Alert archive / Virginia / Flash Flood Watches in 2018

Flash Flood Watch 9, NWS Wakefield, VA

August 3, 201810 counties in Virginia

NWS Wakefield, VA issued this flash flood watch at Aug 3, 2018, 3:15 AM EDT for 10 counties in Virginia. It was in force for 17 hr.

The area

The counties it named.

The facts

Issued
Aug 3, 2018, 3:15 AM EDT (07:15 UTC)
Expired
Aug 3, 2018, 7:58 PM EDT
In force
17 hr
Issued by
NWS Wakefield, VA
Flood severity
None

Counties Amelia County, VA, Cumberland County, VA, Fluvanna County, VA, Goochland County, VA, Louisa County, VA, Lunenburg County, VA, Mecklenburg County, VA, Nottoway County, VA, Powhatan County, VA, Prince Edward County, VA

The radar

The Norfolk radar (KAKQ), 110 km from the middle of the area, began a volume at 07:18 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, 7.3 hours before the alert went out and 122 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-pSkew-T log-p diagram, Roanoke, VA at 00:00Z on 2018-08-03Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 426 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Roanoke, VA at 00:00Z on 2018-08-03The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 114 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
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
426 J/kg
Mixed-layer CIN
-4 J/kg
Mixed-layer LCL
722 m above ground
0-6 km bulk shear
38 kt
0-1 km storm-relative helicity
114 m²/s²
0-3 km storm-relative helicity
186 m²/s²
Significant tornado parameter
0.2
Supercell composite
6.1

Open this sounding in Storm Lab

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 3, 3:26 AM EDTSpecial Weather StatementAKQBrunswick, Lunenburg, Mecklenburg49 min
Aug 3, 6:55 AM EDTSpecial Weather StatementAKQSouthampton, City of Franklin, City of Suffolk50 min
Aug 3, 7:41 AM EDTSpecial Weather StatementAKQIsle of Wight, Southampton, Surry, Sussex, City of Franklin, City of Newport News and 1 more49 min
Aug 3, 8:36 AM EDTSpecial Weather StatementAKQGloucester, Lancaster, Mathews, Middlesex, York, City of Williamsburg39 min
Aug 3, 9:58 AM EDTSpecial Weather StatementAKQAccomack47 min
Aug 3, 10:01 AM EDTSpecial Weather StatementAKQSomerset44 min
Aug 3, 10:32 AM EDTAreal Flood AdvisoryAKQDorchester, Somerset, Wicomico, Worcester111 min
Aug 3, 11:13 AM EDTSpecial Weather StatementAKQDorchester47 min
Aug 3, 3:05 PM EDTSpecial Weather StatementAKQWorcester25 min
Aug 3, 5:14 AM EDTSpecial Weather StatementAKQBertie, Chowan, Perquimans46 min
Aug 3, 6:20 AM EDTSpecial Weather StatementAKQBertie, Chowan, Gates, Hertford, Pasquotank, Perquimans40 min

Nearby

Flash Flood Watches in Virginia, 2018Every 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.