Alert archive / Virginia / Flash Flood Warnings in 1999

Flash Flood Warning 33, NWS Blacksburg, VA

September 9, 1999Amherst County, Virginia

NWS Blacksburg, VA issued this flash flood warning at Sep 9, 1999, 5:30 PM EDT for Amherst County, Virginia. It was in force for 2 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 9, 1999, 5:30 PM EDT (21:30 UTC)
Expired: Sep 9, 1999, 7:30 PM EDT
In force: 2 hr
Issued by: NWS Blacksburg, VA
Area: Whole counties

County Amherst County, VA

The radar

The Roanoke radar (KFCX), 119 km from the middle of the area, began a volume at 21:31 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

Roanoke, VA (KRNK), launched 12:00Z, 9.5 hours before the alert went out and 55 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: 372 J/kg
Mixed-layer CIN: -230 J/kg
Mixed-layer LCL: 1296 m above ground
0-6 km bulk shear: 30 kt
0-1 km storm-relative helicity: -11 m²/s²
0-3 km storm-relative helicity: 1 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -0.3

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KROA 092130
FFWRNK
VAC009-092330-

BULLETIN--IMMEDIATE BROADCAST REQUESTED
FLOOD WARNING FOR SMALL CREEKS AND STREAMS
NATIONAL WEATHER SERVICE BLACKSBURG VA
530 PM EDT THU SEP 9 1999

THE NATIONAL WEATHER SERVICE IN BLACKSBURG HAS ISSUED A

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

* UNTIL 730 PM EDT.

* AT 525 PM EDT... NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  A THUNDERSTORM WITH VERY HEAVY RAINFALL NEAR THE BUFFALO RIVER
  AREA FROM ORONOCO...SOUTH TO PEDLAR MILLS.  THE THUNDESTORM IS
  MOVING SLOWLY TO THE NORTHEAST


* RAIN AMOUNTS FROM THREE TO FOUR INCHES HAVE FALLEN IN AMHERST
  COUNTY SINCE 430 PM EDT.  FLOODING IS EXPECTED TO OCCUR ALONG,
  THE BUFFALO AND PEDLAR RIVERS. ADDITIONAL RAIN AMOUNTS FROM ONE
  TO TWO INCHES WILL FALL THROUGH 630 PM.


<< CALL TO ACTION >> DON'T DRIVE INTO AREAS WHERE WATER COVERS THE
ROAD!

.END/HH/KK

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 9, 2:45 PM EDT, 2 hours 45 minutes earlier.

Area forecast discussion, Sep 9, 2:45 PM EDT, 2 hours 45 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
245 PM EDT THU SEP 9 1999

TONIGHT...VERY SLOW MOVING CONVECTION FIRING AT TIME...WITH ONLY PEA
HAIL AT TIME REPORTED FROM ALLEGHANY AND FLOYD COUNTIES.  CAPES OVER
EASTERN PIEDMONT BEING LIMITED BY CONVECTION FIRING OFF OF OUTER
BANKS.  EXPECT THIS TO CHANGE AFTER 00Z...AS VORT NOW OVER NORTHERN
ALABAMA ROTATES OVER PIEDMONT. BOTH NGM AND ETA SHOWING THIS. LIKELY
POPS LOOK GOOD IN EVENING PERIOD FROM NEW RIVER VALLEY EAST.

SHARP MOISTURE BOUNDARY WILL MOVE ACROSS AREA AFTER 06Z AS UPPER VORT
MOVES INTO WV AT 12Z AND ACROSS WESTERN VA LATE FRIDAY EVENING. NOT
TOO DRAMATIC A COOL DOWN ALOFT.  WITH LOSS OF MOISTURE...WILL TAKE
OUT POPS FOR TOMORROW MORNING IN SE WV AND NEW RIVER VALLEY.  COULD
BE A MISTAKE...BUT BELIEVE THIS IS A CASE WHERE THERE WILL BE NO
LEFT OVER SHOWERS.

IN EXTENDED...WILL BE INTERESTING TO SEE WHAT WILL HAPPEN WITH
FLOYD. IN ANY CASE...THE BLACKSBURG CWA SHOULD REMAIN DRY WITH TEMPS
REBOUNDING BY SUNDAY.

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

HH

The office that day

Everything else NWS Blacksburg, VA issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Sep 9, 1:56 PM EDT	Severe Thunderstorm Warning	RNK	Floyd	49 min
Sep 9, 2:16 PM EDT	Flash Flood Warning	RNK	Floyd	4 hr
Sep 9, 2:40 PM EDT	Severe Thunderstorm Warning	RNK	Roanoke	65 min
Sep 9, 3:08 PM EDT	Flash Flood Warning	RNK	Patrick	2 hr
Sep 9, 4:37 PM EDT	Severe Thunderstorm Warning	RNK	Rockbridge, City of Buena Vista, City of Lexington	48 min

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; radar from the NEXRAD Level II archive.