Alert archive / Virginia / Flash Flood Watches in 2018

Flash Flood Watch 7, NWS Blacksburg, VA

July 31, 201814 counties in Virginia; 8 counties in North Carolina

NWS Blacksburg, VA issued this flash flood watch at Jul 31, 2018, 3:46 AM EDT for 14 counties in Virginia; 8 counties in North Carolina. It took effect at Jul 31, 2018, 12:00 PM EDT. It was in force for 16 hr.

The area

The counties it named.

The facts

Issued: Jul 31, 2018, 3:46 AM EDT (07:46 UTC)
In effect from: Jul 31, 2018, 12:00 PM EDT
Expired: Aug 1, 2018, 3:44 AM EDT
In force: 16 hr
Issued by: NWS Blacksburg, VA
Flood severity: None

All 22 counties

Alleghany County, NC, Ashe County, NC, Rockingham County, NC, Stokes County, NC, Surry County, NC, Watauga County, NC, Wilkes County, NC, Yadkin County, NC, Amherst County, VA, Bedford County, VA, Campbell County, VA, Carroll County, VA, City of Danville, VA, City of Galax, VA, City of Lynchburg, VA, City of Martinsville, VA, Floyd County, VA, Franklin County, VA, Grayson County, VA, Henry County, VA, Patrick County, VA, Pittsylvania County, VA

The radar

The Roanoke radar (KFCX), 34 km from the middle of the area, began a volume at 07:45 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

Greensboro/Hi Pt, NC (KGSO), launched 00:00Z, 7.8 hours before the alert went out and 78 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: 1556 J/kg
Mixed-layer CIN: -6 J/kg
Mixed-layer LCL: 825 m above ground
0-6 km bulk shear: 28 kt
0-1 km storm-relative helicity: -30 m²/s²
0-3 km storm-relative helicity: 18 m²/s²
Significant tornado parameter: -0.1
Supercell composite: -1.2

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 Jul 31, 1:42 AM EDT, 2 hours 4 minutes earlier.

Area forecast discussion, Jul 31, 1:42 AM EDT, 2 hours 4 minutes before

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Hazardous weather outlook, Jul 30, 4:10 PM EDT, 11 hours 36 minutes before

Hazardous Weather Outlook
National Weather Service Blacksburg VA
410 PM EDT Mon Jul 30 2018

NCZ002>006-019-020-VAZ016-017-032>035-043>047-058-059-312015-
Alleghany NC-Surry-Stokes-Rockingham-Caswell-Wilkes-Yadkin-Carroll-
Floyd-Patrick-Franklin-Bedford-Amherst-Henry-Pittsylvania-Campbell-
Appomattox-Buckingham-Halifax-Charlotte-
410 PM EDT Mon Jul 30 2018

This Hazardous Weather Outlook is for north central North Carolina,
northwest North Carolina, central Virginia, south central Virginia,
southwest Virginia and west central Virginia.

.DAY ONE...Tonight.

Thunderstorms this evening will produce heavy rain at times, which
could lead to localized flooding. Also, some of the storms could
become strong to severe, with damaging winds the main threat.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday.

A wet weather pattern is expected this week with the potential for
periods of heavy rainfall and thunderstorms. This may lead to
localized flooding in some areas.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

NCZ001-018-VAZ007-009>015-018>020-022>024-WVZ042>044-507-508-312015-
Ashe-Watauga-Tazewell-Smyth-Bland-Giles-Wythe-Pulaski-Montgomery-
Grayson-Craig-Alleghany VA-Bath-Roanoke-Botetourt-Rockbridge-Mercer-
Summers-Monroe-Eastern Greenbrier-Western Greenbrier-
410 PM EDT Mon Jul 30 2018

This Hazardous Weather Outlook is for northwest North Carolina,
southwest Virginia, west central Virginia and southeast West
Virginia.

.DAY ONE...Today and tonight.

A few thunderstorms during early evening may become strong to
severe, capable of producing locally damaging winds, heavy rain and
frequent lightning.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday.

A wet weather pattern continues for the rest of the week. Heavy
rainfall from thunderstorms may lead to localized flooding.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

In the hours before

Special weather statement, Jul 30, 10:18 PM EDT, 5 hours 28 minutes before

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Special weather statement, Jul 30, 11:01 PM EDT, 4 hours 45 minutes before

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Local storm report, Jul 30, 11:07 PM EDT, 4 hours 39 minutes before

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Special weather statement, Jul 30, 11:19 PM EDT, 4 hours 27 minutes before

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Special weather statement, Jul 30, 11:23 PM EDT, 4 hours 23 minutes before

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Local storm report, Jul 31, 1:52 AM EDT, 1 hour 54 minutes before

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The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 30, 8:15 PM EDT	Special Weather Statement	RNK	Floyd	45 min
Jul 30, 8:16 PM EDT	Areal Flood Advisory	RNK	Bedford, Campbell	2 hr
Jul 30, 8:29 PM EDT	Areal Flood Advisory	RNK	Grayson, Wythe	2 hr
Jul 30, 8:32 PM EDT	Areal Flood Advisory	RNK	Floyd, Franklin, Patrick	2 hr
Jul 30, 8:34 PM EDT	Special Weather Statement	RNK	Franklin	41 min
Jul 30, 8:52 PM EDT	Flash Flood Warning	RNK	Franklin	6 hr
Jul 30, 9:03 PM EDT	Special Weather Statement	RNK	Henry, Patrick	42 min
Jul 30, 9:07 PM EDT	Special Weather Statement	RNK	Franklin	38 min
Jul 30, 9:37 PM EDT	Areal Flood Advisory	RNK	Carroll, Floyd, Patrick	68 min
Jul 30, 9:39 PM EDT	Severe Thunderstorm Warning	RNK	Henry, Patrick	36 min
Jul 30, 9:52 PM EDT	Special Weather Statement	RNK	Charlotte	53 min
Jul 30, 9:57 PM EDT	Areal Flood Advisory	RNK	Henry, Patrick	45 min
Jul 30, 10:38 PM EDT	Flash Flood Warning	RNK	Carroll, Henry, Patrick	6 hr
Jul 30, 11:23 PM EDT	Special Weather Statement	RNK	Pittsylvania	67 min
Jul 30, 11:51 PM EDT	Areal Flood Warning	RNK	Franklin, Henry, Pittsylvania, City of Martinsville	4 hr
Jul 31, 4:24 PM EDT	Special Weather Statement	RNK	Smyth, Tazewell	66 min
Jul 31, 5:29 PM EDT	Special Weather Statement	RNK	Bland, Smyth	61 min
Jul 31, 6:23 PM EDT	Areal Flood Advisory	RNK	Bland, Giles, Wythe	112 min
Jul 31, 6:29 PM EDT	Special Weather Statement	RNK	Giles, Wythe	61 min
Jul 30, 9:05 PM EDT	Areal Flood Advisory	RNK	Alleghany, Wilkes	96 min
Jul 30, 9:48 PM EDT	Special Weather Statement	RNK	Surry, Wilkes	57 min
Jul 30, 10:18 PM EDT	Special Weather Statement	RNK	Stokes	57 min
Jul 30, 11:01 PM EDT	Special Weather Statement	RNK	Wilkes	59 min
Jul 30, 11:19 PM EDT	Special Weather Statement	RNK	Stokes	41 min
Jul 31, 1:41 AM EDT	Areal Flood Advisory	RNK	Stokes, Surry, Wilkes, Yadkin	2 hr
Jul 31, 1:29 PM EDT	Areal Flood Advisory	RNK	Surry, Wilkes, Yadkin	61 min
Jul 31, 2:23 PM EDT	Flash Flood Warning	RNK	Surry, Wilkes, Yadkin	6 hr
Jul 31, 2:27 PM EDT	Special Weather Statement	RNK	Yadkin	33 min
Jul 31, 2:30 PM EDT	Severe Thunderstorm Warning	RNK	Surry, Wilkes, Yadkin	60 min
Jul 31, 2:47 PM EDT	Special Weather Statement	RNK	Wilkes	28 min
Jul 31, 2:58 PM EDT	Areal Flood Advisory	RNK	Stokes, Surry, Yadkin	6 hr
Jul 31, 3:28 PM EDT	Special Weather Statement	RNK	Yadkin	62 min
Jul 31, 3:59 PM EDT	Severe Thunderstorm Warning	RNK	Yadkin	61 min
Jul 31, 4:03 PM EDT	Flash Flood Warning	RNK	Yadkin	6 hr
Jul 31, 5:25 PM EDT	Special Weather Statement	RNK	Rockingham, Stokes	65 min
Jul 31, 5:33 PM EDT	Severe Thunderstorm Warning	RNK	Rockingham, Stokes	29 min
Jul 31, 4:53 PM EDT	Special Weather Statement	RNK	Greenbrier	37 min

Nearby

Flash Flood Watches in Virginia, 2018 Flash Flood Watches in North Carolina, 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.