Alert archive / Georgia / Flash Flood Watches in 2013

Flash Flood Watch 3, NWS Charleston, SC

July 11, 20135 counties in South Carolina; 8 counties in Georgia

NWS Charleston, SC issued this flash flood watch at Jul 11, 2013, 7:37 PM EDT for 5 counties in South Carolina; 8 counties in Georgia. It was in force for 71 hr.

The area

The counties it named.

The facts

Issued: Jul 11, 2013, 7:37 PM EDT (23:37 UTC)
Expired: Jul 14, 2013, 6:47 PM EDT
In force: 71 hr
Issued by: NWS Charleston, SC
Flood severity: None

Counties Bulloch County, GA, Candler County, GA, Effingham County, GA, Evans County, GA, Jenkins County, GA, Long County, GA, Screven County, GA, Tattnall County, GA, Allendale County, SC, Berkeley County, SC, Colleton County, SC, Dorchester County, SC, Hampton County, SC

The radar

The Charleston,SC radar (KCLX), 33 km from the middle of the area, began a volume at 23:39 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 12:00Z, 11.6 hours before the alert went out and 134 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: 902 J/kg
Mixed-layer CIN: -3 J/kg
Mixed-layer LCL: 692 m above ground
0-6 km bulk shear: 3 kt
0-1 km storm-relative helicity: -58 m²/s²
0-3 km storm-relative helicity: -28 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 flash flood watch 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 flash flood watch went out at Jul 11, 7:22 PM EDT, 15 minutes earlier.

Area forecast discussion, Jul 11, 7:22 PM EDT, 15 minutes before

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Hazardous weather outlook, Jul 11, 3:35 PM EDT, 4 hours 2 minutes before

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In the hours before

Local storm report, Jul 11, 2:43 PM EDT, 4 hours 54 minutes before

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Special weather statement, Jul 11, 3:48 PM EDT, 3 hours 49 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHARLESTON SC
348 PM EDT THU JUL 11 2013

SCZ045-112030-
INLAND BERKELEY-
348 PM EDT THU JUL 11 2013

...MARINERS ON LAKE MOULTRIE SHOULD SEEK SAFE HARBOR...

AT 346 PM EDT...NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED A
SHOWERS AND THUNDERSTORMS DEVELOPING AROUND LAKE MOULTRIE. THESE
STORMS WILL CONTINUE TO INTENSIFY AND BECOME MORE SCATTERED ACROSS
THE LAKE THROUGH 430 PM.

PREPARE NOW FOR THE FOLLOWING HAZARDS...
GUSTY WINDS OF 25 TO 30 KNOTS...
CLOUD TO WATER LIGHTNING...
HEAVY RAINFALL PRODUCING VISIBILITIES LESS THAN 1 NM...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THESE STORMS ARE EXPECTED TO IMPACT LAKE MOULTRIE. BOATERS SHOULD
SEEK SAFE HARBOR IMMEDIATELY. IF CAUGHT ON THE OPEN WATERS...STAY AS
LOW AS POSSIBLE AND WEAR A PERSONAL FLOATATION DEVICE. SWIMMERS
SHOULD GET OUT OF THE WATER AND INTO A STURDY BUILDING. REMEMBER...IF
YOU CAN HEAR THUNDER YOU ARE AT RISK OF BEING STRUCK BY LIGHTNING.

&&

LAT...LON 3333 8014 3339 8008 3339 8000 3332 7997
      3325 7999 3320 8004 3326 8010 3329 8015
TIME...MOT...LOC 1947Z 220DEG 4KT 3324 8005

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 10, 8:12 PM EDT	Special Weather Statement	CHS	Hampton	33 min
Jul 11, 11:11 AM EDT	Special Marine Warning	CHS		2 hr
Jul 11, 3:20 PM EDT	Areal Flood Advisory	CHS	Charleston, Colleton, Dorchester	55 min
Jul 11, 3:48 PM EDT	Special Weather Statement	CHS	Berkeley	42 min
Jul 11, 4:13 PM EDT	Areal Flood Advisory	CHS	Berkeley, Dorchester	92 min
Jul 11, 3:45 PM EDT	Areal Flood Advisory	CHS	Bryan, Liberty	60 min
Jul 11, 7:24 PM EDT	Areal Flood Advisory	CHS	Liberty, Long	96 min

Nearby

Flash Flood Watches in Georgia, 2013 Flash Flood Watches in South Carolina, 2013 Every flash flood watch in 2013

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.