Alert archive / Virginia / Tornado Watches in 2008
Tornado Watch 210
The Storm Prediction Center issued this tornado watch at Apr 20, 2008, 8:01 PM EDT for 24 counties in North Carolina; 32 counties in Virginia. It was in force for 5 hr.
The area
The outline as issued.
The facts
- Issued
- Apr 20, 2008, 8:01 PM EDT (00:01 UTC)
- Expired
- Apr 21, 2008, 1:00 AM EDT
- In force
- 5 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 0.5 in
- Strongest gust expected
- 50 kt
All 56 counties
Beaufort County, NC, Bertie County, NC, Camden County, NC, Carteret County, NC, Chowan County, NC, Craven County, NC, Currituck County, NC, Dare County, NC, Duplin County, NC, Gates County, NC, Greene County, NC, Hertford County, NC, Hyde County, NC, Jones County, NC, Lenoir County, NC, Martin County, NC, Northampton County, NC, Onslow County, NC, Pamlico County, NC, Pasquotank County, NC, Perquimans County, NC, Pitt County, NC, Tyrrell County, NC, Washington County, NC, Accomack County, VA, Caroline County, VA, Charles City County, VA, City of Chesapeake, VA, City of Colonial Heights, VA, City of Franklin, VA, City of Hampton, VA, City of Newport News, VA, City of Norfolk, VA, City of Poquoson, VA, City of Portsmouth, VA, City of Suffolk, VA, City of Virginia Beach, VA, City of Williamsburg, VA, Essex County, VA, Gloucester County, VA, Isle of Wight County, VA, James City County, VA, King and Queen County, VA, King William County, VA, Lancaster County, VA, Mathews County, VA, Middlesex County, VA, New Kent County, VA, Northampton County, VA, Northumberland 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), 45 km from the middle of the area, began a volume at 00:03 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
- 30%
- One or more EF2 to EF5 tornadoes
- 10%
- Ten or more severe wind reports
- 20%
- One or more gusts of 65 knots or more
- 5%
- 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
- 50%
Warnings issued inside it
2 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 20, 8:12 PM EDT | Severe Thunderstorm Warning | AKQ | Bertie, Gates, Hertford, Northampton | 33 min |
| Apr 20, 9:43 PM EDT | Severe Thunderstorm Warning | MHX | Craven, Pitt | 35 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
Wallops Is Stn, VA (KWAL), launched 00:00Z, 0.0 hours before the alert went out and 183 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.
- Mixed-layer CAPE
- 871 J/kg
- Mixed-layer CIN
- -10 J/kg
- Mixed-layer LCL
- 721 m above ground
- 0-6 km bulk shear
- 18 kt
- 0-1 km storm-relative helicity
- 96 m²/s²
- 0-3 km storm-relative helicity
- 101 m²/s²
- Significant tornado parameter
- 0.2
- Supercell composite
- 1.8
The text
As transmitted, in the capitals the NWS used until 2016.
000
WWUS20 KWNS 210002
SEL0
SPC WW 210002
NCZ000-VAZ000-CWZ000-210500-
URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 210
NWS STORM PREDICTION CENTER NORMAN OK
800 PM EDT SUN APR 20 2008
THE NWS STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF
EASTERN NORTH CAROLINA
SOUTHEASTERN VIRGINIA
COASTAL WATERS
EFFECTIVE THIS SUNDAY NIGHT AND MONDAY MORNING FROM 800 PM UNTIL
100 AM EDT.
TORNADOES...HAIL TO 0.5 INCH IN DIAMETER...THUNDERSTORM WIND
GUSTS TO 60 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE
AREAS.
THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 50 STATUTE
MILES EAST AND WEST OF A LINE FROM 55 MILES NORTHEAST OF RICHMOND
VIRGINIA TO 50 MILES SOUTHEAST OF NEW BERN NORTH CAROLINA. FOR A
COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE
UPDATE (WOUS64 KWNS WOU0).
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.
OTHER WATCH INFORMATION...CONTINUE...WW 209...
DISCUSSION...SHORT BANDS/CLUSTERS OF STORMS WILL CONTINUE ACROSS WW
AREA THROUGH LATE EVENING AS NW NC UPR VORT CONTINUES ESE. NARROW
CURRENT OF MODERATELY MOIST SSELY LOW LEVEL FLOW WILL CONTINUE TO
IMPINGE ON RESIDUAL N/S-ORIENTED OUTFLOW BOUNDARY SEGMENTS FROM
EARLIER STORMS. THIS COULD SUPPORT A CONTINUED THREAT FOR LOW-LEVEL
STORM ROTATION AS TEMP/DEW POINT SPREADS LESSEN...LARGE SCALE ASCENT
STRENGTHENS ...AND STORMS MOVE N ALONG THE BOUNDARIES.
AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 0.5 INCH. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 50 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
400. MEAN STORM MOTION VECTOR 18030.
...CORFIDISPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 20, 11:08 PM EDT | Mesoscale Discussion | SPC | Beaufort, Camden, Carteret, Chowan, Currituck, Dare and 7 more | 67 min |
| Apr 21, 11:14 AM EDT | Mesoscale Discussion | SPC | Beaufort, Bertie, Chowan, Craven, Duplin, Durham and 23 more | 2 hr |
Nearby
Tornado Watches in Virginia, 2008Tornado Watches in North Carolina, 2008Every tornado watch in 2008
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.