Alert archive / Virginia / Flash Flood Warnings in 2021

Flash Flood Warning 36, NWS Blacksburg, VA

September 22, 2021Floyd County, Patrick County, Virginia

NWS Blacksburg, VA issued this flash flood warning at Sep 22, 2021, 12:20 AM EDT for Floyd County, Patrick 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 outline as issued.

The facts

Issued: Sep 22, 2021, 12:20 AM EDT (04:20 UTC)
Expired: Sep 22, 2021, 3:57 AM EDT
In force: 4 hr
Issued by: NWS Blacksburg, VA
Area: Storm-based polygon
Flood severity: None

Counties Floyd County, VA, Patrick County, VA

The radar

The Roanoke radar (KFCX), 11 km from the middle of the area, began a volume at 04:19 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 00:00Z, 4.3 hours before the alert went out and 83 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: 475 m above ground
0-6 km bulk shear: 22 kt
0-1 km storm-relative helicity: 31 m²/s²
0-3 km storm-relative helicity: 211 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

256 
WGUS51 KRNK 220420
FFWRNK
VAC063-141-221030-
/O.NEW.KRNK.FF.W.0036.210922T0420Z-210922T1030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Blacksburg VA
1220 AM EDT Wed Sep 22 2021

The National Weather Service in Blacksburg has issued a

* Flash Flood Warning for...
  Central Floyd County in southwestern Virginia...
  North Central Patrick County in southwestern Virginia...

* Until 630 AM EDT Wednesday.

* At 1220 AM EDT, Doppler radar indicated persistent moderate to 
  heavy rainfall within the warned area. Between 2.5 and 4 inches of 
  rain have fallen during the past 6 hours. The expected rainfall 
  rate is 1 to 1.5 inches in 1 hour. Additional rainfall amounts of 
  1.5 to 3 inches are possible in the warned area. Flash flooding is 
  imminent.

  HAZARD...Flash flooding caused by heavy rain.

  SOURCE...Radar.

  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...
  Floyd...                           Woolwine...
  Rocky Knob Summit...               Rocky Knob Recreation Area...
  Buffalo Ridge...

This includes the following streams and drainages...
  Laurel Branch, Howell Creek, Huckleberry Creek, Dodd Creek, Dan 
  River, Jacks Creek, Joint Crack Creek, Little Sycamore Creek, East 
  Prong Furnace Creek, Little Creek, Brush Creek, Little River and 
  Beaver Creek.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Be especially cautious at night when it is harder to recognize the 
dangers of flooding.

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 3702 8045 3701 8044 3702 8043 3701 8042
      3700 8042 3701 8041 3702 8042 3702 8041
      3701 8040 3702 8038 3702 8034 3706 8031
      3677 8023 3669 8031 3701 8045

FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL...1-1.5 INCHES IN 1 HOUR

$$

RAB

1 follow-up statement

045 
WGUS71 KRNK 220757
FFSRNK

Flash Flood Statement
National Weather Service Blacksburg VA
357 AM EDT Wed Sep 22 2021

VAC063-141-220807-
/O.CAN.KRNK.FF.W.0036.000000T0000Z-210922T1030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Floyd VA-Patrick VA-
357 AM EDT Wed Sep 22 2021

...FLASH FLOOD WARNING IS CANCELLED FOR FLOYD AND NORTH CENTRAL 
PATRICK COUNTIES...

Rainfall has decreased within the warned area. Light rain continues 
and will continue across the warned area for several more hours, but 
the rainfall rates are expected to be insufficient to produce 
significant flooding or flash flooding. Please continue to heed 
remaining road closures.

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

LAT...LON 3702 8045 3701 8044 3702 8043 3701 8042
      3700 8042 3701 8041 3702 8042 3702 8041
      3701 8040 3702 8038 3702 8034 3706 8031
      3677 8023 3669 8031 3701 8045

$$

RAB

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, 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, 4:53 PM EDT	Flash Flood Warning	RNK	Bedford, Franklin, Patrick, Roanoke	4 hr
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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.