Alert archive / Virginia / Mesoscale Discussions in 2011
Mesoscale Discussion 1490
The Storm Prediction Center issued this mesoscale discussion at Jul 3, 2011, 8:41 PM EDT for 4 states. It was in force for 64 min.
The area
The outline as issued.
The facts
- Issued
- Jul 3, 2011, 8:41 PM EDT (00:41 UTC)
- Expired
- Jul 3, 2011, 9:45 PM EDT
- In force
- 64 min
- Issued by
- the Storm Prediction Center
All 32 counties
Kent County, DE, Sussex County, DE, Calvert County, MD, Caroline County, MD, Charles County, MD, Dorchester County, MD, Saint Mary's County, MD, Somerset County, MD, Wicomico County, MD, Worcester County, MD, Atlantic County, NJ, Cape May County, NJ, Cumberland County, NJ, Accomack County, VA, Caroline County, VA, Charles City County, VA, City of Fredericksburg, VA, City of Richmond, VA, Essex County, VA, Hanover County, VA, Henrico County, VA, King and Queen County, VA, King George County, VA, King William County, VA, Lancaster County, VA, Middlesex County, VA, New Kent County, VA, Northumberland County, VA, Richmond County, VA, Spotsylvania County, VA, Stafford County, VA, Westmoreland County, VA
The radar
The Dover AFB radar (KDOX), 92 km from the middle of the area, began a volume at 00:42 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.
The nearest sounding before it
Wallops Is Stn, VA (KWAL), launched 00:00Z, 0.7 hours before the alert went out and 90 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
- 462 J/kg
- Mixed-layer CIN
- -121 J/kg
- Mixed-layer LCL
- 1523 m above ground
- 0-6 km bulk shear
- 18 kt
- 0-1 km storm-relative helicity
- 42 m²/s²
- 0-3 km storm-relative helicity
- 67 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
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</html>SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 4, 1:54 PM EDT | Mesoscale Discussion | SPC | Allegany, Garrett | 96 min |
| Jul 4, 2:34 PM EDT | Severe Thunderstorm Watch | SPC | Calvert, Charles, Dorchester, Saint Mary's, Somerset, Wicomico and 1 more | 6 hr |
| Jul 4, 6:44 PM EDT | Mesoscale Discussion | SPC | Saint Mary's | 61 min |
| Jul 4, 12:10 PM EDT | Mesoscale Discussion | SPC | Albemarle, Alleghany, Amelia, Amherst, Appomattox, Augusta and 82 more | 95 min |
| Jul 4, 12:50 PM EDT | Severe Thunderstorm Watch | SPC | Amherst, Appomattox, Bedford, Bland, Botetourt, Buckingham and 35 more | 7 hr |
Nearby
Mesoscale Discussions in Virginia, 2011Mesoscale Discussions in Maryland, 2011Mesoscale Discussions in New Jersey, 2011Every mesoscale discussion 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.