Alert archive / Virginia / Flash Flood Watches in 2018

Flash Flood Watch 10, NWS Blacksburg, VA

September 1, 201823 counties in Virginia

NWS Blacksburg, VA issued this flash flood watch at Sep 1, 2018, 12:24 PM EDT for 23 counties in Virginia. It was in force for 8 hr.

The area

The counties it named.

The facts

Issued: Sep 1, 2018, 12:24 PM EDT (16:24 UTC)
Expired: Sep 1, 2018, 8:13 PM EDT
In force: 8 hr
Issued by: NWS Blacksburg, VA
Flood severity: None

All 23 counties

Amherst County, VA, Appomattox County, VA, Bath County, VA, Bedford County, VA, Botetourt County, VA, Buckingham County, VA, Campbell County, VA, Carroll County, VA, City of Buena Vista, VA, City of Galax, VA, City of Lexington, VA, City of Lynchburg, VA, City of Martinsville, VA, City of Roanoke, VA, City of Salem, VA, Floyd County, VA, Franklin County, VA, Grayson County, VA, Henry County, VA, Montgomery County, VA, Patrick County, VA, Roanoke County, VA, Rockbridge County, VA

The radar

The Roanoke radar (KFCX), 47 km from the middle of the area, began a volume at 16:28 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, 4.4 hours before the alert went out and 28 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: 277 J/kg
Mixed-layer CIN: -58 J/kg
Mixed-layer LCL: 897 m above ground
0-6 km bulk shear: 11 kt
0-1 km storm-relative helicity: 65 m²/s²
0-3 km storm-relative helicity: 36 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this flash flood watch 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 watch went out at Sep 1, 7:08 AM EDT, 5 hours 16 minutes earlier.

Area forecast discussion, Sep 1, 7:08 AM EDT, 5 hours 16 minutes before

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Hazardous weather outlook, Sep 1, 6:50 AM EDT, 5 hours 34 minutes before

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In the hours before

Local storm report, Sep 1, 10:00 AM EDT, 2 hours 24 minutes before

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Local storm report, Sep 1, 10:18 AM EDT, 2 hours 6 minutes before

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Local storm report, Sep 1, 10:35 AM EDT, 1 hour 49 minutes before

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Local storm report, Sep 1, 11:14 AM EDT, 1 hour 10 minutes before

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Local storm report, Sep 1, 11:45 AM EDT, 39 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BLACKSBURG VA
1145 AM EDT SAT SEP 1 2018

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0250 PM     TSTM WND DMG     5 S SPEEDWELL           36.75N 81.16W
08/31/2018                   GRAYSON            VA   TRAINED SPOTTER

            LARGE TREE LIMBS DOWN ON HWY 21

&&

AMS

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 31, 11:05 PM EDT	Special Weather Statement	RNK	Henry	25 min
Aug 31, 11:32 PM EDT	Special Weather Statement	RNK	Henry	28 min
Sep 1, 12:05 AM EDT	Special Weather Statement	RNK	Henry, City of Martinsville	55 min
Sep 1, 12:10 AM EDT	Severe Thunderstorm Warning	RNK	Floyd, Franklin, Henry, Patrick	65 min
Sep 1, 12:24 AM EDT	Areal Flood Advisory	RNK	Franklin, Henry, Patrick	3 hr
Sep 1, 12:25 AM EDT	Areal Flood Advisory	RNK	Henry	3 hr
Sep 1, 12:45 AM EDT	Special Weather Statement	RNK	City of Martinsville	45 min
Sep 1, 12:47 AM EDT	Special Weather Statement	RNK	Franklin	43 min
Sep 1, 12:57 AM EDT	Flash Flood Warning	RNK	Franklin, Henry, Patrick	5 hr
Sep 1, 1:06 AM EDT	Severe Thunderstorm Warning	RNK	Franklin	54 min
Sep 1, 1:21 AM EDT	Flash Flood Warning	RNK	Henry, Pittsylvania	6 hr
Sep 1, 1:39 AM EDT	Special Weather Statement	RNK	Henry, Patrick	36 min
Sep 1, 1:51 AM EDT	Special Weather Statement	RNK	City of Danville	39 min
Sep 1, 2:01 AM EDT	Special Weather Statement	RNK	Franklin	44 min
Sep 1, 2:08 AM EDT	Severe Thunderstorm Warning	RNK	Pittsylvania, City of Danville	24 min
Sep 1, 2:17 AM EDT	Areal Flood Warning	RNK	Bedford, Franklin, Pittsylvania	4 hr
Sep 1, 2:19 AM EDT	Areal Flood Advisory	RNK	Pittsylvania	2 hr
Sep 1, 2:30 AM EDT	Special Weather Statement	RNK	Carroll	45 min
Sep 1, 3:01 AM EDT	Special Weather Statement	RNK	Bedford, Campbell, City of Lynchburg	44 min
Sep 1, 3:18 AM EDT	Areal Flood Advisory	RNK	Carroll, Floyd, Patrick	88 min
Sep 1, 3:26 AM EDT	Areal Flood Advisory	RNK	Henry, Patrick, City of Martinsville	3 hr
Sep 1, 3:53 AM EDT	Areal Flood Advisory	RNK	Patrick	3 hr
Sep 1, 4:21 AM EDT	Flash Flood Warning	RNK	Henry, City of Martinsville	3 hr
Sep 1, 1:43 PM EDT	Special Weather Statement	RNK	City of Roanoke	62 min
Sep 1, 2:18 PM EDT	Special Weather Statement	RNK	Henry	57 min
Sep 1, 2:26 PM EDT	Special Weather Statement	RNK	Bedford, Botetourt, Rockbridge, City of Buena Vista, City of Lexington	64 min
Sep 1, 2:39 PM EDT	Special Weather Statement	RNK	Franklin	66 min
Sep 1, 2:46 PM EDT	Areal Flood Advisory	RNK	Carroll, Grayson, City of Galax	3 hr
Sep 1, 3:07 PM EDT	Special Weather Statement	RNK	Floyd	68 min
Sep 1, 3:31 PM EDT	Flash Flood Warning	RNK	Carroll, City of Galax	2 hr
Sep 1, 3:40 PM EDT	Special Weather Statement	RNK	Pittsylvania	50 min
Sep 1, 3:47 PM EDT	Areal Flood Advisory	RNK	Amherst, Rockbridge, City of Buena Vista	3 hr
Sep 1, 3:50 PM EDT	Special Weather Statement	RNK	Franklin	55 min
Sep 1, 3:56 PM EDT	Flash Flood Warning	RNK	Amherst, Rockbridge, City of Buena Vista	3 hr
Sep 1, 4:04 PM EDT	Special Weather Statement	RNK	Appomattox, Buckingham	56 min
Sep 1, 4:05 PM EDT	Severe Thunderstorm Warning	RNK	Henry, City of Martinsville	55 min
Sep 1, 4:11 PM EDT	Special Weather Statement	RNK	Charlotte, Halifax	64 min
Sep 1, 4:38 PM EDT	Special Weather Statement	RNK	Amherst, Campbell, Charlotte, Halifax, Pittsylvania, City of Danville and 1 more	67 min
Sep 1, 4:51 PM EDT	Areal Flood Advisory	RNK	Henry, Patrick	3 hr
Sep 1, 5:10 PM EDT	Severe Thunderstorm Warning	RNK	Halifax, Pittsylvania, City of Danville	65 min
Sep 1, 5:25 PM EDT	Flash Flood Warning	RNK	Appomattox, Campbell, Charlotte, Halifax	3 hr
Aug 31, 8:00 PM EDT	Special Weather Statement	RNK	Wilkes	60 min
Aug 31, 11:25 PM EDT	Areal Flood Advisory	RNK	Rockingham	35 min
Aug 31, 11:58 PM EDT	Flash Flood Warning	RNK	Rockingham	6 hr
Sep 1, 12:16 AM EDT	Severe Thunderstorm Warning	RNK	Rockingham, Stokes	59 min
Sep 1, 5:00 PM EDT	Special Weather Statement	RNK	Caswell	60 min
Sep 1, 5:32 PM EDT	Severe Thunderstorm Warning	RNK	Rockingham, Stokes	58 min

Nearby

Flash Flood Watches in Virginia, 2018 Every flash flood watch in 2018

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.