Alert archive / North Carolina / Flash Flood Warnings in 2012

Flash Flood Warning 44, NWS Raleigh, NC

September 6, 2012Orange County, North Carolina

NWS Raleigh, NC issued this flash flood warning at Sep 6, 2012, 4:22 PM EDT for Orange County, North Carolina. It was in force for 2 hr. 4 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
Sep 6, 2012, 4:22 PM EDT (20:22 UTC)
Expired
Sep 6, 2012, 6:28 PM EDT
In force
2 hr
Issued by
NWS Raleigh, NC
Area
Storm-based polygon
Flood severity
None

County Orange County, NC

The radar

The Raleigh/Durham radar (KRAX), 62 km from the middle of the area, began a volume at 20:25 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
Sep 6, 4:53 PM EDTFLASH FLOOD1 Nw Chapel Hill, NCROAD CLOSURE AT PINEY MOUNTAIN RD AND MLK JR BLVD DUE TO FLOODING
Sep 6, 4:55 PM EDTFLASH FLOOD1 Nw Carrboro, NCROAD CLOSURES AT CAROL ST... AND THE HOLLOW AND HILLSBOROUGH DUE TO FLOODING
Sep 6, 4:55 PM EDTHEAVY RAIN 2.41Chapel Hill Apt, NCFELL WITHIN PAST HOUR AND HALF AND STILL RAINING
Sep 6, 5:53 PM EDTFLASH FLOOD1 Wsw Chapel Hill, NCROAD CLOSURE AT UMSTEAD AND BRADLEY ROAD 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 12:00Z, 8.4 hours before the alert went out and 75 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 12:00Z on 2012-09-06Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 843 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Greensboro/Hi Pt, NC at 12:00Z on 2012-09-06The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 78 square meters per square second.1939Sfc1 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
843 J/kg
Mixed-layer CIN
-23 J/kg
Mixed-layer LCL
721 m above ground
0-6 km bulk shear
22 kt
0-1 km storm-relative helicity
78 m²/s²
0-3 km storm-relative helicity
27 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.9

Open this sounding in Storm Lab

The text

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

602 
WGUS52 KRAH 062022
FFWRAH
NCC135-062315-
/O.NEW.KRAH.FF.W.0044.120906T2022Z-120906T2315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE RALEIGH NC
422 PM EDT THU SEP 6 2012

THE NATIONAL WEATHER SERVICE IN RALEIGH HAS ISSUED A

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

* UNTIL 715 PM EDT

* AT 416 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  THUNDERSTORMS WITH VERY HEAVY RAIN PRODUCING FLOODING OVER SOUTHERN
  ORANGE COUNTY. DOPPLER RADAR ESTIMATED THAT 2 TO 3 INCHES OF RAIN  
  HAS FALLEN OVER CHAPEL HILL AND DUKE FOREST.

* LOCATIONS THREATENED WITH FLOODING INCLUDE CHAPEL HILL AND
  CARRBORO.

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.

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.

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 3601 7899 3587 7901 3586 7902 3588 7925
      3602 7926

$$

SEC
2 follow-up statements
220 
WGUS72 KRAH 062108
FFSRAH

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE RALEIGH NC
508 PM EDT THU SEP 6 2012

NCC135-062315-
/O.CON.KRAH.FF.W.0044.000000T0000Z-120906T2315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
ORANGE NC-
508 PM EDT THU SEP 6 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 715 PM EDT FOR
SOUTHERN ORANGE COUNTY...

AT 502 PM EDT... NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO 
INDICATE THUNDERSTORMS WITH HEAVY RAINFALL OVER SOUTHERN ORANGE 
COUNTY. 2.5 INCHES OF RAIN HAS FALLEN AT THE CHAPEL HILL AIRPORT. 
MINOR STREET FLOODING HAS BEEN REPORTED AT CARRBORO.

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.

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 3601 7899 3587 7901 3586 7902 3588 7925
      3602 7926

$$

SEC
752 
WGUS72 KRAH 062228
FFSRAH

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE RALEIGH NC
628 PM EDT THU SEP 6 2012

NCC135-062236-
/O.CAN.KRAH.FF.W.0044.000000T0000Z-120906T2315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
ORANGE NC-
628 PM EDT THU SEP 6 2012

...THE FLASH FLOOD WARNING HAS BEEN CANCELLED FOR SOUTHERN ORANGE
COUNTY...

THUNDERSTORMS HAVE MOVED OUT OF THE AREA AND THE FLOODING THREAT HAS 
ENDED.

LAT...LON 3601 7899 3587 7901 3586 7902 3588 7925
      3602 7926

$$

SEC

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 6, 1:18 PM EDTSpecial Weather StatementRAHGranville, Halifax, Person, Vance, Warren57 min
Sep 6, 1:37 PM EDTSpecial Weather StatementRAHGranville, Halifax, Person, Vance, Warren53 min
Sep 6, 2:24 PM EDTSpecial Weather StatementRAHGranville, Halifax, Vance, Warren96 min
Sep 6, 2:39 PM EDTAreal Flood AdvisoryRAHHalifax3 hr
Sep 6, 3:42 PM EDTSpecial Weather StatementRAHWake63 min
Sep 6, 4:05 PM EDTAreal Flood AdvisoryRAHDurham, Orange3 hr
Sep 6, 4:22 PM EDTAreal Flood AdvisoryRAHWake3 hr
Sep 6, 4:29 PM EDTFlash Flood WarningRAHFranklin, Wake3 hr
Sep 6, 4:30 PM EDTSevere Thunderstorm WarningRAHJohnston, Wake60 min
Sep 6, 4:43 PM EDTSpecial Weather StatementRAHChatham17 min
Sep 6, 4:50 PM EDTSpecial Weather StatementRAHLee10 min
Sep 6, 5:34 PM EDTSpecial Weather StatementRAHJohnston56 min
Sep 6, 5:40 PM EDTSevere Thunderstorm WarningRAHJohnston, Sampson, Wayne52 min
Sep 6, 6:37 PM EDTSpecial Weather StatementRAHCumberland53 min
Sep 6, 7:23 PM EDTAreal Flood AdvisoryRAHCumberland3 hr
Sep 6, 7:43 PM EDTFlash Flood WarningRAHCumberland76 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.