Alert archive / Virginia / Flash Flood Warnings in 2021

Flash Flood Warning 15, NWS Blacksburg, VA

July 10, 2021Montgomery County, City of Radford, Virginia

NWS Blacksburg, VA issued this flash flood warning at Jul 10, 2021, 4:57 PM EDT for Montgomery County, City of Radford, Virginia. It was in force for 53 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Jul 10, 2021, 4:57 PM EDT (20:57 UTC)
Expired: Jul 10, 2021, 5:50 PM EDT
In force: 53 min
Issued by: NWS Blacksburg, VA
Area: Storm-based polygon
Flood severity: None

Counties City of Radford, VA, Montgomery County, VA

The radar

The Roanoke radar (KFCX), 24 km from the middle of the area, began a volume at 20:58 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, 9.0 hours before the alert went out and 86 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: 1182 m above ground
0-6 km bulk shear: 21 kt
0-1 km storm-relative helicity: -38 m²/s²
0-3 km storm-relative helicity: 6 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -0.0

Open this sounding in Storm Lab

The text

As transmitted.

282 
WGUS51 KRNK 102057
FFWRNK
VAC121-750-102300-
/O.NEW.KRNK.FF.W.0015.210710T2057Z-210710T2300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Blacksburg VA
457 PM EDT Sat Jul 10 2021

The National Weather Service in Blacksburg has issued a

* Flash Flood Warning for...
  Central Montgomery County in southwestern Virginia...
  The City of Radford in southwestern Virginia...

* Until 700 PM EDT.

* At 457 PM EDT, Doppler radar indicated thunderstorms producing 
  heavy rain from Radford to Blacksburg. Between 0.5 and 1 inch of 
  rain has fallen in less than 30 minutes. The expected rainfall 
  rate is 0.5 to 0.75 inches in 30 minutes. Additional rainfall 
  amounts of 1 to 1.5 inches are possible in the warned area. The 
  ground is saturated in this area from previous heavy rainfall in 
  the last week.  Flash flooding is ongoing or expected to begin 
  shortly.

  HAZARD...Flash flooding caused by thunderstorms.

  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...
  Blacksburg...                      Christiansburg...
  Radford...                         Merrimac...
  Walton...                          Fairlawn...

This includes the following locations...
	Virginia Tech.

This includes the following streams and drainages...
  Mill Creek, Connellys Run, Dry Run, Meadow Creek, Indian Run, Crab 
  Creek, New River, Flatwoods Branch, North Fork Roanoke River and 
  Little River.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Be aware of your surroundings and do not drive on flooded roads.

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 3711 8059 3714 8056 3715 8055 3714 8053
      3715 8053 3717 8056 3718 8053 3722 8048
      3729 8031 3725 8023 3724 8023 3722 8027
      3711 8048 3709 8058

FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL...0.5-0.75 INCHES IN 30 MINUTES

$$

RAB

1 follow-up statement

434 
WGUS71 KRNK 102150
FFSRNK

Flash Flood Statement
National Weather Service Blacksburg VA
550 PM EDT Sat Jul 10 2021

VAC121-750-102200-
/O.CAN.KRNK.FF.W.0015.000000T0000Z-210710T2300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Montgomery VA-City of Radford VA-
550 PM EDT Sat Jul 10 2021

...FLASH FLOOD WARNING IS CANCELLED FOR CENTRAL MONTGOMERY COUNTY 
AND THE CITY OF RADFORD...

The heavy rain has ended. Flooding is no longer expected to pose a 
threat. Please continue to heed remaining road closures and be aware 
that some poor drainage areas and low-lying areas may remain flooded 
for a bit longer.

LAT...LON 3711 8059 3714 8056 3715 8055 3714 8053
      3715 8053 3717 8056 3718 8053 3722 8048
      3729 8031 3725 8023 3724 8023 3722 8027
      3711 8048 3709 8058

$$

RAB

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 10, 1:49 PM EDT	Special Weather Statement	RNK	City of Galax	26 min
Jul 10, 1:51 PM EDT	Special Weather Statement	RNK	Smyth	24 min
Jul 10, 2:30 PM EDT	Special Weather Statement	RNK	Patrick	45 min
Jul 10, 2:36 PM EDT	Special Weather Statement	RNK	Bland, Tazewell	39 min
Jul 10, 3:18 PM EDT	Special Weather Statement	RNK	Bland	42 min
Jul 10, 4:03 PM EDT	Special Weather Statement	RNK	Craig, Giles	57 min
Jul 10, 4:42 PM EDT	Special Weather Statement	RNK	Alleghany, Botetourt, Carroll, Craig, Floyd, Giles and 9 more	63 min
Jul 10, 4:49 PM EDT	Areal Flood Advisory	RNK	Craig, Floyd, Giles, Montgomery, Pulaski, Roanoke and 1 more	2 hr
Jul 10, 5:05 PM EDT	Severe Thunderstorm Warning	RNK	Tazewell	55 min
Jul 10, 5:18 PM EDT	Areal Flood Advisory	RNK	Roanoke, City of Salem	101 min
Jul 10, 5:25 PM EDT	Areal Flood Advisory	RNK	Botetourt, Craig, Roanoke	95 min
Jul 10, 5:48 PM EDT	Areal Flood Advisory	RNK	Bedford, Botetourt, Roanoke, City of Roanoke	117 min
Jul 10, 6:16 PM EDT	Severe Thunderstorm Warning	RNK	Bedford	59 min
Jul 10, 6:46 PM EDT	Flash Flood Warning	RNK	Bedford	2 hr
Jul 10, 7:12 PM EDT	Areal Flood Warning	RNK	Bland, Carroll, Grayson, Pulaski, Smyth, Tazewell and 1 more	3 hr
Jul 10, 7:52 PM EDT	Special Weather Statement	RNK	Pulaski	38 min

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.