Alert archive / Virginia / Mesoscale Discussions in 2007

Mesoscale Discussion 606

April 27, 20074 states

The Storm Prediction Center issued this mesoscale discussion at Apr 27, 2007, 3:33 PM EDT for 4 states. It was in force for 117 min.

The area

The outline as issued.

The facts

Issued
Apr 27, 2007, 3:33 PM EDT (19:33 UTC)
Expired
Apr 27, 2007, 5:30 PM EDT
In force
117 min
Issued by
the Storm Prediction Center
All 85 counties

Sussex County, DE, Calvert County, MD, Dorchester County, MD, Saint Mary's County, MD, Somerset County, MD, Talbot County, MD, Wicomico County, MD, Worcester County, MD, Beaufort County, NC, Bertie County, NC, Camden County, NC, Chowan County, NC, Craven County, NC, Currituck County, NC, Dare County, NC, Duplin County, NC, Durham County, NC, Edgecombe County, NC, Franklin County, NC, Gates County, NC, Granville County, NC, Greene County, NC, Halifax County, NC, Harnett County, NC, Hertford County, NC, Hyde County, NC, Johnston County, NC, Jones County, NC, Lenoir County, NC, Martin County, NC, Nash County, NC, Northampton County, NC, Pamlico County, NC, Pasquotank County, NC, Perquimans County, NC, Pitt County, NC, Tyrrell County, NC, Vance County, NC, Wake County, NC, Warren County, NC, Washington County, NC, Wayne County, NC, Wilson County, NC, Accomack County, VA, Brunswick 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, Greensville 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, Mathews County, VA, Mecklenburg 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), 53 km from the middle of the area, began a volume at 19:33 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 12:00Z, 7.6 hours before the alert went out and 158 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-pSkew-T log-p diagram, Wallops Is Stn, VA at 12:00Z on 2007-04-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 130 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Wallops Is Stn, VA at 12:00Z on 2007-04-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 223 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
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
130 J/kg
Mixed-layer CIN
-35 J/kg
Mixed-layer LCL
479 m above ground
0-6 km bulk shear
45 kt
0-1 km storm-relative helicity
223 m²/s²
0-3 km storm-relative helicity
224 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.

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SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 27, 12:01 PM EDTSevere Thunderstorm WatchSPCDorchester, Somerset, Wicomico, Worcester5 hr
Apr 26, 8:26 PM EDTMesoscale DiscussionSPCCherokee, Graham94 min
Apr 27, 11:29 AM EDTMesoscale DiscussionSPCBeaufort, Bertie, Bladen, Brunswick, Camden, Carteret and 36 more61 min
Apr 27, 7:33 PM EDTMesoscale DiscussionSPCAccomack, Gloucester, Lancaster, Mathews, Middlesex, Northampton and 2 more87 min

Nearby

Mesoscale Discussions in Virginia, 2007Mesoscale Discussions in North Carolina, 2007Mesoscale Discussions in Maryland, 2007Every mesoscale discussion in 2007

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.