Alert archive / North Carolina / Flash Flood Warnings in 2012

Flash Flood Warning 22, NWS Raleigh, NC

July 28, 20124 counties in North Carolina

NWS Raleigh, NC issued this flash flood warning at Jul 28, 2012, 9:30 PM EDT for 4 counties in 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
Jul 28, 2012, 9:30 PM EDT (01:30 UTC)
Expired
Jul 29, 2012, 12:30 AM EDT
In force
3 hr
Issued by
NWS Raleigh, NC
Area
Storm-based polygon
Flood severity
None

Counties Chatham County, NC, Durham County, NC, Orange County, NC, Wake County, NC

The radar

The Raleigh/Durham radar (KRAX), 36 km from the middle of the area, began a volume at 01:34 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 28, 9:52 PM EDTFLASH FLOOD5 Sse Chapel Hill, NCCREEK FLOODED OLD FEARRINGTON ROAD... ROAD CLOSED

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, 1.5 hours before the alert went out and 101 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 2012-07-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 846 joules per kilogram.LCLEL10008507005003002001001 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 2012-07-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -21 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
846 J/kg
Mixed-layer CIN
-2 J/kg
Mixed-layer LCL
1942 m above ground
0-6 km bulk shear
40 kt
0-1 km storm-relative helicity
-21 m²/s²
0-3 km storm-relative helicity
25 m²/s²
Significant tornado parameter
-0.0
Supercell composite
-0.1

Open this sounding in Storm Lab

The text

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

209 
WGUS52 KRAH 290130
FFWRAH
NCC037-063-135-183-290430-
/O.NEW.KRAH.FF.W.0022.120729T0130Z-120729T0430Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE RALEIGH NC
930 PM EDT SAT JUL 28 2012

THE NATIONAL WEATHER SERVICE IN RALEIGH HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  EASTERN CHATHAM COUNTY IN CENTRAL NORTH CAROLINA
  DURHAM COUNTY IN CENTRAL NORTH CAROLINA
  ORANGE COUNTY IN CENTRAL NORTH CAROLINA
  WAKE COUNTY IN CENTRAL NORTH CAROLINA

* UNTIL 1230 AM EDT

* AT 929 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
THUNDERSTORMS WITH VERY HEAVY RAIN OVER RALEIGH... CHAPEL HILL... 
AND DURHAM... MOVING EAST AT 25 MPH. THESE STORMS WERE PRODUCING 
RAINFALL RATES IN EXCESS OF 3 INCHES PER HOUR. RAPID RUNOFF WILL 
CAUSE FLASH FLOODING IN URBAN AREAS. 

* LOCATIONS THREATENED WITH FLOODING INCLUDE HILLSBOROUGH...CHAPEL
  HILL...CARRBORO...DURHAM...WAKE FOREST...RDU INTERNATIONAL...
  RALEIGH...GARNER...FUQUAY-VARINA AND CARY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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 3615 7880 3609 7881 3607 7879 3607 7868
      3606 7864 3596 7847 3581 7828 3571 7847
      3553 7869 3554 7878 3558 7891 3555 7894
      3555 7897 3567 7914 3597 7927 3618 7926

$$

BADGETT
1 follow-up statement
659 
WGUS72 KRAH 290425
FFSRAH

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE RALEIGH NC
1225 AM EDT SUN JUL 29 2012

NCC037-063-135-183-290431-
/O.EXP.KRAH.FF.W.0022.000000T0000Z-120729T0430Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
CHATHAM NC-DURHAM NC-ORANGE NC-WAKE NC-
1225 AM EDT SUN JUL 29 2012

...THE FLASH FLOOD WARNING WILL EXPIRE AT 1230 AM EDT FOR WAKE...
ORANGE...DURHAM AND NORTHEASTERN CHATHAM COUNTIES...

THE THUNDERSTORMS THAT PRODUCED HEAVY RAIN AND FLOODING HAVE MOVED 
OUT OF THE WARNED AREA...AND THE FLOODING THREAT HAS ENDED.

LAW ENFORCEMENT IN CHATHAM COUNTY REPORTED FLOODING ON FARRINGTON 
POINT ROAD NEAR OLD FARRINGTON POINT ROAD.  MOTORISTS IN THE AREA 
SHOULD CONTINUE TO USE CAUTION AS THE HIGH WATER RECEDES.


LAT...LON 3615 7880 3609 7881 3607 7879 3607 7868
      3606 7864 3596 7847 3581 7828 3571 7847
      3553 7869 3554 7878 3558 7891 3555 7894
      3555 7897 3567 7914 3597 7927 3618 7926

$$

22

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 28, 8:15 PM EDTSevere Thunderstorm WarningRAHFranklin, Granville, Halifax, Vance, Warren60 min
Jul 28, 8:20 PM EDTSevere Thunderstorm WarningRAHMontgomery, Randolph55 min
Jul 28, 8:38 PM EDTSevere Thunderstorm WarningRAHAnson, Richmond50 min
Jul 28, 8:43 PM EDTSevere Thunderstorm WarningRAHChatham, Wake62 min
Jul 28, 9:11 PM EDTSevere Thunderstorm WarningRAHCumberland, Harnett, Hoke, Lee, Moore64 min
Jul 28, 9:17 PM EDTSevere Thunderstorm WarningRAHChatham, Durham, Wake58 min
Jul 28, 9:23 PM EDTSevere Thunderstorm WarningRAHEdgecombe, Franklin, Halifax, Nash, Vance, Wake and 1 more52 min
Jul 28, 9:47 PM EDTSevere Thunderstorm WarningRAHJohnston58 min
Jul 28, 10:29 PM EDTSpecial Weather StatementRAHEdgecombe, Wayne, Wilson61 min

Nearby

Flash Flood Warnings in North Carolina, 2012Every 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.