Alert archive / North Carolina / Flash Flood Warnings in 2012

Flash Flood Warning 34, NWS Raleigh, NC

August 22, 2012Davidson County, North Carolina

NWS Raleigh, NC issued this flash flood warning at Aug 22, 2012, 7:40 PM EDT for Davidson 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: Aug 22, 2012, 7:40 PM EDT (23:40 UTC)
Expired: Aug 22, 2012, 10:10 PM EDT
In force: 3 hr
Issued by: NWS Raleigh, NC
Area: Storm-based polygon
Flood severity: None

County Davidson County, NC

The radar

The Roanoke radar (KFCX), 135 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.

What was reported inside it

Time	Report	Where	Remark
Aug 22, 8:36 PM EDT	HEAVY RAIN 1.73	2 Nne Linwood, NC	4 TO 5 INCHES OF WATER ON THE ROAD WAS REPORTED AT BURKHART RD AND BECKS CHURCH RD AT 836 PM. HAD RECEEDED 10 MIN LATER.

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 12:00Z, 11.7 hours before the alert went out and 51 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: 827 J/kg
Mixed-layer CIN: -16 J/kg
Mixed-layer LCL: 732 m above ground
0-6 km bulk shear: 35 kt
0-1 km storm-relative helicity: 5 m²/s²
0-3 km storm-relative helicity: 40 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.2

Open this sounding in Storm Lab

The text

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

818 
WGUS52 KRAH 222340
FFWRAH
NCC057-230245-
/O.NEW.KRAH.FF.W.0034.120822T2340Z-120823T0245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE RALEIGH NC
740 PM EDT WED AUG 22 2012

THE NATIONAL WEATHER SERVICE IN RALEIGH HAS ISSUED A

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

* UNTIL 1045 PM EDT

* AT 736 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
  SLOW MOVING THUNDERSTORMS PRODUCING FLOODING OVER DAVIDSON         
  COUNTY. DOPPLER RADAR ESTIMATED THAT 3 TO 4 INCHES OF RAIN HAS     
  FALLEN OVER LEXINGTON.

* LOCATIONS THREATENED WITH FLOODING INCLUDE THOMASVILLE...LEXINGTON
  AND LINWOOD.

AN ADDITIONAL 1 TO 2 INCHES OF RAINFALL ARE STILL POSSIBLE RESULTING 
IN ADDITIONAL FLOODING.

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 3584 8048 3584 8043 3586 8042 3585 8039
      3589 8042 3589 8037 3598 8040 3601 8005
      3575 8006 3568 8033 3569 8034 3570 8033
      3572 8034 3572 8042 3574 8046

$$

10

2 follow-up statements

793 
WGUS72 KRAH 230057
FFSRAH

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE RALEIGH NC
857 PM EDT WED AUG 22 2012

NCC057-230245-
/O.CON.KRAH.FF.W.0034.000000T0000Z-120823T0245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
DAVIDSON NC-
857 PM EDT WED AUG 22 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1045 PM EDT FOR
NORTHERN DAVIDSON COUNTY...

AT 851 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE SLOW MOVING THUNDERSTORMS PRODUCING FLOODING OVER NORTHERN 
DAVIDSON COUNTY. DOPPLER RADAR ESTIMATED THAT 3 TO 5 INCHES OF RAIN 
HAS FALLEN OVER LEXINGTON. ALTHOUGH THE HEAVIEST RAIN HAS 
ENDED...SOME LIGHT TO MODERATE RAIN CONTINUES TO FALL.

LOCATIONS THREATENED BY FLOODING INCLUDE BUT ARE NOT LIMITED TO 
LEXINGTON AND THOMASVILLE.

HIGH WATER WAS REPORTED ON MANY ROADS IN THE LEXINGTON AREA...AND 
NUMEROUS AUTOMOBILE ACCIDENTS WERE REPORTED. 

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. USE CAUTION 
WHILE DRIVING TO REDUCE THE RISK OF HYDROPLANING.

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. 

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 3584 8043 3586 8042 3585 8039 3589 8042
      3589 8037 3596 8038 3598 8040 3601 8005
      3575 8006 3568 8033 3572 8034 3572 8042
      3574 8046 3584 8048

$$

10

742 
WGUS72 KRAH 230210
FFSRAH

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE RALEIGH NC
1010 PM EDT WED AUG 22 2012

NCC057-230216-
/O.CAN.KRAH.FF.W.0034.000000T0000Z-120823T0245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
DAVIDSON NC-
1010 PM EDT WED AUG 22 2012

...THE FLASH FLOOD WARNING HAS BEEN CANCELLED FOR NORTHERN DAVIDSON
COUNTY...

AT 1003 PM EDT...THE SLOW MOVING THUNDERSTORM THAT WAS PRODUCING 
FLOODING OVER NORTHERN DAVIDSON COUNTY HAS DISSIPATED AND THE 
FLOODING THREAT HAS ENDED. DOPPLER RADAR ESTIMATED THAT OVER 2 
INCHES OF RAIN HAS FALLEN OVER LEXINGTON.

THE DAVIDSON COUNTY AIRPORT IN LEXINGTON HAD REPORTED 1.73 INCHES OF 
RAIN. 

LAT...LON 3584 8043 3586 8042 3585 8039 3589 8042
      3589 8037 3596 8038 3598 8040 3601 8005
      3575 8006 3568 8033 3572 8034 3572 8042
      3574 8046 3584 8048

$$

10

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 22, 12:52 AM EDT	Special Weather Statement	RAH	Davie	63 min
Aug 22, 12:29 PM EDT	Special Weather Statement	RAH	Randolph	46 min
Aug 22, 12:49 PM EDT	Special Weather Statement	RAH	Montgomery	41 min
Aug 22, 1:03 PM EDT	Special Weather Statement	RAH	Montgomery	42 min
Aug 22, 1:51 PM EDT	Areal Flood Advisory	RAH	Lee, Moore	2 hr
Aug 22, 2:02 PM EDT	Areal Flood Advisory	RAH	Wake	118 min
Aug 22, 4:53 PM EDT	Areal Flood Advisory	RAH	Forsyth	110 min
Aug 22, 6:06 PM EDT	Special Weather Statement	RAH	Davidson	54 min
Aug 22, 6:20 PM EDT	Special Weather Statement	RAH	Guilford	40 min
Aug 22, 6:29 PM EDT	Areal Flood Advisory	RAH	Guilford	3 hr
Aug 22, 6:51 PM EDT	Flash Flood Warning	RAH	Guilford	84 min
Aug 22, 7:06 PM EDT	Areal Flood Advisory	RAH	Davidson	3 hr

Nearby

Flash Flood Warnings in North Carolina, 2012 Every flash flood warning in 2012

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.