Alert archive / Virginia / Flash Flood Warnings in 1990

Flash Flood Warning 8, NWS Blacksburg, VA

July 17, 1990Montgomery County, Virginia

NWS Blacksburg, VA issued this flash flood warning at Jul 17, 1990, 11:02 PM EDT for Montgomery County, Virginia. It was in force for 58 min.

The area

The counties it named.

The facts

Issued
Jul 17, 1990, 11:02 PM EDT (03:02 UTC)
Expired
Jul 18, 1990, 12:00 AM EDT
In force
58 min
Issued by
NWS Blacksburg, VA
Area
Whole counties

County Montgomery 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 00:00Z, 3.0 hours before the alert went out and 129 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 00:00Z on 1990-07-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1617 joules per kilogram.LCLEL10008507005003002001001 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 00:00Z on 1990-07-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 48 square meters per square second.193958Sfc1 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
1617 J/kg
Mixed-layer CIN
-9 J/kg
Mixed-layer LCL
1188 m above ground
0-6 km bulk shear
26 kt
0-1 km storm-relative helicity
48 m²/s²
0-3 km storm-relative helicity
79 m²/s²
Significant tornado parameter
0.3
Supercell composite
3.2

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KROA 180302
FFWROA
VAC121-180500-
 
BULLETIN - EBS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE ROANOKE VA
1102 PM EDT TUE JUL 17 1990
 
THE NATIONAL WEATHER SERVICE IN ROANOKE VAHAS ISSUED A
FLASH FLOOD WARNING EFFECTIVE UNTIL  100 AM EDT
FOR PEOPLE IN THE FOLLOWING LOCATION...
 
IN SOUTHWEST VIRGINIA
 
   ...MONTGOMERY COUNTY
 
AUTOMATED RAIN GAUGES IN NORTHERN MONTGOMERY COUNTY SHOWS OVER THREE
INCHES OF RAIN HAVE FALLEN IN A LITTLE OVER AN HOUR. THUNDERSTORMS
REMAIN NEARLY STATIONARY IN NORTHERN MONTGOMERY COUNTY.
 
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.
 
A FLASH FLOOD WARNING MEANS THAT FLOODING IS OCCURRING OR IS
IMMINENT.  MOST FLASH FLOOD DEATHS OCCUR IN AUTOMOBILES.  DO NOT
ATTEMPT TO CROSS BRIDGES...DIPS...OrR LOW SPOTS IF WATER COVERS
THE ROADWAY.  NEVER TRY TO CROSS A FLOWING STREAM...EVEN A SMALL
ONE...ON FOOT.  TO ESCAPE RISING WATER MOVE UP TO HIGHER GROUND.

What forecasters said that day

The local office's own words before this flash flood warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

In the hours before

Special weather statement, Jul 17, 9:11 PM EDT, 1 hour 51 minutes before
VAZALL-180300-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE ROANOKE VA
905 PM   EDT  TUE JUL 17 1990

AT 900 PM EDT RADAR SHOWS THUNDERSTORMS AT THE CRAIG MONTGOMERY
AND ROANOKE COUNTIES LINES. ALSO A STRONG THUNDERSTORM IN SOUTHERN
FRANKLIN COUNTY. THESE THUNDERSTORMS ARE MOVING VERY LITTLE AND
COULD HAVE SOME HEAVY DOWNPOURS ALONG WITH DANGEROUS LIGHTNING.

SINCE THE GROUND IS ALREADY SATURATED FROM THE RAINS SATURDAY
THESE THUNDERSTORMS COULD CAUSE SOME SMALL STREAM FLOODING ALONG
WITH SOME LOW AREA FLOODING.
CE
Special weather statement, Jul 17, 10:06 PM EDT, 56 minutes before
VAZALL-180400-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE ROANOKE VA
1000 PM EDT TUE JUL 17 1990

RADAR SHOWS THUNDERSTORMS INCREASING IN DEVELOPMENT IN SOUTHWEST
VIRGINIA. AT 1000 PM RADAR SHOWS SOME STRONG ONES IN CRAIG
ROANOKE MONTGOMERY FRANKLIN PATRICK NORTHWEST HENRY AND AMHERST
COUNTIES. AS THESE THUNDERSTORMS DEVELOP THEY ARE SHOWING VERY
LITTLE MOVEMENT. THIS COULD CAUSE SOME VERY HEAVY DOWNPOURS CAUSING
SOME SMALL STREAM FLOODING$ ALONG WITH FLOODING IN LOW AREAS.
ALSO THESE THUNDERSTORMS COULD PRODUCE SOME DANGEROUS LIGHTNING.
CE

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.