Alert archive / Virginia / Flash Flood Warnings in 2021

Flash Flood Warning 40, NWS Blacksburg, VA

September 22, 20214 counties in Virginia

NWS Blacksburg, VA issued this flash flood warning at Sep 22, 2021, 4:53 PM EDT for 4 counties in Virginia. It was in force for 4 hr. 4 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: Sep 22, 2021, 4:53 PM EDT (20:53 UTC)
Expired: Sep 22, 2021, 8:45 PM EDT
In force: 4 hr
Issued by: NWS Blacksburg, VA
Area: Storm-based polygon
Flood severity: None

Counties Bedford County, VA, Franklin County, VA, Patrick County, VA, Roanoke County, VA

The radar

The Roanoke radar (KFCX), 24 km from the middle of the area, began a volume at 20:57 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.

What was reported inside it

Time	Report	Where	Remark
Sep 22, 6:00 PM EDT	FLASH FLOOD	2 Ene Montvale, VA	DRY CREEK FLOODED BEALE TRAIL ROAD.
Sep 22, 6:00 PM EDT	FLASH FLOOD	Montvale, VA	HIGH WATER CLOSED US 221/ROUTE 460.
Sep 22, 6:11 PM EDT	FLOOD	Montvale, VA	FLOODING ALONG U.S. 460.
Sep 22, 6:40 PM EDT	FLASH FLOOD	2 Nne Montvale, VA	CULVERT WASHED OUT ON CROUCH ROAD BY TRIBUTARY OF GOOSE CREEK.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Roanoke, VA (KRNK), launched 12:00Z, 8.9 hours before the alert went out and 64 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: 266 J/kg
Mixed-layer CIN: -2 J/kg
Mixed-layer LCL: 555 m above ground
0-6 km bulk shear: 24 kt
0-1 km storm-relative helicity: 97 m²/s²
0-3 km storm-relative helicity: 119 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 0.6

Open this sounding in Storm Lab

The text

As transmitted.

262 
WGUS51 KRNK 222053
FFWRNK
VAC019-067-141-161-230045-
/O.NEW.KRNK.FF.W.0040.210922T2053Z-210923T0045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Blacksburg VA
453 PM EDT Wed Sep 22 2021

The National Weather Service in Blacksburg has issued a

* Flash Flood Warning for...
  West Central Bedford County in south central Virginia...
  Eastern Patrick County in southwestern Virginia...
  Central Franklin County in west central Virginia...
  Southeastern Roanoke County in west central Virginia...

* Until 845 PM EDT.

* At 453 PM EDT, Doppler radar and automated rain gauges indicated 
  thunderstorms producing heavy rain across the warned area. Up to 3 
  inches of rain have fallen. The expected rainfall rate is 4 inches 
  in 1 hour. Flash flooding is ongoing or expected to begin shortly.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Radar and automated gauges.

  IMPACT...Flash flooding of small creeks and streams, urban
           areas, highways, streets and underpasses as well as
           other poor drainage and low-lying areas.

* Some locations that will experience flash flooding include...
   Vinton...                          Rocky Mount...
  Stuart...                          Boones Mill...
  Ferrum...                          Woolwine...
  Stewartsville...

This includes the following streams and drainages...
  Blackberry Creek, Blackwater River, Boothe Creek, Archies Creek, 
  Big Otter River, Bore Auger Creek, Back Creek and Anglin Branch.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood 
deaths occur in vehicles.

In hilly terrain there are hundreds of low water crossings which are 
potentially dangerous in heavy rain. Do not attempt to cross flooded 
roads. Find an alternate route.

When it is safe to do so, please send your reports of flooding, 
including mudslides or flooded roads, to the National Weather 
Service by calling toll free at 1...8 6 6...2 1 5...4 3 2 4. Reports 
and pictures can also be shared on the National Weather Service 
Blacksburg Facebook page and on Twitter.

&&

LAT...LON 3654 8045 3700 8012 3744 7970 3739 7959
      3679 8006 3678 8009 3674 8009 3654 8025

FLASH FLOOD...RADAR AND GAUGE INDICATED
EXPECTED RAINFALL...4 INCHES IN 1 HOUR

$$

WP

2 follow-up statements

835 
WGUS71 KRNK 222213
FFSRNK

Flash Flood Statement
National Weather Service Blacksburg VA
613 PM EDT Wed Sep 22 2021

VAC019-067-141-161-230045-
/O.CON.KRNK.FF.W.0040.000000T0000Z-210923T0045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Bedford VA-Franklin VA-Patrick VA-Roanoke VA-
613 PM EDT Wed Sep 22 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 845 PM EDT THIS 
EVENING FOR WEST CENTRAL BEDFORD, EASTERN PATRICK, CENTRAL FRANKLIN 
AND SOUTHEASTERN ROANOKE COUNTIES...

At 613 PM EDT, Doppler radar and automated rain gauges indicated 
thunderstorms producing heavy rain across the warned area. Between 1 
and 4 inches of rain have fallen. Flash flooding is ongoing or 
expected to begin shortly.

HAZARD...Flash flooding caused by thunderstorms.

SOURCE...Radar and automated gauges.

IMPACT...Flash flooding of small creeks and streams, urban areas,
         highways, streets and underpasses as well as other poor
         drainage and low-lying areas.

Some locations that will experience flash flooding include...
  Vinton...                          Rocky Mount...
Stuart...                          Boones Mill...
Ferrum...                          Woolwine...
Stewartsville...

This includes the following streams and drainages...
  Blackberry Creek, Blackwater River, Boothe Creek, Archies Creek, 
  Big Otter River, Bore Auger Creek, Back Creek and Anglin Branch.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood 
deaths occur in vehicles.

In hilly terrain there are hundreds of low water crossings which are 
potentially dangerous in heavy rain. Do not attempt to cross flooded 
roads. Find an alternate route.

When it is safe to do so, please send your reports of flooding, 
including mudslides or flooded roads, to the National Weather 
Service by calling toll free at 1...8 6 6...2 1 5...4 3 2 4. Reports 
and pictures can also be shared on the National Weather Service 
Blacksburg Facebook page and on Twitter.

&&

LAT...LON 3654 8045 3700 8012 3744 7970 3739 7959
      3679 8006 3678 8009 3674 8009 3654 8025

FLASH FLOOD...RADAR AND GAUGE INDICATED

$$

BMG

028 
WGUS71 KRNK 230035
FFSRNK

Flash Flood Statement
National Weather Service Blacksburg VA
835 PM EDT Wed Sep 22 2021

VAC019-067-141-161-230045-
/O.EXP.KRNK.FF.W.0040.000000T0000Z-210923T0045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Bedford VA-Franklin VA-Patrick VA-Roanoke VA-
835 PM EDT Wed Sep 22 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 845 PM EDT THIS EVENING FOR 
WEST CENTRAL BEDFORD, EASTERN PATRICK, CENTRAL FRANKLIN AND 
SOUTHEASTERN ROANOKE COUNTIES...

Flooding is no longer expected to pose a threat. Please continue to 
heed remaining road closures.

A Flash Flood Watch remains in effect until 800 AM EDT Thursday for 
portions of north central North Carolina and Virginia.

LAT...LON 3654 8045 3700 8012 3744 7970 3739 7959
      3679 8006 3678 8009 3674 8009 3654 8025

$$

BMG

The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 21, 8:07 PM EDT	Areal Flood Advisory	RNK	Floyd, Franklin	3 hr
Sep 21, 9:00 PM EDT	Areal Flood Advisory	RNK	Floyd, Franklin, Montgomery, Roanoke, City of Roanoke, City of Salem	3 hr
Sep 21, 9:34 PM EDT	Areal Flood Advisory	RNK	Carroll, Floyd, Patrick	3 hr
Sep 21, 10:10 PM EDT	Flash Flood Warning	RNK	Carroll, Floyd, Patrick	6 hr
Sep 21, 10:19 PM EDT	Areal Flood Advisory	RNK	Floyd, Patrick	3 hr
Sep 21, 11:25 PM EDT	Areal Flood Advisory	RNK	Floyd, Franklin	3 hr
Sep 21, 11:56 PM EDT	Areal Flood Advisory	RNK	Carroll, Floyd, Montgomery, Pulaski, City of Radford	6 hr
Sep 22, 12:20 AM EDT	Flash Flood Warning	RNK	Floyd, Patrick	4 hr
Sep 22, 1:00 AM EDT	Flash Flood Warning	RNK	Franklin, Roanoke, City of Roanoke, City of Salem	3 hr
Sep 22, 1:12 AM EDT	Flash Flood Warning	RNK	Montgomery	6 hr
Sep 22, 2:27 AM EDT	Flash Flood Warning	RNK	Craig, Giles	6 hr
Sep 22, 5:03 AM EDT	Areal Flood Advisory	RNK	Floyd, Franklin, Henry, Patrick	3 hr
Sep 22, 11:00 AM EDT	Areal Flood Advisory	RNK	Bedford, Botetourt, Floyd, Franklin, Henry, Patrick and 7 more	11 hr
Sep 22, 1:35 PM EDT	Special Weather Statement	RNK	City of Martinsville	25 min
Sep 22, 2:02 PM EDT	Special Weather Statement	RNK	Amherst	28 min
Sep 22, 2:52 PM EDT	Areal Flood Advisory	RNK	Craig, Giles, Montgomery, Pulaski, City of Radford	2 hr
Sep 22, 3:38 PM EDT	Special Weather Statement	RNK	Floyd, Montgomery	22 min
Sep 22, 4:01 PM EDT	Special Weather Statement	RNK	Patrick	29 min
Sep 22, 4:20 PM EDT	Special Weather Statement	RNK	Patrick	40 min
Sep 22, 4:27 PM EDT	Severe Thunderstorm Warning	RNK	Patrick	33 min
Sep 22, 4:35 PM EDT	Special Weather Statement	RNK	Franklin	40 min
Sep 22, 4:47 PM EDT	Special Weather Statement	RNK	Rockbridge, City of Buena Vista, City of Lexington	28 min
Sep 22, 5:32 PM EDT	Flash Flood Warning	RNK	Bedford, Botetourt, Rockbridge, City of Buena Vista, City of Lexington	3 hr
Sep 22, 7:10 PM EDT	Areal Flood Warning	RNK	Rockbridge	2 hr
Sep 22, 7:19 PM EDT	Areal Flood Advisory	RNK	Amherst	3 hr

Nearby

Flash Flood Warnings in Virginia, 2021 Every flash flood warning in 2021

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.