garden City, Beaufort, North Charleston, 
Yemassee, Ridgeland, Pooler, Goose Creek, Charleston, Chelsea, 
Hampton, Saint George, Savannah, Moncks Corner, Wilmington Island, 
and Jasper
948 AM EDT Tue Sep 21 2021

...FLASH FLOOD WATCH REMAINS IN EFFECT UNTIL 8 PM EDT THIS EVENING...

The Flash Flood Watch continues for

* Portions of southeast Georgia and southeast South Carolina, 
  including the following areas, in southeast Georgia, Coastal 
  Chatham, Effingham and Inland Chatham. In southeast South 
  Carolina, Beaufort, Charleston, Coastal Colleton, Coastal Jasper, 
  Dorchester, Hampton, Inland Berkeley, Inland Colleton, Inland 
  Jasper and Tidal Berkeley.

* Until 8 PM EDT this evening.

* Pockets of heavy rainfall will impact much of southeast South 
  Carolina into far eastern parts of Georgia through this evening. 
  Additional rainfall amounts of 1 to 3 inches with localized higher 
  amounts are possible. Given the recent heavy rainfall in many 
  areas it will not take as much additional rainfall to cause flash 
  flooding.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Be prepared to protect life and property, especially in areas prone 
to flooding. If flooding develops, move to higher ground 
immediately. If driving, be prepared for flooded roadways and 
possible road closures.

&&

$$
493 
WGUS62 KCHS 211849
FFACHS

Flood Watch
National Weather Service Charleston SC
249 PM EDT Tue Sep 21 2021

GAZ101-118-119-SCZ042>045-047>052-212000-
/O.CAN.KCHS.FF.A.0006.000000T0000Z-210922T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Effingham-Inland Chatham-Coastal Chatham-Hampton-Inland Colleton-
Dorchester-Inland Berkeley-Inland Jasper-Beaufort-Coastal Colleton-
Charleston-Coastal Jasper-Tidal Berkeley-
Including the cities of Edisto Beach, Mount Pleasant, Walterboro, 
Springfield, Levy, Daniel Island, Tybee Island, Rincon, Hilton Head 
Island, Summerville, Garden City, Beaufort, North Charleston, 
Yemassee, Ridgeland, Pooler, Goose Creek, Charleston, Chelsea, 
Hampton, Saint George, Savannah, Moncks Corner, Wilmington Island, 
and Jasper
249 PM EDT Tue Sep 21 2021

...FLASH FLOOD WATCH IS CANCELLED...

The Flash Flood Watch for portions of southeast Georgia and 
southeast South Carolina, including the following areas, in 
southeast Georgia, Coastal Chatham, Effingham and Inland Chatham. In 
southeast South Carolina, Beaufort, Charleston, Coastal Colleton, 
Coastal Jasper, Dorchester, Hampton, Inland Berkeley, Inland 
Colleton, Inland Jasper and Tidal Berkeley has been cancelled.

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 20, 2:50 AM EDTCoastal Flood AdvisoryCHS7 hr
Sep 20, 5:48 AM EDTAreal Flood AdvisoryCHSBeaufort, Charleston, Colleton, Jasper117 min
Sep 20, 7:37 AM EDTAreal Flood AdvisoryCHSBeaufort, Charleston, Colleton113 min
Sep 20, 8:56 AM EDTSmall Craft AdvisoryCHS13 hr
Sep 20, 1:30 PM EDTSpecial Marine WarningCHS2 hr
Sep 20, 3:31 PM EDTSpecial Marine WarningCHS119 min
Sep 20, 3:34 PM EDTCoastal Flood AdvisoryCHS7 hr
Sep 20, 6:40 PM EDTAreal Flood AdvisoryCHSBeaufort, Jasper3 hr
Sep 20, 7:53 PM EDTAreal Flood AdvisoryCHSChatham4 hr

Nearby

Flash Flood Watches in South Carolina, 2021Flash Flood Watches in Georgia, 2021Every flash flood watch 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.