Alert archive / Virginia / Tornado Watches in 2014

Tornado Watch 121

April 30, 201424 counties in North Carolina; 47 counties in Virginia

The Storm Prediction Center issued this tornado watch at Apr 30, 2014, 1:15 PM EDT for 24 counties in North Carolina; 47 counties in Virginia. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued: Apr 30, 2014, 1:15 PM EDT (17:15 UTC)
Expired: Apr 30, 2014, 6:27 PM EDT
In force: 5 hr
Issued by: the Storm Prediction Center
Largest hail expected: 1 in
Strongest gust expected: 60 kt

All 71 counties

Beaufort County, NC, Bertie County, NC, Camden County, NC, Chowan County, NC, Currituck County, NC, Dare County, NC, Edgecombe County, NC, Franklin County, NC, Gates County, NC, Granville County, NC, Halifax County, NC, Hertford County, NC, Hyde County, NC, Martin County, NC, Nash County, NC, Northampton County, NC, Pasquotank County, NC, Perquimans County, NC, Pitt County, NC, Tyrrell County, NC, Vance County, NC, Warren County, NC, Washington County, NC, Wilson County, NC, Amelia County, VA, Brunswick County, VA, Caroline County, VA, Charles City County, VA, Chesterfield County, VA, City of Chesapeake, VA, City of Colonial Heights, VA, City of Emporia, VA, City of Franklin, VA, City of Hampton, VA, City of Hopewell, VA, City of Newport News, VA, City of Norfolk, VA, City of Petersburg, VA, City of Poquoson, VA, City of Portsmouth, VA, City of Richmond, VA, City of Suffolk, VA, City of Virginia Beach, VA, City of Williamsburg, VA, Dinwiddie County, VA, Essex County, VA, Gloucester County, VA, Goochland County, VA, Greensville County, VA, Hanover County, VA, Henrico County, VA, Isle of Wight County, VA, James City County, VA, King and Queen County, VA, King William County, VA, Lancaster County, VA, Lunenburg County, VA, Mathews County, VA, Mecklenburg County, VA, Middlesex County, VA, New Kent County, VA, Northumberland County, VA, Nottoway County, VA, Powhatan County, VA, Prince George County, VA, Richmond County, VA, Southampton County, VA, Surry County, VA, Sussex County, VA, Westmoreland County, VA, York County, VA

The radar

The Norfolk radar (KAKQ), 40 km from the middle of the area, began a volume at 17:18 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.

What SPC expected

The probabilities SPC published with the watch, for the watch area over its life.

Two or more tornadoes: 40%
One or more EF2 to EF5 tornadoes: 20%
Ten or more severe wind reports: 30%
One or more gusts of 65 knots or more: 10%
Ten or more severe hail reports: 20%
One or more hailstones of 2 inches or more: 5%
Six or more combined severe hail and wind reports: 60%

Warnings issued inside it

4 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

Issued	Product	Office	Counties	Lasted
Apr 30, 1:29 PM EDT	Severe Thunderstorm Warning	AKQ	Essex, King and Queen, King William, Lancaster, Middlesex, Richmond	46 min
Apr 30, 3:24 PM EDT	Flash Flood Warning	RAH	Halifax	2 hr
Apr 30, 3:33 PM EDT	Severe Thunderstorm Warning	AKQ	James City, City of Newport News	27 min
Apr 30, 3:45 PM EDT	Severe Thunderstorm Warning	MHX	Beaufort, Carteret, Craven, Greene, Jones, Lenoir and 3 more	45 min

Discussions around it

SPC mesoscale discussions over the same counties from four hours before the watch to its end.

The nearest sounding before it

Roanoke, VA (KRNK), launched 12:00Z, 5.3 hours before the alert went out and 182 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: 452 m above ground
0-6 km bulk shear: 53 kt
0-1 km storm-relative helicity: 292 m²/s²
0-3 km storm-relative helicity: 371 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.2

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

313 
WWUS20 KWNS 301714
SEL1  
SPC WW 301714
NCZ000-VAZ000-CWZ000-302300-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 121
NWS STORM PREDICTION CENTER NORMAN OK
115 PM EDT WED APR 30 2014

THE NWS STORM PREDICTION CENTER HAS ISSUED A

* TORNADO WATCH FOR PORTIONS OF 
  NORTHEAST NORTH CAROLINA
  SOUTHEAST VIRGINIA
  COASTAL WATERS

* EFFECTIVE THIS WEDNESDAY AFTERNOON AND EVENING FROM 115 PM
  UNTIL 700 PM EDT.

* PRIMARY THREATS INCLUDE...
  A COUPLE TORNADOES POSSIBLE
  ISOLATED DAMAGING WIND GUSTS TO 70 MPH POSSIBLE
  ISOLATED LARGE HAIL EVENTS TO 1 INCH IN DIAMETER POSSIBLE

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 55 STATUTE
MILES EAST AND WEST OF A LINE FROM 30 MILES NORTH NORTHEAST OF
RICHMOND VIRGINIA TO 25 MILES EAST SOUTHEAST OF ROCKY MOUNT NORTH
CAROLINA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE
ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU1).

PRECAUTIONARY/PREPAREDNESS ACTIONS...

REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR
TORNADOES AND SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH
AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR
THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS
AND POSSIBLE WARNINGS.

&&

DISCUSSION...SCATTERED THUNDERSTORMS DEVELOPING IN A MOIST
ENVIRONMENT WILL RESULT IN THE POTENTIAL FOR SUPERCELLS CAPABLE OF
PRODUCING A COUPLE TORNADOES THIS AFTERNOON.  THE TORNADO THREAT
WILL BE SUPPORTED BY SOMEWHAT ENHANCED LOW-LEVEL SHEAR ALONG AND E
OF A WARM FRONT ACROSS THE PIEDMONT...WHERE SURFACE DEWPOINTS OF
68-70 F AND TEMPERATURES IN THE UPPER 70S ARE CONTRIBUTING TO
MODERATE SURFACE-BASED INSTABILITY.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 1 INCH. EXTREME TURBULENCE AND SURFACE WIND
GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 450.
MEAN STORM MOTION VECTOR 22025.


...THOMPSON

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Apr 30, 5:22 AM EDT	Mesoscale Discussion	SPC	Cumberland, Durham, Edgecombe, Franklin, Granville, Greene and 11 more	53 min
Apr 30, 12:33 PM EDT	Mesoscale Discussion	SPC	Beaufort, Bertie, Bladen, Camden, Chowan, Craven and 29 more	87 min
Apr 30, 3:47 PM EDT	Mesoscale Discussion	SPC	Beaufort, Bertie, Camden, Carteret, Chowan, Craven and 25 more	88 min
Apr 30, 5:01 PM EDT	Mesoscale Discussion	SPC	Buchanan, Russell, Tazewell, Washington, City of Bristol	89 min

Nearby

Tornado Watches in Virginia, 2014 Tornado Watches in North Carolina, 2014 Every tornado watch in 2014

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.