Alert archive / North Carolina / Flash Flood Warnings in 2012

Flash Flood Warning 48, NWS Raleigh, NC

September 18, 2012Wake County, North Carolina

NWS Raleigh, NC issued this flash flood warning at Sep 18, 2012, 3:37 PM EDT for Wake County, North Carolina. It was in force for 93 min. 2 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 18, 2012, 3:37 PM EDT (19:37 UTC)
Expired: Sep 18, 2012, 5:10 PM EDT
In force: 93 min
Issued by: NWS Raleigh, NC
Area: Storm-based polygon
Flood severity: None

County Wake County, NC

The radar

The Raleigh/Durham radar (KRAX), 27 km from the middle of the area, began a volume at 19:41 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
Sep 18, 4:00 PM EDT	FLASH FLOOD	2 Ene Raleigh, NC	SEVERAL REPORTS OF HIGH WATER AROUND RALEIGH... INCLUDING WATER ONE FOOT DEEP AT SIX FORKS AND WAKE FOREST ROAD... AND ROADWAY FLOODED AT ATLANTIC AVE AND 440. ROAD BEING BLOCKED BY POLICE AT TIME OF CALL.
Sep 18, 5:00 PM EDT	FLASH FLOOD	2 Ene Raleigh, NC	FLASH FLOODING ABATED. NO KNOWN ROAD CLOSURES.

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, 7.6 hours before the alert went out and 115 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: 533 J/kg
Mixed-layer CIN: 0 J/kg
Mixed-layer LCL: 545 m above ground
0-6 km bulk shear: 35 kt
0-1 km storm-relative helicity: 221 m²/s²
0-3 km storm-relative helicity: 313 m²/s²
Significant tornado parameter: 0.5
Supercell composite: 4.1

Open this sounding in Storm Lab

The text

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

983 
WGUS52 KRAH 181937
FFWRAH
NCC183-182200-
/O.NEW.KRAH.FF.W.0048.120918T1937Z-120918T2200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE RALEIGH NC
337 PM EDT TUE SEP 18 2012

THE NATIONAL WEATHER SERVICE IN RALEIGH HAS ISSUED A

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

* UNTIL 600 PM EDT

* AT 331 PM EDT...SKYWARN SPOTTERS REPORTED THUNDERSTORMS WITH VERY  
  HEAVY RAIN PRODUCING HIGH WATER ON ROADS IN WAKE FOREST AND IN     
  RALEIGH. DOPPLER RADAR ESTIMATED THAT 1 TO 1.5 INCHES OF RAIN      
  HAS FALLEN OVER WAKE COUNTY BETWEEN 3 AND 330 PM. MORE RAIN MOVING 
  IN FROM THE WEST COULD BRING UP TO ANOTHER INCH OF RAIN TO THE     
  AREA.

* LOCATIONS THREATENED WITH FLOODING INCLUDE WAKE FOREST...RDU
  INTERNATIONAL...RALEIGH...GARNER...FUQUAY-VARINA AND CARY.

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 3598 7844 3588 7830 3583 7826 3580 7828
      3571 7847 3552 7871 3561 7899 3585 7891
      3587 7889 3587 7883 3593 7881 3592 7876
      3598 7871 3603 7871 3604 7876 3608 7872

$$

SEC

4 follow-up statements

060 
WGUS72 KRAH 181957
FFSRAH

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE RALEIGH NC
357 PM EDT TUE SEP 18 2012

NCC183-182200-
/O.CON.KRAH.FF.W.0048.000000T0000Z-120918T2200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
WAKE NC-
357 PM EDT TUE SEP 18 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 600 PM EDT FOR WAKE
COUNTY...

AT 350 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED  
THUNDERSTORMS WITH VERY HEAVY RAIN MOVING INTO WESTERN WAKE COUNTY. 
THUNDERSTORMS WILL CROSS THE COUNTY OVER THE NEXT HOUR. STANDING 
WATER HAS BEEN REPORTED ON ROADS IN RALEIGH AND WAKE FOREST. ANOTHER 
ONE HALF TO ONE INCH OF RAIN IS POSSIBLE AS THE NEXT ROUND OF STORMS 
MOVES THROUGH.

LOCATIONS THREATENED BY FLOODING INCLUDE BUT ARE NOT LIMITED TO RDU
INTERNATIONAL AND WAKE FOREST

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.

A TORNADO WATCH REMAINS IN EFFECT UNTIL 500 PM EDT TUESDAY AFTERNOON
FOR CENTRAL NORTH CAROLINA.

&&

LAT...LON 3598 7844 3588 7830 3583 7826 3580 7828
      3571 7847 3552 7871 3561 7899 3585 7891
      3587 7889 3587 7883 3593 7881 3592 7876
      3598 7871 3603 7871 3604 7876 3608 7872

$$

SEC

355 
WGUS72 KRAH 182021
FFSRAH

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE RALEIGH NC
421 PM EDT TUE SEP 18 2012

NCC183-182200-
/O.CON.KRAH.FF.W.0048.000000T0000Z-120918T2200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
WAKE NC-
421 PM EDT TUE SEP 18 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 600 PM EDT FOR WAKE
COUNTY...

AT 413 PM EDT...DOPPLER RADAR INDICATED THUNDERSTORMS WITH HEAVY 
RAIN OVER WAKE COUNTY. LOCAL LAW ENFORCEMENT REPORTED ATLANTIC 
AVENUE AND 4 40 IS FLOODED AND CLOSED OFF BY POLICE. WATER 
ONE FOOT DEEP WAS REPORTED AT SIX FORKS AND WAKE FOREST ROAD.

LOCATIONS THREATENED BY FLOODING INCLUDE BUT ARE NOT LIMITED TO RDU 
INTERNATIONAL... WAKE FOREST... AND RALEIGH.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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.

A TORNADO WATCH REMAINS IN EFFECT UNTIL 500 PM EDT TUESDAY AFTERNOON
FOR CENTRAL NORTH CAROLINA.

&&

LAT...LON 3598 7844 3588 7830 3583 7826 3580 7828
      3571 7847 3552 7871 3561 7899 3585 7891
      3587 7889 3587 7883 3593 7881 3592 7876
      3598 7871 3603 7871 3604 7876 3608 7872

$$

SEC

566 
WGUS72 KRAH 182059
FFSRAH

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE RALEIGH NC
459 PM EDT TUE SEP 18 2012

NCC183-182200-
/O.CON.KRAH.FF.W.0048.000000T0000Z-120918T2200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
WAKE NC-
459 PM EDT TUE SEP 18 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 600 PM EDT FOR
NORTHERN WAKE COUNTY...

AT 454 PM EDT...DOPPLER RADAR ESTIMATED THAT 1 TO 1.5 INCHES OF RAIN 
HAS FALLEN OVER THE AREA. WHILE MOST OF THE HEAVY RAIN HAS MOVED OUT 
OF THE AREA... WATER MAY CONTINUE TO RISE DUE TO RUNOFF IN URBAN 
AREAS.

LOCATIONS THREATENED BY FLOODING INCLUDE BUT ARE NOT LIMITED TO WAKE 
FOREST... RDU INTERNATIONAL... AND RALEIGH.

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.

A TORNADO WATCH REMAINS IN EFFECT UNTIL 600 PM EDT TUESDAY EVENING
FOR CENTRAL NORTH CAROLINA.

&&

LAT...LON 3598 7844 3588 7830 3583 7826 3580 7828
      3571 7848 3578 7893 3587 7889 3587 7883
      3593 7880 3592 7876 3595 7873 3601 7870
      3603 7871 3604 7876 3608 7872

$$

SEC

805 
WGUS72 KRAH 182110
FFSRAH

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE RALEIGH NC
510 PM EDT TUE SEP 18 2012

NCC183-182118-
/O.CAN.KRAH.FF.W.0048.000000T0000Z-120918T2200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
WAKE NC-
510 PM EDT TUE SEP 18 2012

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

AT 503 PM EDT...LOCAL LAW ENFORCEMENT REPORTED THAT NO ROADS WERE 
KNOWN TO BE CLOSED DUE TO EARLIER HEAVY RAINFALL. NATIONAL WEATHER 
SERVICE DOPPLER RADAR INDICATED ONLY VERY LIGHT RAIN IN AND AROUND 
THE CITY OF RALEIGH. AS A RESULT...THE FLASH FLOOD WARNING HAS BEEN 
CANCELLED.

STILL...STANDING WATER MAY STILL EXIST...ESPECIALLY ON OUTER LANES 
AND IN LOW SPOTS. DURING THE EVENING COMMUTE...USE EXTRA CAUTION. 
DRIVE CAREFULLY TO AVOID HYDROPLANING. STAY TUNED TO THIS STATION 
FOR THE LATEST WEATHER INFORMATION.

LAT...LON 3598 7844 3588 7830 3583 7826 3580 7828
      3571 7848 3578 7893 3587 7889 3587 7883
      3593 7880 3592 7876 3595 7873 3601 7870
      3603 7871 3604 7876 3608 7872

$$

DJF

The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 17, 8:32 PM EDT	Special Weather Statement	RAH	Davie	58 min
Sep 17, 10:33 PM EDT	Special Weather Statement	RAH	Forsyth	27 min
Sep 18, 6:52 AM EDT	Special Weather Statement	RAH	Anson, Stanly	38 min
Sep 18, 7:46 AM EDT	Special Weather Statement	RAH	Anson, Montgomery, Richmond, Stanly	89 min
Sep 18, 8:04 AM EDT	Special Weather Statement	RAH	Davidson, Guilford, Randolph	86 min
Sep 18, 8:34 AM EDT	Special Weather Statement	RAH	Montgomery	56 min
Sep 18, 8:56 AM EDT	Special Weather Statement	RAH	Alamance, Chatham, Guilford, Randolph	94 min
Sep 18, 9:34 AM EDT	Severe Thunderstorm Warning	RAH	Alamance, Chatham, Orange	56 min
Sep 18, 10:45 AM EDT	Severe Thunderstorm Warning	RAH	Durham, Granville, Person, Vance	45 min
Sep 18, 11:35 AM EDT	Special Weather Statement	RAH	Orange	40 min
Sep 18, 11:52 AM EDT	Areal Flood Advisory	RAH	Alamance, Chatham, Randolph	2 hr
Sep 18, 12:03 PM EDT	Special Weather Statement	RAH	Granville, Orange	57 min
Sep 18, 12:14 PM EDT	Special Weather Statement	RAH	Chatham	31 min
Sep 18, 12:50 PM EDT	Special Weather Statement	RAH	Person	25 min
Sep 18, 12:55 PM EDT	Special Weather Statement	RAH	Anson, Montgomery, Moore, Richmond, Scotland	65 min
Sep 18, 1:29 PM EDT	Special Weather Statement	RAH	Granville	46 min
Sep 18, 1:37 PM EDT	Severe Thunderstorm Warning	RAH	Granville, Vance	53 min
Sep 18, 1:40 PM EDT	Severe Thunderstorm Warning	RAH	Franklin, Halifax, Warren	35 min
Sep 18, 1:47 PM EDT	Special Weather Statement	RAH	Chatham, Harnett, Hoke, Lee	58 min
Sep 18, 2:27 PM EDT	Special Weather Statement	RAH	Alamance, Chatham, Orange, Randolph	63 min
Sep 18, 2:37 PM EDT	Tornado Warning	RAH	Granville	21 min
Sep 18, 2:40 PM EDT	Special Weather Statement	RAH	Cumberland, Harnett, Johnston	65 min
Sep 18, 2:43 PM EDT	Special Weather Statement	RAH	Franklin, Wake	62 min
Sep 18, 2:51 PM EDT	Severe Thunderstorm Warning	RAH	Harnett, Johnston, Wake	54 min
Sep 18, 3:04 PM EDT	Areal Flood Advisory	RAH	Wake	2 hr
Sep 18, 3:13 PM EDT	Special Weather Statement	RAH	Chatham, Durham, Granville, Vance	32 min
Sep 18, 3:19 PM EDT	Severe Thunderstorm Warning	RAH	Cumberland, Harnett, Johnston, Sampson	41 min
Sep 18, 3:24 PM EDT	Tornado Warning	RAH	Cumberland, Johnston, Sampson	23 min
Sep 18, 3:27 PM EDT	Special Weather Statement	RAH	Warren	33 min
Sep 18, 3:38 PM EDT	Tornado Warning	RAH	Franklin, Nash, Wake	14 min
Sep 18, 3:52 PM EDT	Special Weather Statement	RAH	Johnston, Wilson	53 min
Sep 18, 3:56 PM EDT	Special Weather Statement	RAH	Halifax, Nash	64 min
Sep 18, 5:01 PM EDT	Special Weather Statement	RAH	Halifax	44 min
Sep 18, 5:09 PM EDT	Areal Flood Advisory	RAH	Halifax	85 min

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.