Alert archive / North Carolina / Flash Flood Warnings in 2002

Flash Flood Warning 44, NWS Raleigh, NC

September 18, 2002Forsyth County, North Carolina

NWS Raleigh, NC issued this flash flood warning at Sep 18, 2002, 4:30 PM EDT for Forsyth 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
Sep 18, 2002, 4:30 PM EDT (20:30 UTC)
Expired
Sep 18, 2002, 6:30 PM EDT
In force
2 hr
Issued by
NWS Raleigh, NC
Area
Whole counties

County Forsyth County, NC

The radar

The Roanoke radar (KFCX), 99 km from the middle of the area, began a volume at 20:31 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, 8.5 hours before the alert went out and 32 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 2002-09-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1538 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 2002-09-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 49 square meters per square second.19395878Sfc1 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
1538 J/kg
Mixed-layer CIN
-5 J/kg
Mixed-layer LCL
537 m above ground
0-6 km bulk shear
19 kt
0-1 km storm-relative helicity
49 m²/s²
0-3 km storm-relative helicity
69 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.

000 
WGUS52 KRAH 182030
FFWRAH
NCC067-182230-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE RALEIGH NC
426 PM EDT WED SEP 18 2002

THE NATIONAL WEATHER SERVICE IN RALEIGH HAS ISSUED A

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

* UNTIL 630 PM EDT

* AT 426 PM EDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED VERY
  HEAVY RAIN OVER THE FORSYTH COUNTY...ESPECIALLY TO THE NORTH AND 
  WEST OF WINSTON-SALEM.

* THUNDERSTORMS ARE CONTINUOUSLY REDEVELOPING OVER THE WARNED AREA...
  RESULTING IN EXCESSIVE RAINFALL.

SMALL CREEKS AND STREAMS WILL RAPIDLY FLOOD...POSSIBLY OVERRUNNING 
ROADS AND FLOODING NEARBY LOW AREAS.

ABSOLUTELY DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER
COVERS THE ROADWAY. VEHICLES CAUGHT IN RISING WATER SHOULD BE
ABANDONED. MOVE TO HIGHER GROUND.

$$

LAT...LON 3624 8005 3606 8005 3606 8046 3624 8042

28
1 follow-up statement
000 
WGUS72 KRAH 182107
FFSRAH
NCC067-182230-

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE RALEIGH NC
459 PM EDT WED SEP 18 2002

...A FLASH FLOOD WARNING CONTINUES IN EFFECT FOR FORSYTH COUNTY 
INCLUDING WINSTON-SALEM UNTIL 630 PM THIS EVENING.

FLASH FLOODING HAS HAS ALREADY BEEN REPORTED ON SEVERAL HIGHWAYS... 
MOST NOTEABLY HIGHWAYS 52 AND 65 NORTHWEST OF WINSTON SALEM.  MILL 
CREEK AND MUDDY CREEK ARE LIKELY TO EXPERIENCE FLASH FLOODING.  
PEOPLE ALONG THESE CREEKS SHOULD TAKE ACTION AND SEEK HIGHER 
GROUND.

STORMS WILL CONTINUE TO PRODUCE VERY HEAVY RAIN DURING THE COMMUTER 
RUSH HOUR IN AND AROUND WINSTON SALEM.  HEAVY RAINS MAY FLOOD 
INTERSECTIONS...DITCHES AND UNDERPASSES. DO NOT ATTEMPT TO DRIVE 
THROUGH AREAS WHERE WATER COVERS THE ROADWAY.

MOST DEATHS IN FLASH FLOODING OCCUR IN AUTOMOBILES. DO NOT ATTEMPT TO
CROSS BRIDGES...DIPS...OR LOW SPOTS IF WATER COVERS THE ROADWAY.
NEVER TRY TO CROSS A FLOWING STREAM...EVEN A SMALL ONE...ON FOOT.

$$
28

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 18, 12:16 PM EDTFlash Flood WarningRAHCumberland59 min
Sep 18, 12:29 PM EDTFlash Flood WarningRAHChatham61 min
Sep 18, 2:42 PM EDTFlash Flood WarningRAHRandolph108 min
Sep 18, 2:55 PM EDTFlash Flood WarningRAHGuilford110 min
Sep 18, 3:04 PM EDTFlash Flood WarningRAHRandolph116 min
Sep 18, 4:52 PM EDTFlash Flood WarningRAHRandolph98 min
Sep 18, 5:21 PM EDTFlash Flood WarningRAHDavidson99 min
Sep 18, 5:37 PM EDTFlash Flood WarningRAHMontgomery83 min
Sep 18, 5:51 PM EDTFlash Flood WarningRAHStanly84 min
Sep 18, 6:26 PM EDTFlash Flood WarningRAHForsyth94 min

Nearby

Flash Flood Warnings in North Carolina, 2002Every flash flood warning in 2002

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.