Alert archive / North Carolina / Flash Flood Warnings in 2012

Flash Flood Warning 40, NWS Raleigh, NC

September 3, 2012Forsyth County, North Carolina

NWS Raleigh, NC issued this flash flood warning at Sep 3, 2012, 1:01 PM EDT for Forsyth County, North Carolina. It was in force for 3 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
Sep 3, 2012, 1:01 PM EDT (17:01 UTC)
Expired
Sep 3, 2012, 4:00 PM EDT
In force
3 hr
Issued by
NWS Raleigh, NC
Area
Storm-based polygon
Flood severity
None

County Forsyth County, NC

The radar

The Roanoke radar (KFCX), 105 km from the middle of the area, began a volume at 17:04 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

Greensboro/Hi Pt, NC (KGSO), launched 12:00Z, 5.0 hours before the alert went out and 42 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 2012-09-03Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 576 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, Greensboro/Hi Pt, NC at 12:00Z on 2012-09-03The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 57 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
576 J/kg
Mixed-layer CIN
-44 J/kg
Mixed-layer LCL
801 m above ground
0-6 km bulk shear
17 kt
0-1 km storm-relative helicity
57 m²/s²
0-3 km storm-relative helicity
44 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

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

673 
WGUS52 KRAH 031701
FFWRAH
NCC067-032000-
/O.NEW.KRAH.FF.W.0040.120903T1701Z-120903T2000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE RALEIGH NC
101 PM EDT MON SEP 3 2012

THE NATIONAL WEATHER SERVICE IN RALEIGH HAS ISSUED A

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

* UNTIL 400 PM EDT

* AT 1256 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  THUNDERSTORMS WITH VERY HEAVY RAIN PRODUCING FLOODING OVER         
  FORSYTH COUNTY. DOPPLER RADAR ESTIMATED THAT ONE TO TWO INCHES OF  
  RAIN HAS FALLEN OVER WINSTON SALEM.

* LOCATIONS THREATENED WITH FLOODING INCLUDE WINSTON-SALEM...        
  KERNERSVILLE...CLEMMONS.

AN ADDITIONAL ONE TO TWO 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.

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 3614 8044 3622 8044 3626 8045 3626 8003
      3601 8005 3603 8021 3600 8022 3600 8032
      3597 8040 3599 8043 3601 8042 3606 8047
      3604 8048 3605 8051 3611 8051

$$

10
2 follow-up statements
567 
WGUS72 KRAH 031813
FFSRAH

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE RALEIGH NC
213 PM EDT MON SEP 3 2012

NCC067-032000-
/O.CON.KRAH.FF.W.0040.000000T0000Z-120903T2000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
FORSYTH NC-
213 PM EDT MON SEP 3 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 400 PM EDT FOR
FORSYTH COUNTY...

AT 208 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR ESTIMATED 
THAT OVER 3 INCHES OF RAIN HAS FALLEN OVER WINSTON SALEM. ALTHOUGH 
THE STORMS HAVE MOVED OUT OF THE AREA...ANOTHER ROUND OF STORMS WITH 
HEAVY RAIN IS LIKELY OVER FORSYTH COUNTY THROUGH 4 PM.

LOCATIONS THREATENED BY FLOODING INCLUDE BUT ARE NOT LIMITED TO 
WINSTON-SALEM AND KERNERSVILLE.

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 3614 8044 3622 8044 3626 8045 3626 8003
      3601 8005 3603 8021 3600 8022 3600 8032
      3597 8040 3599 8043 3601 8042 3606 8047
      3604 8048 3605 8051 3611 8051

$$

10
415 
WGUS72 KRAH 031954
FFSRAH

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE RALEIGH NC
354 PM EDT MON SEP 3 2012

NCC067-032003-
/O.EXP.KRAH.FF.W.0040.000000T0000Z-120903T2000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
FORSYTH NC-
354 PM EDT MON SEP 3 2012

...THE FLASH FLOOD WARNING WILL EXPIRE AT 400 PM EDT FOR FORSYTH
COUNTY...

AT 351 PM EDT...THE THUNDERSTORMS THAT WERE PRODUCING VERY HEAVY 
RAIN OVER FORSYTH COUNTY HAVE WEAKENED AND MOVED OUT OF THE AREA. 
THE FLOODING THREAT HAS ENDED AND THE WARNING WILL BE ALLOWED TO 
EXPIRE.


LAT...LON 3614 8044 3622 8044 3626 8045 3626 8003
      3601 8005 3603 8021 3600 8022 3600 8032
      3597 8040 3599 8043 3601 8042 3606 8047
      3604 8048 3605 8051 3611 8051

$$

10

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 2, 8:20 PM EDTSpecial Weather StatementRAHAlamance, Orange85 min
Sep 2, 8:28 PM EDTSevere Thunderstorm WarningRAHAlamance, Durham, Orange, Person53 min
Sep 2, 8:42 PM EDTTornado WarningRAHDurham, Orange, Person33 min
Sep 2, 9:20 PM EDTSpecial Weather StatementRAHGranville, Vance55 min
Sep 2, 9:43 PM EDTSpecial Weather StatementRAHChatham, Durham, Lee, Moore, Orange62 min
Sep 2, 10:26 PM EDTSpecial Weather StatementRAHLee, Wake94 min
Sep 2, 11:09 PM EDTSpecial Weather StatementRAHFranklin, Granville, Nash, Wake51 min
Sep 2, 11:42 PM EDTAreal Flood AdvisoryRAHWake108 min
Sep 3, 2:35 AM EDTAreal Flood AdvisoryRAHMontgomery, Richmond99 min
Sep 3, 1:00 PM EDTSpecial Weather StatementRAHDavidson, Forsyth, Guilford, Randolph90 min
Sep 3, 1:06 PM EDTSpecial Weather StatementRAHAnson, Montgomery, Stanly84 min
Sep 3, 1:09 PM EDTAreal Flood AdvisoryRAHStanly3 hr
Sep 3, 1:18 PM EDTFlash Flood WarningRAHStanly3 hr
Sep 3, 1:21 PM EDTSevere Thunderstorm WarningRAHForsyth, Guilford39 min
Sep 3, 1:27 PM EDTSevere Thunderstorm WarningRAHMontgomery, Randolph, Stanly48 min
Sep 3, 2:23 PM EDTAreal Flood AdvisoryRAHGuilford3 hr
Sep 3, 2:35 PM EDTSpecial Weather StatementRAHAnson, Montgomery, Moore, Richmond, Stanly85 min
Sep 3, 2:38 PM EDTSpecial Weather StatementRAHDavidson, Forsyth, Guilford, Randolph97 min
Sep 3, 2:53 PM EDTFlash Flood WarningRAHGuilford3 hr
Sep 3, 3:34 PM EDTAreal Flood AdvisoryRAHRandolph2 hr
Sep 3, 3:59 PM EDTSpecial Weather StatementRAHHoke, Lee, Moore, Richmond, Scotland91 min
Sep 3, 4:03 PM EDTSpecial Weather StatementRAHAlamance, Chatham, Orange87 min
Sep 3, 4:14 PM EDTFlash Flood WarningRAHStanly2 hr
Sep 3, 4:17 PM EDTSevere Thunderstorm WarningRAHAlamance, Orange58 min
Sep 3, 4:52 PM EDTAreal Flood AdvisoryRAHAlamance, Orange2 hr
Sep 3, 4:57 PM EDTSevere Thunderstorm WarningRAHRichmond, Scotland48 min
Sep 3, 5:40 PM EDTAreal Flood AdvisoryRAHDurham, Orange3 hr
Sep 3, 5:41 PM EDTSpecial Weather StatementRAHWake64 min
Sep 3, 5:49 PM EDTSpecial Weather StatementRAHWilson56 min
Sep 3, 6:21 PM EDTSpecial Weather StatementRAHDurham54 min
Sep 3, 7:41 PM EDTSpecial Weather StatementRAHWake64 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.