Alert archive / Virginia / Mesoscale Discussions in 2008

Mesoscale Discussion 838

May 9, 20084 counties in Maryland; 17 counties in North Carolina; 42 counties in Virginia

The Storm Prediction Center issued this mesoscale discussion at May 9, 2008, 6:37 AM EDT for 4 counties in Maryland; 17 counties in North Carolina; 42 counties in Virginia. It was in force for 53 min.

The area

The outline as issued.

The facts

Issued
May 9, 2008, 6:37 AM EDT (10:37 UTC)
Expired
May 9, 2008, 7:30 AM EDT
In force
53 min
Issued by
the Storm Prediction Center
All 63 counties

Dorchester County, MD, Somerset County, MD, Wicomico County, MD, Worcester County, MD, Bertie County, NC, Camden County, NC, Chowan County, NC, Currituck County, NC, Edgecombe County, NC, Franklin County, NC, Gates County, NC, Halifax County, NC, Hertford County, NC, Martin County, NC, Nash County, NC, Northampton County, NC, Pasquotank County, NC, Perquimans County, NC, Warren County, NC, Washington 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, 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, Lunenburg County, VA, Mathews County, VA, Mecklenburg County, VA, Middlesex County, VA, New Kent County, VA, Northampton County, VA, Northumberland County, VA, Nottoway County, VA, Prince George County, VA, Richmond County, VA, Southampton County, VA, Surry County, VA, Sussex County, VA, York County, VA

The radar

The Norfolk radar (KAKQ), 42 km from the middle of the area, began a volume at 10:36 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, 10.6 hours before the alert went out and 175 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 00:00Z on 2008-05-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 5 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 00:00Z on 2008-05-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -40 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
5 J/kg
Mixed-layer CIN
-162 J/kg
Mixed-layer LCL
1002 m above ground
0-6 km bulk shear
37 kt
0-1 km storm-relative helicity
-40 m²/s²
0-3 km storm-relative helicity
34 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
May 8, 8:38 PM EDTTornado WatchSPCCalvert, Charles, Saint Mary's6 hr
May 8, 9:47 PM EDTMesoscale DiscussionSPCCalvert, Charles, Prince George's, Saint Mary's58 min
May 9, 2:32 AM EDTMesoscale DiscussionSPCCalvert, Charles, Saint Mary's, Somerset88 min
May 9, 3:00 AM EDTTornado WatchSPCCalvert, Saint Mary's8 hr
May 9, 12:06 AM EDTMesoscale DiscussionSPCAlamance, Caswell, Durham, Granville, Guilford, Orange and 2 more54 min
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, 8:29 AM EDTMesoscale DiscussionSPCBeaufort, Bertie, Camden, Carteret, Chowan, Craven and 18 more61 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, 2008Mesoscale Discussions in Maryland, 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.