Alert archive / Virginia / Severe Thunderstorm Watches in 2011
Severe Thunderstorm Watch 545
The Storm Prediction Center issued this severe thunderstorm watch at Jun 24, 2011, 2:25 PM EDT for 6 counties in Maryland; 8 counties in North Carolina; 16 counties in Virginia. It was in force for 4 hr.
The area
The outline as issued.
The facts
- Issued
- Jun 24, 2011, 2:25 PM EDT (18:25 UTC)
- Expired
- Jun 24, 2011, 6:15 PM EDT
- In force
- 4 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1.5 in
- Strongest gust expected
- 60 kt
All 30 counties
Calvert County, MD, Dorchester County, MD, Saint Mary's County, MD, Somerset County, MD, Wicomico County, MD, Worcester County, MD, Bertie County, NC, Camden County, NC, Chowan County, NC, Currituck County, NC, Gates County, NC, Hertford County, NC, Pasquotank County, NC, Perquimans County, NC, Accomack County, VA, City of Chesapeake, VA, City of Hampton, VA, City of Newport News, VA, City of Norfolk, VA, City of Portsmouth, VA, City of Suffolk, VA, City of Virginia Beach, VA, Gloucester County, VA, Isle of Wight County, VA, Lancaster County, VA, Mathews County, VA, Middlesex County, VA, Northampton County, VA, Northumberland County, VA, York County, VA
The radar
The Norfolk radar (KAKQ), 114 km from the middle of the area, began a volume at 18:25 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
- 20%
- One or more EF2 to EF5 tornadoes
- 5%
- Ten or more severe wind reports
- 30%
- One or more gusts of 65 knots or more
- 30%
- Ten or more severe hail reports
- 30%
- One or more hailstones of 2 inches or more
- 20%
- Six or more combined severe hail and wind reports
- 70%
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 |
|---|---|---|---|---|
| Jun 24, 3:45 PM EDT | Severe Thunderstorm Warning | AKQ | York, City of Newport News, City of Poquoson | 45 min |
| Jun 24, 3:55 PM EDT | Severe Thunderstorm Warning | AKQ | York, City of Hampton, City of Newport News, City of Poquoson | 50 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
Phillips Aaf/Abe, MD (KAPG), launched 12:00Z, 6.4 hours before the alert went out and 210 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
- 822 J/kg
- Mixed-layer CIN
- -54 J/kg
- Mixed-layer LCL
- 899 m above ground
- 0-6 km bulk shear
- 41 kt
- 0-1 km storm-relative helicity
- 32 m²/s²
- 0-3 km storm-relative helicity
- 78 m²/s²
- Significant tornado parameter
- 0.3
- Supercell composite
- 3.5
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 24, 12:46 PM EDT | Severe Thunderstorm Watch | SPC | Caroline, Cecil, Kent, Queen Anne's, Talbot | 7 hr |
| Jun 24, 1:05 PM EDT | Mesoscale Discussion | SPC | Anne Arundel, Calvert, Charles, Dorchester, Frederick, Howard and 6 more | 2 hr |
| Jun 24, 4:13 PM EDT | Mesoscale Discussion | SPC | Caroline, Cecil, Dorchester, Kent, Queen Anne's, Saint Mary's and 4 more | 92 min |
| Jun 24, 2:49 PM EDT | Severe Thunderstorm Watch | SPC | Cherokee, Clay | 7 hr |
| Jun 24, 4:42 PM EDT | Mesoscale Discussion | SPC | Cherokee, Clay, Graham, Jackson, Macon | 93 min |
Nearby
Severe Thunderstorm Watches in Virginia, 2011Severe Thunderstorm Watches in North Carolina, 2011Severe Thunderstorm Watches in Maryland, 2011Every severe thunderstorm 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.