Alert archive / Virginia / Tornado Watches in 2011
Tornado Watch 255
The Storm Prediction Center issued this tornado watch at Apr 28, 2011, 2:41 PM EDT for 4 counties in Maryland; 27 counties in North Carolina; 36 counties in Virginia. It was in force for 6 hr.
The area
The outline as issued.
The facts
- Issued
- Apr 28, 2011, 2:41 PM EDT (18:41 UTC)
- Expired
- Apr 28, 2011, 9:00 PM EDT
- In force
- 6 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1 in
- Strongest gust expected
- 60 kt
All 67 counties
Dorchester County, MD, Somerset County, MD, Wicomico County, MD, Worcester County, MD, Beaufort County, NC, Bertie County, NC, Camden County, NC, Carteret County, NC, Chowan County, NC, Craven County, NC, Cumberland 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, Sampson County, NC, Tyrrell County, NC, Washington County, NC, Wayne County, NC, Accomack County, VA, Charles City 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 Suffolk, VA, City of Virginia Beach, VA, City of Williamsburg, VA, Essex County, VA, Gloucester County, VA, Greensville 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, 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), 31 km from the middle of the area, began a volume at 18:42 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
- 30%
- Ten or more severe hail reports
- 40%
- One or more hailstones of 2 inches or more
- 30%
- Six or more combined severe hail and wind reports
- 70%
Warnings issued inside it
27 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 28, 2:50 PM EDT | Tornado Warning | RAH | Sampson | 23 min |
| Apr 28, 3:10 PM EDT | Tornado Warning | MHX | Duplin, Lenoir | 50 min |
| Apr 28, 3:29 PM EDT | Tornado Warning | MHX | Beaufort, Greene, Martin, Pitt | 46 min |
| Apr 28, 3:48 PM EDT | Tornado Warning | MHX | Craven, Duplin, Jones, Lenoir | 42 min |
| Apr 28, 4:14 PM EDT | Tornado Warning | AKQ | Bertie, Chowan, Perquimans | 46 min |
| Apr 28, 4:26 PM EDT | Tornado Warning | MHX | Beaufort, Craven, Pitt | 49 min |
| Apr 28, 4:32 PM EDT | Tornado Warning | MHX | Duplin, Onslow | 26 min |
| Apr 28, 4:44 PM EDT | Tornado Warning | MHX | Martin, Washington | 31 min |
| Apr 28, 4:49 PM EDT | Tornado Warning | MHX | Beaufort, Craven, Pitt | 22 min |
| Apr 28, 4:51 PM EDT | Tornado Warning | AKQ | Camden, Currituck, Pasquotank | 24 min |
| Apr 28, 4:54 PM EDT | Severe Thunderstorm Warning | AKQ | Camden, Chowan, Currituck, Gates, Pasquotank, Perquimans | 66 min |
| Apr 28, 4:58 PM EDT | Tornado Warning | AKQ | Camden, Pasquotank, Perquimans | 17 min |
| Apr 28, 5:01 PM EDT | Tornado Warning | MHX | Beaufort, Hyde, Washington | 44 min |
| Apr 28, 5:11 PM EDT | Tornado Warning | AKQ | Camden, Currituck, Pasquotank | 19 min |
| Apr 28, 5:15 PM EDT | Tornado Warning | MHX | Tyrrell, Washington | 19 min |
| Apr 28, 5:28 PM EDT | Tornado Warning | AKQ | Currituck | 32 min |
| Apr 28, 5:33 PM EDT | Tornado Warning | MHX | Hyde, Tyrrell, Washington | 42 min |
| Apr 28, 5:42 PM EDT | Severe Thunderstorm Warning | MHX | Craven, Jones, Onslow | 33 min |
| Apr 28, 5:46 PM EDT | Severe Thunderstorm Warning | MHX | Craven, Jones, Onslow | 29 min |
| Apr 28, 5:55 PM EDT | Tornado Warning | MHX | Tyrrell, Washington | 35 min |
| Apr 28, 6:13 PM EDT | Tornado Warning | AKQ | Camden, Currituck | 32 min |
| Apr 28, 6:23 PM EDT | Tornado Warning | MHX | Dare, Tyrrell, Washington | 37 min |
| Apr 28, 6:37 PM EDT | Tornado Warning | AKQ | Camden, Currituck, Pasquotank | 23 min |
| Apr 28, 7:01 PM EDT | Tornado Warning | MHX | Dare | 29 min |
| Apr 28, 7:15 PM EDT | Severe Thunderstorm Warning | AKQ | Charles City, Chesterfield, Essex, Hanover, Henrico, King and Queen and 4 more | 45 min |
| Apr 28, 7:20 PM EDT | Severe Thunderstorm Warning | AKQ | Brunswick, Charles City, Chesterfield, Dinwiddie, James City, New Kent and 6 more | 55 min |
| Apr 28, 7:56 PM EDT | Severe Thunderstorm Warning | AKQ | Charles City, Essex, Gloucester, King and Queen, King William, Lancaster and 4 more | 49 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 12:00Z, 6.7 hours before the alert went out and 156 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
- 90 J/kg
- Mixed-layer CIN
- -342 J/kg
- Mixed-layer LCL
- 795 m above ground
- 0-6 km bulk shear
- 37 kt
- 0-1 km storm-relative helicity
- 295 m²/s²
- 0-3 km storm-relative helicity
- 277 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.6
The text
As transmitted, in the capitals the NWS used until 2016.
201
WWUS20 KWNS 281840
SEL5
SPC WW 281840
MDZ000-NCZ000-VAZ000-CWZ000-290100-
URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 255
NWS STORM PREDICTION CENTER NORMAN OK
240 PM EDT THU APR 28 2011
THE NWS STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF
SOUTHEAST MARYLAND
EASTERN NORTH CAROLINA
EASTERN VIRGINIA
COASTAL WATERS
EFFECTIVE THIS THURSDAY AFTERNOON AND EVENING FROM 240 PM UNTIL
900 PM EDT.
TORNADOES...HAIL TO 1 INCH IN DIAMETER...THUNDERSTORM WIND GUSTS
TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.
THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 70 STATUTE
MILES EAST AND WEST OF A LINE FROM 25 MILES WEST NORTHWEST OF
SALISBURY MARYLAND TO 30 MILES EAST SOUTHEAST OF JACKSONVILLE
NORTH CAROLINA. FOR A COMPLETE DEPICTION OF THE WATCH SEE THE
ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU5).
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 251...WW 252...WW
253...WW 254...
DISCUSSION...SCATTERED THUNDERSTORMS PERSIST ACROSS PARTS OF EASTERN
NC AND SOUTHEAST VA WHERE MODERATE INSTABILITY PERSISTS. LOW LEVEL
SHEAR HAS BEEN DIMINISHING WITH TIME...BUT REMAINS SUFFICIENT FOR A
FEW SUPERCELL STORMS CAPABLE OF DAMAGING WINDS AND ISOLATED
TORNADOES.
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 24040.
...HARTSPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 27, 8:15 PM EDT | Severe Thunderstorm Watch | SPC | Caroline, Cecil, Kent, Queen Anne's, Talbot | 8 hr |
| Apr 28, 12:27 AM EDT | Mesoscale Discussion | SPC | Allegany, Frederick, Howard, Montgomery, Washington | 63 min |
| Apr 28, 12:41 AM EDT | Tornado Watch | SPC | Allegany, Anne Arundel, Baltimore, Calvert, Carroll, Charles and 8 more | 7 hr |
| Apr 28, 4:05 AM EDT | Severe Thunderstorm Watch | SPC | Caroline, Cecil, Kent, Queen Anne's, Talbot | 6 hr |
| Apr 28, 7:38 AM EDT | Tornado Watch | SPC | Anne Arundel, Baltimore, Calvert, Carroll, Charles, Dorchester and 10 more | 7 hr |
| Apr 28, 9:45 AM EDT | Severe Thunderstorm Watch | SPC | Caroline, Cecil, Kent, Queen Anne's, Talbot | 6 hr |
| Apr 28, 10:44 AM EDT | Mesoscale Discussion | SPC | Anne Arundel, Baltimore, Calvert, Caroline, Carroll, Cecil and 13 more | 61 min |
| Apr 28, 11:49 AM EDT | Mesoscale Discussion | SPC | Cecil, Kent, Queen Anne's | 56 min |
| Apr 28, 2:00 PM EDT | Mesoscale Discussion | SPC | Anne Arundel, Calvert, Caroline, Charles, Dorchester, Kent and 7 more | 60 min |
| Apr 28, 6:33 PM EDT | Mesoscale Discussion | SPC | Dorchester, Saint Mary's, Somerset, Wicomico, Worcester | 57 min |
| Apr 27, 10:12 PM EDT | Mesoscale Discussion | SPC | Alleghany, Ashe, Forsyth, Rockingham, Stokes, Surry and 3 more | 63 min |
| Apr 28, 12:09 AM EDT | Mesoscale Discussion | SPC | Alexander, Alleghany, Ashe, Avery, Buncombe, Burke and 25 more | 36 min |
| Apr 28, 12:56 AM EDT | Tornado Watch | SPC | Alexander, Avery, Buncombe, Burke, Cabarrus, Caldwell and 21 more | 4 hr |
| Apr 28, 3:30 AM EDT | Mesoscale Discussion | SPC | Alexander, Anson, Burke, Cabarrus, Catawba, Cleveland and 10 more | 90 min |
| Apr 28, 4:30 AM EDT | Tornado Watch | SPC | Alamance, Anson, Bladen, Chatham, Cumberland, Davidson and 27 more | 10 hr |
| Apr 28, 8:05 AM EDT | Mesoscale Discussion | SPC | Anson, Chatham, Cumberland, Durham, Edgecombe, Franklin and 15 more | 85 min |
| Apr 28, 8:48 AM EDT | Tornado Watch | SPC | Beaufort, Bladen, Brunswick, Carteret, Columbus, Craven and 15 more | 7 hr |
| Apr 28, 11:22 AM EDT | Mesoscale Discussion | SPC | Beaufort, Bertie, Bladen, Brunswick, Chowan, Columbus and 29 more | 53 min |
| Apr 28, 3:19 PM EDT | Tornado Watch | SPC | Bladen, Brunswick, Columbus, New Hanover, Pender | 4 hr |
| Apr 27, 9:22 PM EDT | Mesoscale Discussion | SPC | Buchanan, Dickenson, Lee, Russell, Scott, Smyth and 5 more | 53 min |
| Apr 28, 12:34 AM EDT | Mesoscale Discussion | SPC | Buchanan, Dickenson, Lee, Russell, Scott, Tazewell and 3 more | 26 min |
Nearby
Tornado Watches in Virginia, 2011Tornado Watches in North Carolina, 2011Tornado Watches in Maryland, 2011Every tornado watch in 2011
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.