Alert archive / North Carolina / Flash Flood Warnings in 2011

Flash Flood Warning 28, NWS Raleigh, NC

August 6, 2011Wake County, North Carolina

NWS Raleigh, NC issued this flash flood warning at Aug 6, 2011, 6:24 AM EDT for Wake County, North Carolina. It was in force for 3 hr. 10 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: Aug 6, 2011, 6:24 AM EDT (10:24 UTC)
Expired: Aug 6, 2011, 9:15 AM EDT
In force: 3 hr
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 10:28 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
Aug 6, 6:55 AM EDT	FLASH FLOOD	1 Sse Cary, NC	FLOODING CLOSED PAMLICO DRIVE IN CARY AT AROUND 655 AM.
Aug 6, 7:15 AM EDT	HEAVY RAIN 1.5	Holly Springs, NC	1.5 INCHES OF RAIN FELL IN LAST 30 MINS IN HOLLY SPRINGS.
Aug 6, 7:30 AM EDT	FLASH FLOOD	1 E Raleigh, NC	MILNER HOTEL ON 1817 CAPITAL BLVD. BEING EVACUATED DUE TO FLOODING
Aug 6, 7:30 AM EDT	FLASH FLOOD	1 Ese Raleigh, NC	CAPITAL INN FLOODED AT 1625 CAPITAL BLVD. BOTTOM UNITS BEING EVACUATED WITH THE ASSISTANCE OF THE RED CROSS.
Aug 6, 7:30 AM EDT	FLASH FLOOD	2 Sse Raleigh, NC	HOUSE FLOODED AT 320 HILL ST.
Aug 6, 7:30 AM EDT	HEAVY RAIN 4.25	2 N New Hope, NC	COCORAHS OBSERVER NEAR MINI CITY IN NORTH RALEIGH REPORTED 4.25 INCHES OF RAIN IN PAST 3 HOURS WITH 1.5 INCHES OF RAIN BETWEEN 700 AND 730 AM.
Aug 6, 7:50 AM EDT	FLASH FLOOD	3 Nnw New Hope, NC	NUMEROUS REPORTS OF ROADS FLOODED IN NORTH RALEIGH WITH PORTIONS OF SEVERAL ROADS CLOSED. FLOODING REPORTED ON CRAVEN ROAD... PORTIONS OF ATLANTIC AVENUE... BRENTWOOD ROAD... AND INTESTE 440 NEAR CAPITAL BLVD.
Aug 6, 8:30 AM EDT	HEAVY RAIN 5.31	2 Ene Raleigh, NC	5.31 INCHES OF RAIN IN A FOUR HOUR PERIOD IN NORTHEAST RALEIGH
Aug 6, 8:45 AM EDT	FLASH FLOOD	1 E Raleigh, NC	MILNER HOTEL ON 1817 CAPITAL BLVD. - 45 TO 50 PEOPLE DISPLACED TO SHELTER.
Aug 6, 9:00 AM EDT	HEAVY RAIN 4.64	2 Wnw New Hope, NC	MARSH CREEK RAIN GUAGE ON STONYBROOK RD NEAR BRENTWOOD RD REPORTED 4.64 INCHES OF RAIN IN 6 HOURS.

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, 10.4 hours before the alert went out and 119 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: 299 J/kg
Mixed-layer CIN: -103 J/kg
Mixed-layer LCL: 1023 m above ground
0-6 km bulk shear: 18 kt
0-1 km storm-relative helicity: 60 m²/s²
0-3 km storm-relative helicity: 107 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.

156 
WGUS52 KRAH 061024
FFWRAH
NCC183-061315-
/O.NEW.KRAH.FF.W.0028.110806T1024Z-110806T1315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE RALEIGH NC
624 AM EDT SAT AUG 6 2011

THE NATIONAL WEATHER SERVICE IN RALEIGH HAS ISSUED A

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

* UNTIL 915 AM EDT

* AT 617 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  THUNDERSTORMS THAT WERE CONTINUOUSLY REDEVELOPING AND PRODUCING   
FLOODING OVER WAKE COUNTY. DOPPLER RADAR ESTIMATED THAT TWO TO THREE 
INCHES OF RAIN HAS FALLEN OVER WESTERN WAKE COUNTY...IN CARY AND 
MORRISVILLE. ANOTHER SWATH OF ONE TO TWO INCHES OF RAIN HAS FALLEN 
OVER EAST RALEIGH. 

* LOCATIONS THREATENED WITH FLOODING INCLUDE WAKE FOREST...RDU   
INTERNATIONAL AIRPORT...RALEIGH...GARNER...CARY AND MORRISVILLE.

AN ADDITIONAL ONE TO TWO INCHES OF RAINFALL ARE STILL POSSIBLE 
RESULTING IN ADDITIONAL FLOODING.

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.

&&

LAT...LON 3599 7845 3594 7839 3593 7835 3591 7835
      3587 7828 3583 7826 3578 7832 3571 7847
      3552 7871 3562 7899 3586 7890 3587 7883
      3593 7881 3592 7876 3597 7871 3601 7870
      3603 7875 3608 7874 3607 7868

$$

23

1 follow-up statement

088 
WGUS72 KRAH 061141
FFSRAH

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE RALEIGH NC
741 AM EDT SAT AUG 6 2011

NCC183-061315-
/O.CON.KRAH.FF.W.0028.000000T0000Z-110806T1315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
WAKE NC-
741 AM EDT SAT AUG 6 2011

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 915 AM EDT FOR WAKE 
COUNTY...WITH FLOODING DEVELOPING ALONG CRABTREE CREEK...

AT 730 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE THUNDERSTORMS WITH VERY HEAVY RAIN OVER WAKE COUNTY. DOPPLER
RADAR ESTIMATED THAT 3 TO 5 INCHES OF RAIN HAS FALLEN OVER CENTRAL 
WAKE COUNTY...NEAR RALEIGH...CARY AND MORRISVILLE.

CRABTREE CREEK NEAR WAKE FOREST ROAD HAS RISEN ABOVE FLOOD STAGE 
WHICH WILL RESULT IN FLOODING OF SOME OF THE COMMERCIAL PARKING 
LOTS AND THE SECONDARY ROADS NEAR ATLANTIC AVENUE. CRABTREE CREEK IS 
ALSO RISING RAPIDLY NEAR GLENWOOD AVENUE...WHICH MAY RESULT IN WATER 
BEGINNING TO ENTER THE LOWER PARKING LOT AT CRABTREE VALLEY MALL.  


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 3599 7845 3594 7839 3593 7835 3591 7835
      3587 7828 3583 7826 3578 7832 3571 7847
      3552 7871 3562 7899 3586 7890 3587 7883
      3593 7881 3592 7876 3597 7871 3601 7870
      3603 7875 3608 7874 3607 7868

$$

KRR

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 6, 5:01 AM EDT	Special Weather Statement	RAH	Wake	89 min
Aug 6, 5:14 AM EDT	Areal Flood Advisory	RAH	Wake	3 hr
Aug 6, 7:31 AM EDT	Areal Flood Advisory	RAH	Chatham, Durham, Granville, Orange	119 min
Aug 6, 8:02 AM EDT	Areal Flood Advisory	RAH	Franklin, Nash	3 hr
Aug 6, 8:09 AM EDT	Flash Flood Warning	RAH	Franklin, Nash	4 hr
Aug 6, 8:49 AM EDT	Flash Flood Warning	RAH	Wake	3 hr
Aug 6, 11:16 AM EDT	Tornado Warning	RAH	Wilson	44 min
Aug 6, 4:36 PM EDT	Severe Thunderstorm Warning	RAH	Davidson	32 min
Aug 6, 6:48 PM EDT	Areal Flood Advisory	RAH	Sampson	102 min
Aug 6, 6:55 PM EDT	Special Weather Statement	RAH	Montgomery, Randolph, Stanly	110 min
Aug 6, 6:56 PM EDT	Special Weather Statement	RAH	Montgomery, Randolph, Stanly	109 min
Aug 6, 7:24 PM EDT	Special Weather Statement	RAH	Person	51 min
Aug 6, 7:30 PM EDT	Severe Thunderstorm Warning	RAH	Montgomery, Stanly	46 min

Nearby

Flash Flood Warnings in North Carolina, 2011 Every flash flood warning in 2011

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.