Alert archive / North Carolina / Flash Flood Warnings in 2003

Flash Flood Warning 70, NWS Raleigh, NC

August 9, 2003Alamance County, North Carolina

NWS Raleigh, NC issued this flash flood warning at Aug 9, 2003, 7:58 PM EDT for Alamance 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 counties it named.

The facts

Issued
Aug 9, 2003, 7:58 PM EDT (23:58 UTC)
Expired
Aug 9, 2003, 10:00 PM EDT
In force
2 hr
Issued by
NWS Raleigh, NC
Area
Whole counties

County Alamance County, NC

The radar

The Raleigh/Durham radar (KRAX), 92 km from the middle of the area, began a volume at 00:02 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, 12.0 hours before the alert went out and 45 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 2003-08-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1271 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 2003-08-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 25 square meters per square second.1939587897Sfc1 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
1271 J/kg
Mixed-layer CIN
-6 J/kg
Mixed-layer LCL
542 m above ground
0-6 km bulk shear
33 kt
0-1 km storm-relative helicity
25 m²/s²
0-3 km storm-relative helicity
53 m²/s²
Significant tornado parameter
0.2
Supercell composite
0.9

Open this sounding in Storm Lab

The text

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

000 
WGUS52 KRAH 100000
FFWRAH
NCC001-100100-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE RALEIGH NC
758 PM EDT SAT AUG 9 2003

THE NATIONAL WEATHER SERVICE IN RALEIGH HAS ISSUED A

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

* UNTIL 1000 PM EDT

* AT 758 PM EDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED     
  THUNDERSTORMS WITH VERY HEAVY RAIN REDEVELOPING OVER ELON
  COLLEGE TO BURLINGTON.

* SLOW MOVING THUNDERSTORMS WILL PRODUCE FLOODING AROUND...
  GRAHAM.
  ELON COLLEGE.
  BURLINGTON.

THUNDERSTORMS HAD ALREADY PRODUCED RAINFALL IN EXCESS OF
2 INCHES IN THESE AREAS. ANY ADDITIONAL RAINFALL WILL
PRODUCE RAPID RUNOFF CREATING FLASH FLOODING. 

A FLASH FLOOD WARNING MEANS THAT FLOODING IS IMMINENT OR OCCURRING.
IF YOU ARE EXPERIENCING FLOODING OR LIVE IN A FLOOD PRONE AREA MOVE
TO HIGHER GROUND IMMEDIATELY.

$$

PWB

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 8, 8:08 PM EDTFlash Flood WarningRAHFranklin2 hr
Aug 8, 8:26 PM EDTFlash Flood WarningRAHLee2 hr
Aug 8, 8:27 PM EDTFlash Flood WarningRAHWake2 hr
Aug 8, 10:17 PM EDTFlash Flood WarningRAHFranklin88 min
Aug 9, 6:15 PM EDTFlash Flood WarningRAHMoore90 min
Aug 9, 7:45 PM EDTFlash Flood WarningRAHMoore75 min

Nearby

Flash Flood Warnings in North Carolina, 2003Every flash flood warning in 2003

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.