Alert archive / North Carolina / Flash Flood Warnings in 1998

Flash Flood Warning 24, NWS Raleigh, NC

April 17, 1998Forsyth County, North Carolina

NWS Raleigh, NC issued this flash flood warning at Apr 17, 1998, 5:59 PM EDT for Forsyth County, North Carolina. It was in force for 3 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
Apr 17, 1998, 5:59 PM EDT (21:59 UTC)
Expired
Apr 17, 1998, 9:00 PM EDT
In force
3 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 22:00 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, 10.0 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 1998-04-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 77 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 1998-04-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 277 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
77 J/kg
Mixed-layer CIN
-98 J/kg
Mixed-layer LCL
541 m above ground
0-6 km bulk shear
61 kt
0-1 km storm-relative helicity
277 m²/s²
0-3 km storm-relative helicity
274 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 
TTAA00 KRDU 172200
FFWRDU
NCC067-180100-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE RALEIGH NC
559 PM EDT FRI APR 17 1998

THE NATIONAL WEATHER SERVICE IN RALEIGH HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  FORSYTH COUNTY

* UNTIL 900 PM EDT

* AT 600 PM EDT... SPOTTERS INDICATED HEAVY RAIN NEAR REYNOLDA ROAD
  AND PFAFFTOWN... MOVING NORTHEAST AT 15 MPH.

* YADKIN RIVER IN FORSYTH COUNTY IS OUT OF ITS BANKS. SPOTTERS IN
  FORSYTH CONFIRM THIS AND RADAR INDICATES THAT STORMS BRINGING
  ABOUT AN INCH OF NEW RAIN IN THE NEXT HOUR.

DON'T DRIVE INTO AREAS WHERE WATER COVERS THE ROAD!

JWC

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 17, 6:05 PM EDTSevere Thunderstorm WarningRAHForsyth60 min
Apr 17, 6:21 PM EDTSevere Thunderstorm WarningRAHDavidson59 min
Apr 17, 6:40 PM EDTSevere Thunderstorm WarningRAHGuilford, Randolph60 min
Apr 17, 6:55 PM EDTTornado WarningRAHGuilford65 min
Apr 17, 7:48 PM EDTSevere Thunderstorm WarningRAHAlamance47 min

Nearby

Flash Flood Warnings in North Carolina, 1998Every flash flood warning in 1998

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.