Alert archive / North Carolina / Flash Flood Warnings in 2002

Flash Flood Warning 49, NWS Raleigh, NC

September 18, 2002Forsyth County, North Carolina

NWS Raleigh, NC issued this flash flood warning at Sep 18, 2002, 6:26 PM EDT for Forsyth County, North Carolina. It was in force for 94 min. 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, 6:26 PM EDT (22:26 UTC)
Expired
Sep 18, 2002, 8:00 PM EDT
In force
94 min
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 22:11 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, 10.4 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 182226
FFWRAH
NCC067-190000-

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

THE NATIONAL WEATHER SERVICE IN RALEIGH HAS EXTENDED A

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

* UNTIL 800 PM EDT

* AT 623 PM EDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED 
  HEAVY RAIN CONTINUING MAINLY OVER THE WESTERN HALF OF FORSYTH 
  COUNTY...INCLUDING LEWISVILLE AND CLEMMONS. 

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

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.

A FLASH FLOOD WARNING MEANS THAT FLOODING IS OCCURRING OR IS
IMMINENT. NEVER ATTEMPT TO CROSS HIGH WATER IN A VEHICLE OR ON FOOT

$$

LAT...LON 3624 8021 3601 8021 3598 8039 3608 8047
          3624 8043

28
1 follow-up statement
000 
WGUS72 KRAH 190011
FFSRAH
NCC067-190100-

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

THE FLASH FLOOD WARNING IN EFFECT EARLIER THIS EVENING FOR FORSYTH 
COUNTY HAS NOW EXPIRED.  

HEAVY RAINS HAVE TAPERED OFF TO MOSTLY LIGHT SHOWERS AND CREEK 
LEVELS ARE RECEDING.  HOWEVER...WATER MAY YET BE COVERING SOME ROADS 
IN THE WESTERN PART OF THE COUNTY...PARTICULARLY AROUND PFAFFTOWN.

RADAR ESTIMATES SHOW THAT THREE TO SIX INCHES OF RAIN HAS FALLEN 
SINCE 400 PM THIS AFTERNOON ACROSS A LARGE PORTION OF CENTRAL AND 
WESTERN FORSYTH COUNTY.  THE HEAVIEST APPEAR TO HAVE OCCURRED FROM 
NEAR LEWISVILLE AND PFAFFTOWN TO NEAR STANLEYVILLE...NORTH AND WEST 
OF WINSTON-SALEM.

SOME ROADS HAVE BEEN FLOODED AND MAY CONTINUE TO BE IMPASSABLE UNTIL 
WATERS RECEDE LATER THIS EVENING. IN PARTICULAR... CONRAD... 
SAWMILL...GRAPEVINE...AND ROBINHOOD ROADS...ALL NEAR PFAFFTOWN HAVE 
HAD REPORTS OF FLOODING.

DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE
ROADWAY. THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO CROSS
SAFELY. VEHICLES CAUGHT IN RISING WATER SHOULD BE ABANDONED QUICKLY.
MOVE TO HIGHER GROUND.

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE 
DANGERS OF WATER ON HIGHWAYS. 

$$
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, 4:30 PM EDTFlash Flood WarningRAHForsyth2 hr
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

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.