Alert archive / Georgia / Flash Flood Warnings in 2007

Flash Flood Warning 18, NWS Charleston, SC

September 21, 2007Chatham County, Georgia

NWS Charleston, SC issued this flash flood warning at Sep 21, 2007, 11:26 AM EDT for Chatham County, Georgia. It was in force for 2 hr. 1 report came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: Sep 21, 2007, 11:26 AM EDT (15:26 UTC)
Expired: Sep 21, 2007, 1:30 PM EDT
In force: 2 hr
Issued by: NWS Charleston, SC
Area: Counties, with a storm outline in the text
Flood severity: None

County Chatham County, GA

The radar

The Charleston,SC radar (KCLX), 78 km from the middle of the area, began a volume at 15:29 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.

What was reported inside it

Time	Report	Where	Remark
Sep 21, 1:00 PM EDT	HEAVY RAIN 4.85	Skidaway Island, GA	RAINFALL SINCE 10 AM. 4.00 FELL BETWEEN 10 AND 11 AM.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Charleston AFB, SC (KCHS), launched 12:00Z, 3.4 hours before the alert went out and 141 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: 267 J/kg
Mixed-layer CIN: -21 J/kg
Mixed-layer LCL: 576 m above ground
0-6 km bulk shear: 22 kt
0-1 km storm-relative helicity: 106 m²/s²
0-3 km storm-relative helicity: 132 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.2

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

000 
WGUS52 KCHS 211528
FFWCHS
GAC051-211730-
/X.NEW.KCHS.FF.W.0018.070921T1526Z-070921T1730Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE CHARLESTON SC
1126 AM EDT FRI SEP 21 2007

THE NATIONAL WEATHER SERVICE IN CHARLESTON HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  CHATHAM COUNTY IN SOUTHEAST GEORGIA...

* UNTIL 130 PM EDT

* AT 1125 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  VERY HEAVY RAIN OCCURRING NEAR SKIDAWAY ISLAND...OR ABOUT 13 MILES
  SOUTH OF SAVANNAH. THE AREA OF HEAVY RAIN WAS NEARLY STATIONARY.

* FLASH FLOODING IS EXPECTED IN AND AROUND...
  SKIDAWAY ISLAND...ISLE OF HOPE...
  WILMINGTON ISLAND...SAVANNAH...

SOME STREET FLOODING HAS ALREADY BEEN REPORTED ON VICORY DRIVE AND 
AND ALSO AT THE INTERSECTION OF PAULSON RD AND SIXTY THIRD STREET.

MOST FLOOD DEATHS OCCUR IN AUTOMOBILES. NEVER DRIVE YOUR VEHICLE INTO
AREAS WHERE THE WATER COVERS THE ROADWAY. FLOOD WATERS ARE USUALLY
DEEPER THAN THEY APPEAR. JUST ONE FOOT OF FLOWING WATER IS POWERFUL
ENOUGH TO SWEEP VEHICLES OFF THE ROAD. WHEN ENCOUNTERING FLOODED
ROADS MAKE THE SMART CHOICE...TURN AROUND...DONT DROWN.

TO REPORT SIGNIFICANT FLOODING...PLEASE CONTACT THE NATIONAL WEATHER
SERVICE IN CHARLESTON TOLL FREE AT 1-888-383-2024.

LAT...LON 3191 8115 3208 8110 3208 8100 3203 8088
      3194 8092 3195 8095 3193 8097 3192 8093
      3190 8094 3185 8101
TIME...MOT...LOC 1526Z 180DEG 0KT 3187 8103

$$

2 follow-up statements

000 
WGUS72 KCHS 211637
FFSCHS

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE CHARLESTON SC
1234 PM EDT FRI SEP 21 2007

GAC051-211730-
/X.CON.KCHS.FF.W.0018.000000T0000Z-070921T1730Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
CHATHAM GA-
1234 PM EDT FRI SEP 21 2007

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 130 PM EDT FOR
CHATHAM COUNTY...

AT 1233 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED 
THAT THE HEAVIEST RAIN HAS MOVED OUT OF THE WARNED AREA. 
HOWEVER...LOCAL OFFICIALS INDICATE THAT FLOODING CONTINUES ACROSS 
MANY STREETS IN AND AROUND DOWNTOWN SAVANNAH.

MOST FLOOD DEATHS OCCUR IN AUTOMOBILES. NEVER DRIVE YOUR VEHICLE INTO
AREAS WHERE THE WATER COVERS THE ROADWAY. FLOOD WATERS ARE USUALLY
DEEPER THAN THEY APPEAR. JUST ONE FOOT OF FLOWING WATER IS POWERFUL
ENOUGH TO SWEEP VEHICLES OFF THE ROAD. WHEN ENCOUNTERING FLOODED
ROADS MAKE THE SMART CHOICE...TURN AROUND...DONT DROWN.

TO REPORT SIGNIFICANT FLOODING...PLEASE CONTACT THE NATIONAL WEATHER
SERVICE IN CHARLESTON TOLL FREE AT 1-888-383-2024 OR EMAIL YOUR
REPORTS TO CHS.SKYWARN@NOAA.GOV.

LAT...LON 3191 8115 3208 8110 3208 8100 3203 8088
      3194 8092 3195 8095 3193 8097 3192 8093
      3190 8094 3185 8101
TIME...MOT...LOC 1634Z 180DEG 0KT 3187 8103

$$

000 
WGUS72 KCHS 211709
FFSCHS

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE CHARLESTON SC
108 PM EDT FRI SEP 21 2007

GAC051-211718-
/X.CAN.KCHS.FF.W.0018.000000T0000Z-070921T1730Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
CHATHAM GA-
108 PM EDT FRI SEP 21 2007

...THE FLASH FLOOD WARNING HAS BEEN CANCELLED FOR CHATHAM COUNTY...

LOCAL OFFICIALS REPORT THE FLOODING HAS SUBSIDED AND WITH NO 
ADDITIONAL RAINFALL IMMINENT...THE WARNING HAS BEEN CANCELLED.

TO REPORT SIGNIFICANT FLOODING...PLEASE CONTACT THE NATIONAL WEATHER
SERVICE IN CHARLESTON TOLL FREE AT 1-888-383-2024 OR EMAIL YOUR
REPORTS TO CHS.SKYWARN@NOAA.GOV.

LAT...LON 3191 8115 3208 8110 3208 8100 3203 8088
      3194 8092 3195 8095 3193 8097 3192 8093
      3190 8094 3185 8101
TIME...MOT...LOC 1708Z 180DEG 0KT 3187 8103

$$

The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 21, 5:49 AM EDT	Severe Thunderstorm Warning	CHS	McIntosh	56 min
Sep 21, 6:30 AM EDT	Tornado Warning	CHS	McIntosh	30 min
Sep 21, 7:09 AM EDT	Tornado Warning	CHS	McIntosh	36 min
Sep 21, 7:22 AM EDT	Areal Flood Advisory	CHS	McIntosh	113 min
Sep 21, 7:28 AM EDT	Special Marine Warning	CHS		62 min
Sep 21, 7:35 AM EDT	Severe Thunderstorm Warning	CHS	Liberty	40 min
Sep 21, 7:52 AM EDT	Areal Flood Advisory	CHS	Liberty	113 min
Sep 21, 8:22 AM EDT	Special Marine Warning	CHS		53 min
Sep 21, 8:58 AM EDT	Severe Thunderstorm Warning	CHS	Bryan, Chatham, Liberty	47 min
Sep 21, 9:04 AM EDT	Areal Flood Advisory	CHS	Liberty	116 min
Sep 21, 9:13 AM EDT	Special Marine Warning	CHS		62 min
Sep 21, 9:15 AM EDT	Areal Flood Advisory	CHS	Bryan, Chatham	2 hr
Sep 21, 9:34 AM EDT	Flash Flood Warning	CHS	Chatham	116 min
Sep 21, 9:39 AM EDT	Severe Thunderstorm Warning	CHS	Chatham	44 min
Sep 21, 10:10 AM EDT	Special Marine Warning	CHS		65 min

Nearby

Flash Flood Warnings in Georgia, 2007 Every flash flood warning in 2007

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.