Alert archive / Virginia / Flash Flood Warnings in 2018

Flash Flood Warning 21, NWS Wakefield, VA

September 11, 2018Hanover County, Henrico County, City of Richmond, Virginia

NWS Wakefield, VA issued this flash flood warning at Sep 11, 2018, 8:05 PM EDT for Hanover County, Henrico County, City of Richmond, Virginia. It was in force for 3 hr. 2 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: Sep 11, 2018, 8:05 PM EDT (00:05 UTC)
Expired: Sep 11, 2018, 11:00 PM EDT
In force: 3 hr
Issued by: NWS Wakefield, VA
Area: Storm-based polygon
Flood severity: None

Counties City of Richmond, VA, Hanover County, VA, Henrico County, VA

The radar

The Norfolk radar (KAKQ), 79 km from the middle of the area, began a volume at 00:06 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.

What was reported inside it

Time	Report	Where	Remark
Sep 11, 8:35 PM EDT	FLASH FLOOD	3 S Studley, VA	ROADS FLOODED THROUGHOUT THE MECHANICSVILLE AREA.
Sep 11, 8:54 PM EDT	FLASH FLOOD	1 Wnw Solomons Store, VA	ROADS FLOODED SOUTH OF GLEN ALLEN.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 00:00Z, 0.1 hours before the alert went out and 144 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: 550 m above ground
0-6 km bulk shear: 12 kt
0-1 km storm-relative helicity: 78 m²/s²
0-3 km storm-relative helicity: 113 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

935 
WGUS51 KAKQ 120005
FFWAKQ
VAC085-087-760-120300-
/O.NEW.KAKQ.FF.W.0021.180912T0005Z-180912T0300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Wakefield VA
805 PM EDT TUE SEP 11 2018

The National Weather Service in Wakefield has issued a

* Flash Flood Warning for...
  The City of Richmond in central Virginia...
  Northwestern Henrico County in central Virginia...
  Southeastern Hanover County in central Virginia...

* Until 1100 PM EDT.

* At 804 PM EDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Locally up to 3 inches of rain 
  has fallen, and an additional inch or two is possible through 9 
  pm.  Flash flooding is expected to begin shortly.

* Some locations that will experience flooding include...
  Richmond, Downtown Richmond, Virginia Union University,
  Mechanicsville, Highland Springs, Virginia Commonwealth University,
  Tuckahoe, Studley, East Highland Park, Lakeside, Laurel, Glen
  Allen, Westwood, Solomons Store, Chamberlayne, Atlee, Ashcake,
  Greendale, Dumbarton and Montrose.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood 
deaths occur in vehicles.
 
Please report flooding by calling 757-899-2415, posting to the NWS
Wakefield Facebook page, or using Twitter @NWSWAKEFIELDVA.

LAT...LON 3769 7743 3772 7730 3771 7729 3772 7727
      3771 7725 3773 7725 3772 7723 3769 7724
      3769 7721 3768 7721 3769 7720 3768 7720
      3760 7714 3759 7716 3760 7717 3759 7718
      3751 7747 3758 7755

$$

MRD

2 follow-up statements

657 
WGUS71 KAKQ 120141
FFSAKQ

Flash Flood Statement
National Weather Service Wakefield VA
941 PM EDT TUE SEP 11 2018

VAC085-087-760-120300-
/O.CON.KAKQ.FF.W.0021.000000T0000Z-180912T0300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
City of Richmond VA-Henrico VA-Hanover VA-
941 PM EDT TUE SEP 11 2018

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1100 PM EDT FOR
NORTHWESTERN HENRICO AND SOUTHEASTERN HANOVER COUNTIES AND THE CITY
OF RICHMOND...

At 916 PM EDT, local law enforcement reported flash flooding due to 
thunderstorms near Mechanicsville and Solomans Store. Up to three 
inches of rain have already fallen. The rainfall has diminished, but 
flash flooding is expected to continue.

Some locations that will experience flooding include...
Richmond, Downtown Richmond, Virginia Union University,
Mechanicsville, Highland Springs, Virginia Commonwealth University,
Tuckahoe, Studley, East Highland Park, Lakeside, Laurel, Glen Allen,
Westwood, Solomons Store, Chamberlayne, Atlee, Ashcake, Greendale,
Dumbarton and Montrose.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.

&&

LAT...LON 3769 7743 3772 7730 3771 7729 3772 7727
      3771 7725 3773 7725 3772 7723 3769 7724
      3769 7721 3768 7721 3769 7720 3768 7720
      3760 7714 3759 7716 3760 7717 3759 7718
      3751 7747 3758 7755

$$

MRD

875 
WGUS71 KAKQ 120253
FFSAKQ

Flash Flood Statement
National Weather Service Wakefield VA
1053 PM EDT TUE SEP 11 2018

VAC085-087-760-120302-
/O.EXP.KAKQ.FF.W.0021.000000T0000Z-180912T0300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
City of Richmond VA-Henrico VA-Hanover VA-
1053 PM EDT TUE SEP 11 2018

...THE FLASH FLOOD WARNING FOR NORTHWESTERN HENRICO AND SOUTHEASTERN
HANOVER COUNTIES AND THE CITY OF RICHMOND WILL EXPIRE AT 1100 PM
EDT...

The heavy rain has ended. Flooding is no longer expected to pose a
threat. Please continue to heed any remaining road closures.

LAT...LON 3769 7743 3772 7730 3771 7729 3772 7727
      3771 7725 3773 7725 3772 7723 3769 7724
      3769 7721 3768 7721 3769 7720 3768 7720
      3760 7714 3759 7716 3760 7717 3759 7718
      3751 7747 3758 7755

$$

MRD

The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 11, 8:18 PM EDT	Areal Flood Advisory	AKQ	Amelia, Chesterfield, Powhatan	3 hr
Sep 11, 9:36 PM EDT	Special Weather Statement	AKQ	Fluvanna	39 min
Sep 11, 10:20 PM EDT	Special Weather Statement	AKQ	Louisa	25 min
Sep 12, 5:11 AM EDT	Tropical Storm Warning	AKQ	City of Chesapeake, City of Hampton, City of Virginia Beach	54 hr
Sep 12, 5:58 AM EDT	Coastal Flood Advisory	AKQ	Gloucester, Mathews, Middlesex	10 hr
Sep 12, 4:18 PM EDT	Coastal Flood Watch	AKQ	Accomack, Gloucester, James City, Lancaster, Mathews, Middlesex and 11 more	25 hr
Sep 12, 7:05 PM EDT	High Surf Advisory	AKQ	Accomack, Northampton	44 hr

Nearby

Flash Flood Warnings in Virginia, 2018 Every flash flood warning 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.