Alert archive / North Carolina / Flash Flood Warnings in 2011

Flash Flood Warning 17, NWS Raleigh, NC

June 28, 2011Alamance County, Guilford County, North Carolina

NWS Raleigh, NC issued this flash flood warning at Jun 28, 2011, 8:03 PM EDT for Alamance County, Guilford County, North Carolina. It was in force for 3 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: Jun 28, 2011, 8:03 PM EDT (00:03 UTC)
Expired: Jun 28, 2011, 11:00 PM EDT
In force: 3 hr
Issued by: NWS Raleigh, NC
Area: Storm-based polygon
Flood severity: None

Counties Alamance County, NC, Guilford County, NC

The radar

The Raleigh/Durham radar (KRAX), 109 km from the middle of the area, began a volume at 00:03 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
Jun 28, 8:45 PM EDT	FLASH FLOOD	Burlington, NC	MULTIPLE WATER RESCUES ONGOING IN BURLINGTON

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

The nearest sounding before it

Roanoke, VA (KRNK), launched 00:00Z, 0.1 hours before the alert went out and 127 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.

284 
WGUS52 KRAH 290003
FFWRAH
NCC001-081-290300-
/O.NEW.KRAH.FF.W.0017.110629T0003Z-110629T0300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE RALEIGH NC
803 PM EDT TUE JUN 28 2011

THE NATIONAL WEATHER SERVICE IN RALEIGH HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  ALAMANCE COUNTY IN CENTRAL NORTH CAROLINA
  GUILFORD COUNTY IN CENTRAL NORTH CAROLINA

* UNTIL 1100 PM EDT

* AT 758 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  THUNDERSTORMS WITH VERY HEAVY RAIN PRODUCING FLOODING OVER
  NORTHEASTERN GUILFORD AND ALAMANCE COUNTIES. DOPPLER RADAR         
  ESTIMATED THAT UP TO 3 INCHES OF RAIN HAS FALLEN OVER GUILFORD AND 
  ALAMANCE COUNTIES.
* LOCATIONS THREATENED WITH FLOODING INCLUDE MEBANE...MCLEANSVILLE...
  GRAHAM...ELON COLLEGE AND BURLINGTON.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

EXCESSIVE RUNOFF FROM THE HEAVY RAIN WILL CAUSE FLASH FLOODING OF
CREEKS AND STREAMS...ROADS...LOW LYING AND POOR DRAINAGE AREAS. DO
NOT DRIVE YOUR VEHICLE INTO AREAS WHERE WATER COVERS THE ROAD. MANY
ROADS AND INTERSECTIONS IN THE AREA WILL QUICKLY FLOOD. WHEN
ENCOUNTERING FLOODED ROADS 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 3625 7964 3625 7926 3590 7926 3585 7924
      3585 7954 3590 7955 3591 7970 3614 7970
      3614 8003 3626 8004

$$

ELLIS

2 follow-up statements

051 
WGUS72 KRAH 290041
FFSRAH

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

NCC001-081-290300-
/O.CON.KRAH.FF.W.0017.000000T0000Z-110629T0300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
ALAMANCE NC-GUILFORD NC-
841 PM EDT TUE JUN 28 2011

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1100 PM EDT FOR
NORTHEASTERN GUILFORD AND ALAMANCE COUNTIES...

AT 838 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE THUNDERSTORMS WITH VERY HEAVY RAIN OVER NORTHEASTERN
GUILFORD AND ALAMANCE COUNTIES. DOPPLER RADAR ESTIMATED THAT 4 INCHES
OF RAIN HAS FALLEN OVER GUILFORD AND ALAMANCE COUNTIES.

GUILFORD COUNTY OFFICIALS REPORTING THAT URBAN FLOODING IS OCCURRING 
AT THIS TIME IN MULTIPLE LOCATIONS.

LOCATIONS THREATENED BY FLOODING INCLUDE BUT ARE NOT LIMITED TO
MEBANE...MCLEANSVILLE...GRAHAM...ELON COLLEGE AND BURLINGTON

PRECAUTIONARY/PREPAREDNESS ACTIONS...

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL
CREEKS AND STREAMS...URBAN AREAS...HIGHWAYS...STREETS AND UNDERPASSES
AS WELL AS OTHER DRAINAGE AREAS AND LOW LYING SPOTS.

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.

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 3625 7964 3625 7926 3590 7926 3585 7924
      3585 7954 3590 7955 3591 7970 3614 7970
      3614 8003 3626 8004

$$

ELLIS

185 
WGUS72 KRAH 290255
FFSRAH

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE RALEIGH NC
1055 PM EDT TUE JUN 28 2011

NCC001-081-290304-
/O.EXP.KRAH.FF.W.0017.000000T0000Z-110629T0300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
ALAMANCE NC-GUILFORD NC-
1055 PM EDT TUE JUN 28 2011

...THE FLASH FLOOD WARNING WILL EXPIRE AT 1100 PM EDT FOR
NORTHEASTERN GUILFORD AND ALAMANCE COUNTIES...

AT 1050 PM EDT...LIGHT RAIN WAS STILL OCCURRING OVER GUILFORD AND 
ALAMANCE COUNTIES BUT RAIN RATES HAVE DECREASED SIGNIFICANTLY AND 
THE RISK FOR NEW FLOODING HAS LOWERED CONSIDERABLY. CAUTION SHOULD 
STILL BE EXERCISED IN AREAS WHERE WATER MAY STILL BE STANDING DUE TO 
PREVIOUS FLOODING.

MULTIPLE REPORTS OF FLOODING WERE REPORTED ACROSS GUILFORD AND 
ALAMANCE COUNTIES.

LAT...LON 3625 7964 3625 7926 3590 7926 3585 7924
      3585 7954 3590 7955 3591 7970 3614 7970
      3614 8003 3626 8004

$$

ELLIS

The office that day

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

Issued	Product	Office	Counties	Lasted
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
Jun 28, 9:38 PM EDT	Flash Flood Warning	RAH	Davidson, Forsyth, Guilford	86 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.