Alert archive / North Carolina / Flash Flood Warnings in 2011

Flash Flood Warning 22, NWS Raleigh, NC

July 8, 2011Davidson County, Forsyth County, North Carolina

NWS Raleigh, NC issued this flash flood warning at Jul 8, 2011, 9:33 PM EDT for Davidson County, Forsyth County, North Carolina. It was in force for 3 hr. 5 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
Jul 8, 2011, 9:33 PM EDT (01:33 UTC)
Expired
Jul 9, 2011, 12:30 AM EDT
In force
3 hr
Issued by
NWS Raleigh, NC
Area
Storm-based polygon
Flood severity
None

Counties Davidson County, NC, Forsyth County, NC

The radar

The Roanoke radar (KFCX), 119 km from the middle of the area, began a volume at 01:33 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
Jul 8, 10:10 PM EDTFLASH FLOOD4 E Clemmons, NCROAD CLOSED DUE TO FLOODING AT GRIFFITH RD AND WEST CLEMMONSVILLE RD.
Jul 8, 11:45 PM EDTFLASH FLOOD2 Ne Welcome, NCOLD MOUNTAIN ROAD CLOSED NORTH OF LEXINGTON DUE TO FLASH FLOODING 2-3 FEET OF WATER CROSSING ROAD.
Jul 8, 11:45 PM EDTFLASH FLOOD2 Nne Lexington, NCFLASH FLOODING ON MAIN STREET IN LEXINGTON. SEVERAL INTERSECTIONS CLOSED.
Jul 8, 11:45 PM EDTFLASH FLOODLexington, NCFLASH FLOODING HAS CLOSED BENLEE ROAD IN LEXINGTON.
Jul 9, 12:40 AM EDTFLASH FLOODGordontown, NCFIRE DEPARTMENT REPORTED NEW CUT ROAD CLOSED DUE TO FLOODING.

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

The nearest sounding before it

Greensboro/Hi Pt, NC (KGSO), launched 00:00Z, 1.6 hours before the alert went out and 44 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, Greensboro/Hi Pt, NC at 00:00Z on 2011-07-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 884 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, Greensboro/Hi Pt, NC at 00:00Z on 2011-07-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 112 square meters per square second.193958Sfc1 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
884 J/kg
Mixed-layer CIN
-56 J/kg
Mixed-layer LCL
1019 m above ground
0-6 km bulk shear
24 kt
0-1 km storm-relative helicity
112 m²/s²
0-3 km storm-relative helicity
140 m²/s²
Significant tornado parameter
0.3
Supercell composite
2.2

Open this sounding in Storm Lab

The text

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

856 
WGUS52 KRAH 090133
FFWRAH
NCC057-067-090430-
/O.NEW.KRAH.FF.W.0022.110709T0133Z-110709T0430Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE RALEIGH NC
933 PM EDT FRI JUL 8 2011

THE NATIONAL WEATHER SERVICE IN RALEIGH HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  DAVIDSON COUNTY IN CENTRAL NORTH CAROLINA
  FORSYTH COUNTY IN CENTRAL NORTH CAROLINA

* UNTIL 1230 AM EDT

* AT 931 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  THUNDERSTORMS WITH VERY HEAVY RAIN PRODUCING FLOODING OVER FORSYTH 
AND NORTHERN DAVIDSON COUNTIES. RAINFALL RATES IN EXCESS OF 3 INCHES 
PER HOUR WILL PRODUCE FLASH FLOODING. 

* LOCATIONS THREATENED WITH FLOODING INCLUDE WINSTON-SALEM...
  THOMASVILLE...LINWOOD...LEXINGTON...KERNERSVILLE...CLEMMONS AND
  BELEWS CREEK.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

NEVER DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE ROAD. 
TURN AROUND...DONT DROWN.

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE
DANGERS OF FLOODS AND FLASH FLOODS. IF FLASH FLOODING IS OBSERVED ACT
QUICKLY. MOVE UP TO HIGHER GROUND TO ESCAPE FLOOD WATERS. DO NOT STAY
IN AREAS SUBJECT TO FLOODING WHEN WATER BEGINS RISING.

&&

LAT...LON 3585 8039 3589 8042 3590 8039 3589 8037
      3596 8038 3599 8043 3601 8042 3606 8047
      3605 8048 3612 8047 3614 8044 3626 8046
      3626 8004 3626 8003 3566 8006 3568 8034
      3572 8033 3573 8045 3584 8049

$$

BADGETT
2 follow-up statements
483 
WGUS72 KRAH 090218
FFSRAH

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE RALEIGH NC
1018 PM EDT FRI JUL 8 2011

NCC057-067-090430-
/O.CON.KRAH.FF.W.0022.000000T0000Z-110709T0430Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
DAVIDSON NC-FORSYTH NC-
1018 PM EDT FRI JUL 8 2011

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1230 AM EDT FOR
FORSYTH AND DAVIDSON COUNTIES...

AT 1017 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO 
INDICATE THUNDERSTORMS THAT WERE CONTINUOUSLY MOVING OVER THE SAME 
AREAS. THIS TRAINING OF THE STORMS HAS ALREADY PRODUCED 2 TO LOCALLY 
5 INCHES OF RAIN ACROSS PORTIONS OF WESTERN AND NORTHERN DAVIDSON 
COUNTY INTO CENTRAL FORSYTH COUNTY. AN ADDITIONAL 1 TO 2 INCHES OF 
RAIN MAY FALL FROM WEST END TO ARCADIA TO WINSTON-SALEM BEFORE THE 
STORMS END. 

THIS WILL PRODUCE AN EXTREMELY DANGEROUS NIGHTTIME FLOODING EPISODE 
ESPECIALLY FROM THE YADKIN RIVER TO LINWOOD NORTHEAST TO MIDWAY... 
ARCADIA... AND WINSTON-SALEM. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

EXCESSIVE RUNOFF FROM THE HEAVY RAIN WILL CAUSE FLASH FLOODING. 
DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE WATER COVERS THE ROAD. 

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE 
DANGERS OF FLOODING. MOVE UP TO HIGHER GROUND TO ESCAPE FLOOD 
WATERS. DO NOT STAY IN AREAS SUBJECT TO FLOODING WHEN WATER BEGINS 
RISING.

&&

LAT...LON 3585 8039 3589 8042 3590 8039 3589 8037
      3596 8038 3599 8043 3601 8042 3606 8047
      3605 8048 3612 8047 3614 8044 3626 8046
      3626 8004 3626 8003 3566 8006 3568 8034
      3572 8033 3573 8045 3584 8049

$$

BADGETT
112 
WGUS72 KRAH 090339
FFSRAH

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE RALEIGH NC
1139 PM EDT FRI JUL 8 2011

NCC057-067-090430-
/O.CON.KRAH.FF.W.0022.000000T0000Z-110709T0430Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
DAVIDSON NC-FORSYTH NC-
1139 PM EDT FRI JUL 8 2011

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1230 AM EDT FOR
FORSYTH AND DAVIDSON COUNTIES...

AT 1135 PM EDT...THUNDERSTORMS WITH VERY HEAVY RAIN CONTINUE TO 
AFFECT DAVIDSON COUNTY. NUMEROUS THUNDERSTORMS HAVE PRODUCED LOCALLY 
UP TO 5 INCHES OF RAIN THUS FAR. AN ADDITIONAL INCH MAY FALL BEFORE 
THE RAIN TAPERS OFF. 

SEVERAL ROADS HAVE BEEN FLOODED AND AT LEAST ONE ROAD CLOSED AT 
GRIFFITH AND WEST CLEMMONSVILLE IN WINSTON-SALEM DUE TO FLOODING. 

LOCATIONS THREATENED BY FLOODING INCLUDE BUT ARE NOT LIMITED TO 
RURAL DAVIDSON AND FORSYTH COUNTIES INCLUDING US-52 AND INTERSTATE 
85 THROUGH THE REGION. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

DANGEROUS FLASH FLOODING IS OCCURRING ACROSS THE AREA. 

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE
DANGERS OF FLOODING. IF FLASH FLOODING IS OBSERVED ACT QUICKLY. MOVE
UP TO HIGHER GROUND TO ESCAPE FLOOD WATERS. DO NOT STAY IN AREAS
SUBJECT TO FLOODING WHEN WATER BEGINS RISING.

&&

LAT...LON 3585 8039 3589 8042 3590 8039 3589 8037
      3596 8038 3599 8043 3601 8042 3606 8047
      3605 8048 3612 8047 3614 8044 3626 8046
      3626 8004 3626 8003 3566 8006 3568 8034
      3572 8033 3573 8045 3584 8049

$$

BADGETT

The office that day

Everything else NWS Raleigh, NC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 8, 8:28 PM EDTAreal Flood AdvisoryRAHDurham, Orange52 min
Jul 8, 8:31 PM EDTSpecial Weather StatementRAHDurham, Orange59 min
Jul 8, 8:40 PM EDTSpecial Weather StatementRAHDavidson, Forsyth, Guilford80 min
Jul 8, 9:05 PM EDTAreal Flood AdvisoryRAHDavidson, Forsyth, Guilford, Randolph3 hr
Jul 8, 9:25 PM EDTSevere Thunderstorm WarningRAHDavidson, Forsyth65 min
Jul 8, 9:28 PM EDTSevere Thunderstorm WarningRAHGuilford, Randolph60 min
Jul 8, 9:37 PM EDTFlash Flood WarningRAHGuilford, Randolph3 hr
Jul 9, 12:19 AM EDTFlash Flood WarningRAHDavidson, Forsyth, Guilford, Randolph3 hr
Jul 9, 5:16 PM EDTSpecial Weather StatementRAHScotland59 min

Nearby

Flash Flood Warnings in North Carolina, 2011Every flash flood warning in 2011

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.