Alert archive / South Carolina / Flash Flood Warnings in 2015

Flash Flood Warning 13, NWS Charleston, SC

October 1, 2015Charleston County, South Carolina

NWS Charleston, SC issued this flash flood warning at Oct 1, 2015, 1:39 PM EDT for Charleston County, South Carolina. It was in force for 6 hr. 9 reports 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
Oct 1, 2015, 1:39 PM EDT (17:39 UTC)
Expired
Oct 1, 2015, 7:30 PM EDT
In force
6 hr
Issued by
NWS Charleston, SC
Area
Storm-based polygon
Flood severity
None

County Charleston County, SC

The radar

The Charleston,SC radar (KCLX), 104 km from the middle of the area, began a volume at 17:42 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

TimeReportWhereRemark
Oct 1, 1:54 PM EDTFLASH FLOOD1 N Charleston, SCLAW ENFORCEMENT REPORTS NASSAU ST AT COOPER ST CLOSED DUE TO WATER COVERING THE ROADWAY.
Oct 1, 1:54 PM EDTFLASH FLOOD1 Wnw Charleston, SCLAW ENFORCEMENT REPORTS HAGOOD AVE AT FISHBURNE ST CLOSED DUE TO WATER COVERING THE ROADWAY.
Oct 1, 1:54 PM EDTFLASH FLOOD1 Wnw Charleston, SCLAW ENFORCEMENT REPORTS LINE ST AT HAGOOD AVE CLOSED DUE TO WATER COVERING THE ROADWAY.
Oct 1, 2:22 PM EDTFLASH FLOOD1 Nnw Charleston, SCLAW ENFORCEMENT REPORTS CROSSTOWN EXPRESSWAY CLOSED DUE TO WATER COVERING THE ROADWAY.
Oct 1, 2:25 PM EDTFLASH FLOOD1 Wnw Charleston, SCLAW ENFORCEMENT REPORTS PRESIDENT ST AT CANNON ST CLOSED DUE TO WATER COVERING THE ROADWAY.
Oct 1, 2:44 PM EDTFLASH FLOODCharleston, SCLAW ENFORCEMENT REPORTS S MARKET ST CLOSED AT MEETING ST DUE TO WATER COVERING THE ROADWAY.
Oct 1, 4:30 PM EDTHEAVY RAIN 2.11Charleston, SCNEW DAILY RAINFALL RECORD FOR DOWNTOWN CHARLESTON SC.
Oct 1, 4:35 PM EDTHEAVY RAIN 2.452 E Charles Towne Landi, SC
Oct 1, 4:45 PM EDTHEAVY RAIN 2.891 Wnw Charleston, SCRAIN BEGAN AT 1245 PM

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, 5.7 hours before the alert went out and 13 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 12:00Z on 2015-10-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 594 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 12:00Z on 2015-10-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 11 square meters per square second.19395878Sfc1 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
594 J/kg
Mixed-layer CIN
-25 J/kg
Mixed-layer LCL
646 m above ground
0-6 km bulk shear
37 kt
0-1 km storm-relative helicity
11 m²/s²
0-3 km storm-relative helicity
30 m²/s²
Significant tornado parameter
0.1
Supercell composite
0.6

Open this sounding in Storm Lab

The text

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

491 
WGUS52 KCHS 011739
FFWCHS
SCC019-012330-
/O.NEW.KCHS.FF.W.0013.151001T1739Z-151001T2330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE CHARLESTON SC
139 PM EDT THU OCT 1 2015

THE NATIONAL WEATHER SERVICE IN CHARLESTON HAS ISSUED A

* FLASH FLOOD WARNING FOR PORTIONS OF...
  CHARLESTON COUNTY IN SOUTHEASTERN SOUTH CAROLINA...

* UNTIL 730 PM EDT

* AT 136 PM EDT...DOPPLER RADAR INDICATED TORRENTIAL RAINFALL 
  CONTINUING TO MOVE ACROSS DOWNTOWN CHARLESTON AND THE CHARLESTON 
  NECK. RAIN GAGES INDICATE AS MUCH AS 2 INCHES OF RAIN HAS ALREADY 
  OCCURRED ACROSS PORTIONS OF DOWNTOWN. WITH THE TIDES CONTINUING TO 
  RUN HIGHER THAN NORMAL...RAINFALL WILL BE VERY SLOW TO DRAIN.

NUMEROUS STREETS ARE EXPECTED TO FLOOD OR ALREADY FLOODING AS A   
RESULT OF THIS HEAVY RAINFALL. MOTORISTS ARE URGED NOT TO VENTURE 
INTO DOWNTOWN CHARLESTON UNLESS ABSOLUTELY NECESSARY. ADDITIONAL 
ROAD FLOODING IS LIKELY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IF ROAD FLOODING IS ENCOUNTERED...FIND AN ALTERNATE ROUTE. ONLY ONE 
FOOT OF WATER IS ENOUGH TO STALL A VEHICLE AND TWO FEET WILL CAUSE 
ONE TO FLOAT.

&&

LAT...LON 3277 7992 3277 7995 3279 7997 3282 7996
      3284 7998 3285 7994 3282 7993 3280 7993
      3278 7992 3278 7991

$$

JRL
3 follow-up statements
988 
WGUS72 KCHS 011855
FFSCHS

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE CHARLESTON SC
255 PM EDT THU OCT 1 2015

SCC019-012330-
/O.CON.KCHS.FF.W.0013.000000T0000Z-151001T2330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
CHARLESTON SC-
255 PM EDT THU OCT 1 2015

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 730 PM EDT FOR 
CENTRAL CHARLESTON COUNTY...

AT 244 PM EDT...DOPPLER RADAR INDICATED THE HEAVIEST RAINFALL HAS 
SHIFTED OUT OF DOWNTOWN CHARLESTON. HOWEVER...ADDITIONAL MODERATE TO 
HEAVY RAIN IS BEGINNING TO MOVE BACK INTO THE CHARLESTON AREA. 
EXISTING FLOODING ISSUES MAY NOT WORSEN...BUT ARE LIKELY TO CONTINUE 
THROUGH MID TO LATE AFTERNOON DUE TO ABOVE NORMAL TIDES AND 
SIGNIFICANT ACCUMULATED WATER FROM EARLIER RAIN.

MOTORISTS ARE URGED TO AVOID DRIVING IN DOWNTOWN CHARLESTON UNLESS 
ABSOLUTELY NECESSARY. NUMEROUS ROADS REMAIN CLOSED OR 
IMPASSABLE INCLUDING PRIMARY ARTERIES.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IF ROAD FLOODING IS ENCOUNTERED...FIND AN ALTERNATE ROUTE. ONLY ONE 
FOOT OF WATER IS ENOUGH TO STALL A VEHICLE AND TWO FEET WILL CAUSE 
ONE TO FLOAT.

LAT...LON 3277 7992 3277 7995 3279 7997 3282 7996
      3284 7998 3285 7994 3282 7993 3280 7993
      3278 7992 3278 7991

$$

JRL
816 
WGUS72 KCHS 012058
FFSCHS

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE CHARLESTON SC
458 PM EDT THU OCT 1 2015

SCC019-012330-
/O.CON.KCHS.FF.W.0013.000000T0000Z-151001T2330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
CHARLESTON SC-
458 PM EDT THU OCT 1 2015

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 730 PM EDT FOR
CHARLESTON COUNTY...

AT 453 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR SHOWED AN 
AREA OF LIGHT TO MODERATE RAIN CONTINUING OVER DOWNTOWN CHARLESTON. 
AS TIDE LEVELS HAVE CONTINUED TO FALL AND MOST OF THE RECENT 
RAINFALL HAS NOT BEEN HEAVY...ROAD CONDITIONS APPEAR TO BE 
IMPROVING. THE LATEST REPORTS SHOW THAT THE CROSSTOWN EXPRESSWAY HAS 
BEEN REOPENED AND OTHER STREETS ARE SHOWING SIGNS OF IMPROVEMENT.

ADDITIONAL RAINFALL CONTINUES TO MOVE ONSHORE HOWEVER IT IS UNCLEAR 
WHETHER THE RAINFALL WILL BECOME HEAVY OVER DOWNTOWN CHARLESTON. 
RESIDENTS AND VISITORS ARE URGED TO CONTINUE TO AVOID TRAVEL IN 
DOWNTOWN CHARLESTON IF AT ALL POSSIBLE. NUMEROUS STREETS ARE STILL 
FLOODED AND MANY ROUTES REMAIN CUT OFF.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IF ROAD FLOODING IS ENCOUNTERED...FIND AN ALTERNATE ROUTE. ONLY ONE 
FOOT OF WATER IS ENOUGH TO STALL A VEHICLE AND TWO FEET WILL CAUSE 
ONE TO FLOAT.

LAT...LON 3277 7992 3277 7995 3279 7997 3282 7996
      3284 7998 3285 7994 3282 7993 3280 7993
      3278 7992 3278 7991

$$

JRL
461 
WGUS72 KCHS 012325
FFSCHS

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE CHARLESTON SC
725 PM EDT THU OCT 1 2015

SCC019-012330-
/O.EXP.KCHS.FF.W.0013.000000T0000Z-151001T2330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
CHARLESTON SC-
725 PM EDT THU OCT 1 2015

...THE FLASH FLOOD WARNING FOR CHARLESTON COUNTY WILL EXPIRE AT 730
PM EDT...

THE HEAVIEST RAINFALL HAS MOVED OUT OF DOWNTOWN CHARLESTON AND LOW 
TIDE OCCURRED AT 530 PM. SOME STREETS REMAIN CLOSED DUE TO FLOODING 
IN DOWNTOWN CHARLESTON...HOWEVER ADDITIONAL ROAD CLOSURES ARE NOT 
ANTICIPATED THROUGH 9 PM. ADDITIONAL HEAVY RAINFALL MAY MOVE INTO 
THE AREA LATER THIS EVENING OR OVERNIGHT...COINCIDENT WITH ANOTHER 
ABOVE NORMAL HIGH TIDE. IN THIS EVENT...ANOTHER FLASH FLOOD WARNING 
MAY BE REQUIRED.

ALTHOUGH THE HEAVY RAINFALL HAS TEMPORARILY ENDED...CONDITIONS WILL 
LIKELY REMAIN TREACHEROUS FOR MOTORISTS THROUGH TONIGHT. PEOPLE ARE 
URGED TO AVOID UNNECESSARY TRAVEL IN DOWNTOWN CHARLESTON TONIGHT.

LAT...LON 3277 7992 3277 7995 3279 7997 3282 7996
      3284 7998 3285 7994 3282 7993 3280 7993
      3278 7992 3278 7991

$$

JRL

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 30, 9:43 PM EDTCoastal Flood WatchCHS9 hr
Oct 1, 12:33 AM EDTSmall Craft AdvisoryCHS7 days
Oct 1, 4:15 AM EDTFlash Flood WatchCHSAllendale, Berkeley, Colleton, Dorchester, Hampton5 days
Oct 1, 4:32 AM EDTCoastal Flood AdvisoryCHS8 hr
Oct 1, 12:45 PM EDTAreal Flood AdvisoryCHSCharleston60 min
Oct 1, 2:02 PM EDTAreal Flood AdvisoryCHSBeaufort58 min
Oct 1, 3:11 PM EDTAreal Flood AdvisoryCHSBeaufort94 min
Oct 1, 4:09 PM EDTCoastal Flood AdvisoryCHS10 hr
Oct 1, 4:09 PM EDTRip Current StatementCHS3 days

Nearby

Flash Flood Warnings in South Carolina, 2015Every flash flood warning in 2015

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.