Alert archive / North Carolina / Flash Flood Warnings in 2012

Flash Flood Warning 17, NWS Raleigh, NC

July 9, 2012Guilford County, North Carolina

NWS Raleigh, NC issued this flash flood warning at Jul 9, 2012, 10:42 PM EDT for Guilford County, North Carolina. It was in force for 2 hr. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Jul 9, 2012, 10:42 PM EDT (02:42 UTC)
Expired
Jul 10, 2012, 12:49 AM EDT
In force
2 hr
Issued by
NWS Raleigh, NC
Area
Storm-based polygon
Flood severity
None

County Guilford County, NC

The radar

The Roanoke radar (KFCX), 114 km from the middle of the area, began a volume at 02:43 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, 2.7 hours before the alert went out and 131 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, Roanoke, VA at 00:00Z on 2012-07-10Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 440 joules per kilogram.LCLLFCEL10008507005003002001001 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, Roanoke, VA at 00:00Z on 2012-07-10The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -35 square meters per square second.193958Sfc1 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
440 J/kg
Mixed-layer CIN
-30 J/kg
Mixed-layer LCL
900 m above ground
0-6 km bulk shear
33 kt
0-1 km storm-relative helicity
-35 m²/s²
0-3 km storm-relative helicity
28 m²/s²
Significant tornado parameter
-0.1
Supercell composite
-1.1

Open this sounding in Storm Lab

The text

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

371 
WGUS52 KRAH 100242
FFWRAH
NCC081-100545-
/O.NEW.KRAH.FF.W.0017.120710T0242Z-120710T0545Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE RALEIGH NC
1042 PM EDT MON JUL 9 2012

THE NATIONAL WEATHER SERVICE IN RALEIGH HAS ISSUED A

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

* UNTIL 145 AM EDT

* AT 1037 PM EDT...LOCAL LAW ENFORCEMENT REPORTED THUNDERSTORMS THAT
  WERE CONTINUOUSLY REDEVELOPING AND PRODUCING FLOODING OVER CENTRAL 
  GUILFORD COUNTY. FLASH FLOODING CURRENTLY ONGOING HAS CLOSED I-40  
  WESTBOUND AT HIGHWAY 68 IN GREENSBORO. LIGHT TO MODERATE SHOWERS 
  WILL CONTINUE FOR THE NEXT HOUR OR SO.

* LOCATIONS THREATENED WITH FLOODING INCLUDE GREENSBORO.

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 3599 7972 3599 8001 3616 8002 3615 7973

$$

ELLIS
2 follow-up statements
059 
WGUS72 KRAH 100402
FFSRAH

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE RALEIGH NC
1202 AM EDT TUE JUL 10 2012

NCC081-100545-
/O.CON.KRAH.FF.W.0017.000000T0000Z-120710T0545Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
GUILFORD NC-
1202 AM EDT TUE JUL 10 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 145 AM EDT FOR
CENTRAL GUILFORD COUNTY...

AT 1155 PM EDT...THE HEAVY RAINFALL WAS DIMINISHING ACROSS 
GREENSBORO. WHILE AREA CREEKS AND STREAMS WERE BEGINNING TO 
RECEDE...WATER LEVELS WERE STILL HIGH AND WATER WAS FLOWING SWIFTLY. 
ONCE MOST CREEKS AND STREAMS RETURN TO THEIR BANKS...THE FLASH FLOOD 
WARNING WILL BE CANCELED. 

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.

&&

LAT...LON 3599 7972 3599 8001 3616 8002 3615 7973

$$

WSS
658 
WGUS72 KRAH 100449
FFSRAH

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE RALEIGH NC
1249 AM EDT TUE JUL 10 2012

NCC081-100505-
/O.CAN.KRAH.FF.W.0017.000000T0000Z-120710T0545Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
GUILFORD NC-
1249 AM EDT TUE JUL 10 2012

...THE FLASH FLOOD WARNING HAS BEEN CANCELLED FOR CENTRAL GUILFORD
COUNTY...

AT 1241 AM EDT...THE VERY HEAVY RAINFALL THAT OCCURRED MONDAY 
EVENING HAS DISSIPATED AND CREEKS AND STREAMS HAVE RETURNED TO THEIR 
BANKS. SINCE THE THREAT OF FLASH FLOODING HAS ENDED...THE FLASH 
FLOOD WARNING HAS BEEN CANCELED. GUILFORD COUNTY OFFICIALS REPORT 
I-40 WESTBOUND HAS REOPENED AS WELL AS OTHER STREETS THAT WERE 
CLOSED EARLIER DUE TO HIGH WATER.


LAT...LON 3599 7972 3599 8001 3616 8002 3615 7973

$$

WSS

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 9, 8:08 PM EDTSpecial Weather StatementRAHAlamance, Davidson, Durham, Guilford, Orange, Vance and 1 more52 min
Jul 9, 8:15 PM EDTAreal Flood AdvisoryRAHFranklin, Halifax, Nash, Warren2 hr
Jul 9, 8:46 PM EDTSpecial Weather StatementRAHEdgecombe, Franklin, Halifax, Nash, Wilson59 min
Jul 9, 8:57 PM EDTSpecial Weather StatementRAHAlamance, Chatham, Davidson, Durham, Guilford, Lee and 3 more93 min
Jul 9, 9:28 PM EDTAreal Flood AdvisoryRAHChatham, Randolph75 min
Jul 9, 10:49 PM EDTSpecial Weather StatementRAHHarnett56 min
Jul 10, 12:58 PM EDTSpecial Weather StatementRAHAlamance, Durham, Franklin, Orange47 min
Jul 10, 2:24 PM EDTSpecial Weather StatementRAHDavidson66 min
Jul 10, 2:44 PM EDTAreal Flood AdvisoryRAHEdgecombe, Nash, Wilson2 hr
Jul 10, 3:29 PM EDTSpecial Weather StatementRAHDavidson61 min
Jul 10, 4:11 PM EDTSpecial Weather StatementRAHMontgomery, Randolph64 min
Jul 10, 4:17 PM EDTAreal Flood AdvisoryRAHDavidson2 hr
Jul 10, 5:09 PM EDTSpecial Weather StatementRAHMontgomery, Moore66 min
Jul 10, 5:14 PM EDTSevere Thunderstorm WarningRAHMontgomery, Moore, Richmond46 min
Jul 10, 5:22 PM EDTSpecial Weather StatementRAHAnson53 min
Jul 10, 5:50 PM EDTAreal Flood AdvisoryRAHAnson, Montgomery, Moore, Richmond, Stanly100 min
Jul 10, 6:10 PM EDTSpecial Weather StatementRAHCumberland65 min
Jul 10, 6:17 PM EDTSpecial Weather StatementRAHHoke, Moore58 min
Jul 10, 6:26 PM EDTSpecial Weather StatementRAHScotland64 min
Jul 10, 6:35 PM EDTAreal Flood AdvisoryRAHCumberland, Hoke, Sampson, Scotland3 hr
Jul 10, 6:45 PM EDTSevere Thunderstorm WarningRAHHoke, Scotland45 min
Jul 10, 7:10 PM EDTSpecial Weather StatementRAHAnson50 min
Jul 10, 7:13 PM EDTFlash Flood WarningRAHCumberland3 hr
Jul 10, 7:31 PM EDTSpecial Weather StatementRAHCumberland59 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.