Alert archive / Virginia / Flash Flood Warnings in 1990

Flash Flood Warning 9, NWS Blacksburg, VA

July 20, 1990Botetourt County, Virginia

NWS Blacksburg, VA issued this flash flood warning at Jul 20, 1990, 6:59 PM EDT for Botetourt County, Virginia. It was in force for 61 min.

The area

The counties it named.

The facts

Issued
Jul 20, 1990, 6:59 PM EDT (22:59 UTC)
Expired
Jul 20, 1990, 8:00 PM EDT
In force
61 min
Issued by
NWS Blacksburg, VA
Area
Whole counties

County Botetourt County, VA

The radar

The WSR-88D network and its archive begin in 1991, so there is no radar volume for this alert.

The nearest sounding before it

Greensboro/Hi Pt, NC (KGSO), launched 12:00Z, 11.0 hours before the alert went out and 164 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 1990-07-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1569 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 1990-07-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 66 square meters per square second.1939Sfc1 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
1569 J/kg
Mixed-layer CIN
-35 J/kg
Mixed-layer LCL
830 m above ground
0-6 km bulk shear
19 kt
0-1 km storm-relative helicity
66 m²/s²
0-3 km storm-relative helicity
60 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 KROA 202300
FFWROA
VAC023-210000-
 
BULLETIN - EBS ACTIVATION REQUESTED
SMALL STREAM AND URBAN FLOOD WARNING
NATIONAL WEATHER SERVICE ROANOKE VA
659 PM EDT FRI JUL 20 1990
 
THE NATIONAL WEATHER SERVICE IN ROANOKE VAHAS ISSUED A
SMALL STREAM AND URBAN FLOOD WARNING EFFECTIVE UNTIL  800 PM EDT
FOR PEOPLE IN THE FOLLOWING LOCATION...
 
IN SOUTHWEST VIRGINIA
 
   ...NORTH CENTRAL BOTETOURT COUNTY
 
AT 650 PM EDT...WEATHER RADAR INDICATES A STORM PRODUCING VERY HEAVY
RAINFALL IN THE NORTH CENTRAL PORTION OF BOTETOURT COUNTY. IFLOWS RAIN
GAUGE AT SLOAN BRANCH SHOWS 1.90 INCHES OF RAIN AS FALLEN SINCE 600
PM. SLOAN BRANCH IS 5 MILES EAST OF THE TOWN OF GALA.
 
 
BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE
THE DANGERS OF FLOODS AND FLASH FLOODS.  IF FLASH FLOODING IS
OBSERVED...ACT QUICKLY.  MOVE UP TO ESCAPE FLOOD WATERS.  DO
NOT STAY IN AREAS SUBJECT TO FLOODING WHEN WATER BEGINS RISING.
 
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.
 
CACCIAPAGLIA

Nearby

Flash Flood Warnings in Virginia, 1990Every flash flood warning in 1990

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.