Alert archive / Virginia / Flash Flood Warnings in 1999

Flash Flood Warning 38, NWS Blacksburg, VA

September 21, 1999Halifax County, Virginia

NWS Blacksburg, VA issued this flash flood warning at Sep 21, 1999, 10:00 PM EDT for Halifax County, Virginia. It was in force for 4 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 21, 1999, 10:00 PM EDT (02:00 UTC)
Expired: Sep 22, 1999, 1:55 AM EDT
In force: 4 hr
Issued by: NWS Blacksburg, VA
Area: Whole counties

County Halifax County, VA

The nearest sounding before it

Roanoke, VA (KRNK), launched 00:00Z, 2.0 hours before the alert went out and 69 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 970 m above ground
0-6 km bulk shear: 30 kt
0-1 km storm-relative helicity: -35 m²/s²
0-3 km storm-relative helicity: 100 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 220201
FFWRNK
VAC083-220555-

BULLETIN--IMMEDIATE BROADCAST REQUESTED
FLOOD WARNING FOR SMALL CREEKS AND STREAMS
NATIONAL WEATHER SERVICE BLACKSBURG VA
1000 PM EDT TUE SEP 21 1999

THE NATIONAL WEATHER SERVICE IN BLACKSBURG HAS ISSUED A

* FLOOD WARNING FOR SMALL CREEKS AND STREAMS FOR...
  HALIFAX COUNTY IN SOUTH CENTRAL VIRGINIA.

* UNTIL 155 AM EDT.

* AT 1000 PM EDT...COUNTY EMERGENCY COORDINATORS REPORTED
  FLOODING ALONG THE HYCO RIVER IN THE SOUTHERN PART OF HALIFAX
  COUNTY...DUE TO HEAVY RAINFALL WHICH FELL BETWEEN 7 PM AND 10
  PM.  OVER SOUTHERN HALIFAX COUNTY...THE HYCO RIVER AND ITS
  TRIBUTARIES HAVE FLOODED SEVERAL ROADS...INCLUDING PORTIONS OF
  STATE ROUTE 96.

* THE HEAVY RAIN HAS ENDED ACROSS THIS AREA...HOWEVER FLOODING IS
  EXPECTED TO CONTINUE INTO THE EARLY MORNING HOURS.

<< CALL TO ACTION >> DO NOT DRIVE WHERE WATER COVERS THE ROADWAY. BE
  ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE
  DANGER OF FfLOODING.

.END/JDS

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.

NWS Blacksburg, VA wrote its last area forecast discussion before this flash flood warning went out at Sep 21, 9:00 PM EDT, 1 hour earlier.

Area forecast discussion, Sep 21, 9:00 PM EDT, 1 hour before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
900 PM EDT TUE SEP 21 1999

STILL A GOOD BIT OF CLOUD COVER IN THE WAKE OF THE COLD FRONT WHICH
HAS NOW CLEARED THE CWA. SOME -RA IS STILL LINGERING OVER THE FAR
ERN COUNTIES...MAINLY EAST OF DANVILLE...AND WILL MODIFY THE FCST
ACCORDINGLY. CLEARING LINE TO OUR NW IS BETWEEN CRW AND BKW...AND
BASED ON SAT TRENDS THIS SHOULD REACH BLF AND LWB BTWN 06-08Z.

FCST SOUNDINGS FROM THE MESO-ETA FOR WEDNESDAY ARE DRY...BUT BASED
ON OBSERVED CONDITIONS UPSTREAM THIS AFTERNOON...SCT-BKN SC LIKELY
TO FORM...BUT MAINLY OVER THE MTN ZONES.

THIS AIRMASS IS A COOL ONE.  DEWPOINTS IN THE UPPER OHIO VALLEY ARE
IN THE LOW TO MID 30S.  IF WE MIX OUT AND GET CLOSE TO THESE NUMBERS
WEDNESDAY AFTN...COULD SEE SOME FROST WEDNESDAY NIGHT...BUT MAINLY
WEST OF THE BLUE RIDGE.

.RNK
VA...NONE.
WV...NONE.
NC...NONE.

PM

Nearby

Flash Flood Warnings in Virginia, 1999 Every flash flood warning in 1999

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.