Alert archive / Virginia / Flash Flood Warnings in 2020

Flash Flood Warning 36, NWS Wakefield, VA

August 9, 2020Hanover County, Henrico County, Virginia

NWS Wakefield, VA issued this flash flood warning at Aug 9, 2020, 6:31 PM EDT for Hanover County, Henrico County, Virginia. It was in force for 93 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Aug 9, 2020, 6:31 PM EDT (22:31 UTC)
Expired
Aug 9, 2020, 8:04 PM EDT
In force
93 min
Issued by
NWS Wakefield, VA
Area
Storm-based polygon
Flood severity
None

Counties Hanover County, VA, Henrico County, VA

The radar

The Norfolk radar (KAKQ), 77 km from the middle of the area, began a volume at 22:31 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

Washington/Dulle, VA (KIAD), launched 12:00Z, 10.5 hours before the alert went out and 149 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, Washington/Dulle, VA at 12:00Z on 2020-08-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 712 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, Washington/Dulle, VA at 12:00Z on 2020-08-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 30 square meters per square second.1939Sfc1 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
712 J/kg
Mixed-layer CIN
-34 J/kg
Mixed-layer LCL
789 m above ground
0-6 km bulk shear
10 kt
0-1 km storm-relative helicity
30 m²/s²
0-3 km storm-relative helicity
59 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 9, 2:24 PM EDTSpecial Weather StatementAKQNottoway, Prince Edward51 min
Aug 9, 3:53 PM EDTSpecial Weather StatementAKQNottoway52 min
Aug 9, 6:03 PM EDTSpecial Weather StatementAKQHanover57 min
Aug 9, 6:09 PM EDTAreal Flood AdvisoryAKQHanover, Henrico22 min

Nearby

Flash Flood Warnings in Virginia, 2020Every flash flood warning in 2020

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.