Alert archive / Virginia / Mesoscale Discussions in 2008

Mesoscale Discussion 839

May 9, 200824 counties in North Carolina; 31 counties in Virginia

The Storm Prediction Center issued this mesoscale discussion at May 9, 2008, 8:29 AM EDT for 24 counties in North Carolina; 31 counties in Virginia. It was in force for 61 min.

The area

The outline as issued.

The facts

Issued
May 9, 2008, 8:29 AM EDT (12:29 UTC)
Expired
May 9, 2008, 9:30 AM EDT
In force
61 min
Issued by
the Storm Prediction Center
All 55 counties

Beaufort County, NC, Bertie County, NC, Camden County, NC, Carteret County, NC, Chowan County, NC, Craven County, NC, Currituck County, NC, Edgecombe County, NC, Gates County, NC, Greene County, NC, Halifax 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, 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, Dinwiddie County, VA, Gloucester County, VA, Greensville County, VA, Henrico County, VA, Isle of Wight County, VA, James City County, VA, Lancaster County, VA, Mathews County, VA, Middlesex County, VA, New Kent County, VA, Northampton County, VA, Prince George County, VA, Southampton County, VA, Surry County, VA, Sussex County, VA, York County, VA

The radar

The Norfolk radar (KAKQ), 80 km from the middle of the area, began a volume at 12:29 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

Newport, NC (KMHX), launched 12:00Z, 0.5 hours before the alert went out and 166 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, Newport, NC at 12:00Z on 2008-05-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 822 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, Newport, NC at 12:00Z on 2008-05-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 252 square meters per square second.193958Sfc1 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
822 J/kg
Mixed-layer CIN
-24 J/kg
Mixed-layer LCL
884 m above ground
0-6 km bulk shear
40 kt
0-1 km storm-relative helicity
252 m²/s²
0-3 km storm-relative helicity
273 m²/s²
Significant tornado parameter
0.9
Supercell composite
9.8

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
May 8, 8:38 PM EDTTornado WatchSPCDurham, Franklin, Granville, Lee, Vance, Wake and 1 more6 hr
May 8, 9:47 PM EDTMesoscale DiscussionSPCAlamance, Cabarrus, Caswell, Chatham, Davidson, Davie and 20 more58 min
May 9, 12:06 AM EDTMesoscale DiscussionSPCAlamance, Caswell, Durham, Granville, Guilford, Orange and 2 more54 min
May 9, 2:32 AM EDTMesoscale DiscussionSPCAlamance, Bertie, Camden, Caswell, Chatham, Chowan and 27 more88 min
May 9, 3:00 AM EDTTornado WatchSPCAlamance, Beaufort, Bertie, Camden, Caswell, Chatham and 34 more8 hr
May 9, 5:04 AM EDTMesoscale DiscussionSPCBertie, Camden, Chatham, Chowan, Currituck, Durham and 25 more56 min
May 9, 5:56 AM EDTMesoscale DiscussionSPCBrunswick, Columbus2 hr
May 9, 6:37 AM EDTMesoscale DiscussionSPCBertie, Camden, Chowan, Currituck, Edgecombe, Franklin and 11 more53 min
May 9, 7:18 PM EDTMesoscale DiscussionSPCDickenson, Lee, Scott, Wise, City of Norton57 min

Nearby

Mesoscale Discussions in Virginia, 2008Mesoscale Discussions in North Carolina, 2008Every mesoscale discussion 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.