Alert archive / North Carolina / Flash Flood Warnings in 2011

Flash Flood Warning 18, NWS Raleigh, NC

June 28, 2011Davidson County, Forsyth County, Guilford County, North Carolina

NWS Raleigh, NC issued this flash flood warning at Jun 28, 2011, 9:38 PM EDT for Davidson County, Forsyth County, Guilford County, North Carolina. It was in force for 86 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Jun 28, 2011, 9:38 PM EDT (01:38 UTC)
Expired: Jun 28, 2011, 11:04 PM EDT
In force: 86 min
Issued by: NWS Raleigh, NC
Area: Storm-based polygon
Flood severity: None

Counties Davidson County, NC, Forsyth County, NC, Guilford County, NC

The radar

The Roanoke radar (KFCX), 123 km from the middle of the area, began a volume at 01:39 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

Roanoke, VA (KRNK), launched 00:00Z, 1.6 hours before the alert went out and 158 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: 628 J/kg
Mixed-layer CIN: -23 J/kg
Mixed-layer LCL: 643 m above ground
0-6 km bulk shear: 25 kt
0-1 km storm-relative helicity: -47 m²/s²
0-3 km storm-relative helicity: -8 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.

494 
WGUS52 KRAH 290138
FFWRAH
NCC057-067-081-290430-
/O.NEW.KRAH.FF.W.0018.110629T0138Z-110629T0430Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE RALEIGH NC
938 PM EDT TUE JUN 28 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
  GUILFORD COUNTY IN CENTRAL NORTH CAROLINA

* UNTIL 1230 AM EDT

* AT 929 PM EDT...LOCAL LAW ENFORCEMENT REPORTED THUNDERSTORMS WITH
  VERY HEAVY RAIN PRODUCING FLOODING OVER WESTERN                    
  GUILFORD...FORSYTH AND DAVIDSON COUNTIES. DOPPLER RADAR            
  ESTIMATED THAT 6 INCHES OF RAIN HAS FALLEN OVER                    
  GUILFORD...FORSYTH...AND DAVIDSON COUNTIES.

* LOCATIONS THREATENED WITH FLOODING INCLUDE WINSTON-SALEM...
  THOMASVILLE...LINWOOD...LEXINGTON...KERNERSVILLE...HUNTSVILLE...   
  HIGH POINT...GREENSBORO...CLEMMONS AND BELEWS CREEK. EMERGENCY     
  MANAGERS HAVE REPORTED ONGOING FLOODING ACROSS GUILFORD COUNTY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

NEVER DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE ROAD.
AS LITTLE AS 6 INCHES OF WATER CAN CAUSE YOU TO LOSE CONTROL OF YOUR
VEHICLE. TWO FEET OF RUSHING WATER CAN CARRY AWAY MOST VEHICLES
INCLUDING SPORT UTILITY VEHICLES AND PICKUP TRUCKS. 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.

PLEASE REPORT FLOODING TO THE NATIONAL WEATHER SERVICE BY CALLING...
1...8 7 7...6 3 3...6 7 7 2 OR NOTIFY YOUR LOCAL LAW ENFORCEMENT
AGENCY.

&&

LAT...LON 3608 8052 3614 8044 3626 8046 3626 8002
      3618 8002 3618 7967 3591 7967 3592 8004
      3551 8006 3550 8019 3568 8034 3571 8033
      3573 8045 3579 8048 3584 8049 3585 8039
      3589 8042 3590 8038 3589 8037 3601 8042

$$

ELLIS

1 follow-up statement

890 
WGUS72 KRAH 290304
FFSRAH

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE RALEIGH NC
1104 PM EDT TUE JUN 28 2011

NCC057-067-081-290312-
/O.CAN.KRAH.FF.W.0018.000000T0000Z-110629T0430Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
DAVIDSON NC-FORSYTH NC-GUILFORD NC-
1104 PM EDT TUE JUN 28 2011

...THE FLASH FLOOD WARNING HAS BEEN CANCELLED FOR WESTERN GUILFORD...
FORSYTH AND DAVIDSON COUNTIES...

AT 1100 PM EDT...RAIN WAS STILL FALLING IN THE TRIAD BUT RAIN RATES 
HAVE DETERIORATED AND ANY THREAT FOR NEW FLOODING HAS DIMINISHED 
SIGNIFICANTLY. LIGHT RAIN WILL STILL CONTINUE TO FALL OVER THE AREA 
DURING THE NEXT FEW HOURS AND CAUTION SHOULD BE 
EXERCISED...ESPECIALLY IN AREAS THAT WERE EFFECTED BY PRIOR FLOODING.

MULTIPLE REPORTS OF FLOODING WERE OBSERVED ACROSS THE TRIAD.

LAT...LON 3608 8052 3614 8044 3626 8046 3626 8002
      3618 8002 3618 7967 3591 7967 3592 8004
      3551 8006 3550 8019 3568 8034 3571 8033
      3573 8045 3579 8048 3584 8049 3585 8039
      3589 8042 3590 8038 3589 8037 3601 8042

$$

ELLIS

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 28, 8:03 PM EDT	Flash Flood Warning	RAH	Alamance, Guilford	3 hr
Jun 28, 8:06 PM EDT	Special Weather Statement	RAH	Davidson, Guilford, Randolph	54 min
Jun 28, 9:02 PM EDT	Special Weather Statement	RAH	Davidson	58 min

Nearby

Flash Flood Warnings in North Carolina, 2011 Every 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.