Alert archive / North Carolina / Mesoscale Discussions in 2011

Mesoscale Discussion 460

April 16, 201140 counties in North Carolina; 12 counties in South Carolina; 39 counties in Virginia

The Storm Prediction Center issued this mesoscale discussion at Apr 16, 2011, 4:49 PM EDT for 40 counties in North Carolina; 12 counties in South Carolina; 39 counties in Virginia. It was in force for 86 min.

The area

The outline as issued.

The facts

Issued
Apr 16, 2011, 4:49 PM EDT (20:49 UTC)
Expired
Apr 16, 2011, 6:15 PM EDT
In force
86 min
Issued by
the Storm Prediction Center
All 91 counties

Beaufort County, NC, Bertie County, NC, Bladen County, NC, Brunswick County, NC, Camden County, NC, Carteret County, NC, Chowan County, NC, Columbus County, NC, Craven County, NC, Cumberland County, NC, Currituck County, NC, Dare County, NC, Duplin County, NC, Edgecombe County, NC, Franklin County, NC, Gates County, NC, Greene County, NC, Halifax County, NC, Hertford County, NC, Hyde County, NC, Johnston County, NC, Jones County, NC, Lenoir County, NC, Martin County, NC, Nash County, NC, New Hanover County, NC, Northampton County, NC, Onslow County, NC, Pamlico County, NC, Pasquotank County, NC, Pender County, NC, Perquimans County, NC, Pitt County, NC, Robeson County, NC, Sampson County, NC, Tyrrell County, NC, Warren County, NC, Washington County, NC, Wayne County, NC, Wilson County, NC, Beaufort County, SC, Berkeley County, SC, Charleston County, SC, Colleton County, SC, Dillon County, SC, Dorchester County, SC, Florence County, SC, Georgetown County, SC, Horry County, SC, Jasper County, SC, Marion County, SC, Williamsburg County, SC, Brunswick County, VA, Caroline 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, Hanover 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, Middlesex County, VA, New Kent County, VA, Prince George County, VA, Richmond County, VA, Southampton County, VA, Surry County, VA, Sussex County, VA, York County, VA

The radar

The Morehead City radar (KMHX), 78 km from the middle of the area, began a volume at 20:52 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, 8.8 hours before the alert went out and 78 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 2011-04-16Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 7 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 2011-04-16The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 201 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
7 J/kg
Mixed-layer CIN
-6 J/kg
Mixed-layer LCL
824 m above ground
0-6 km bulk shear
47 kt
0-1 km storm-relative helicity
201 m²/s²
0-3 km storm-relative helicity
308 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

054 
ACUS11 KWNS 162050
SWOMCD
SPC MCD 162049
NCZ000-VAZ000-SCZ000-162215-

MESOSCALE DISCUSSION 0460
NWS STORM PREDICTION CENTER NORMAN OK
0349 PM CDT SAT APR 16 2011

AREAS AFFECTED...PORTIONS S-CENTRAL/SERN VA...CENTRAL/ERN NC...ERN
SC.

CONCERNING...TORNADO WATCH 150...

VALID 162049Z - 162215Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 150 CONTINUES.

BKN BAND OF SVR CONVECTION...INCLUDING A FEW CYCLIC/LONG-TRACKED
SUPERCELLS WITH HISTORY OF DESTRUCTIVE TORNADOES...IS MOVING NEWD
ACROSS WW IN SRN VA AND CENTRAL-ERN NC.  CONDITIONS REMAIN QUITE
FAVORABLE FOR TORNADIC SUPERCELLS TO PERSIST EWD ACROSS COASTAL
PLAIN TO TIDEWATER...CONTINUING ONGOING REGIME OF
DAMAGING/SIGNIFICANT TORNADO POTENTIAL FOR A FEW MORE HOURS AT
LEAST.

SFC ANALYSIS INDICATES WARM FRONT LIFTING NWD ACROSS CENTRAL AND
SERN VA...WHICH WILL LEAVE ENTIRE WW IN SFC-BASED EFFECTIVE INFLOW
SHORTLY.  STG PRESSURE FALLS CONTINUE AHEAD OF PRIMARY TSTM
CORRIDOR...ARE HELPING TO MAINTAIN RELATIVELY BACKED SFC
WINDS...ENLARGED LOW-LEVEL HODOGRAPHS AND FAVORABLE STORM-RELATIVE
INFLOW.  ALTHOUGH RDU VWP HAS BEEN AFFECTED BY GUST FRONT FROM
EARLIER TORNADIC SUPERCELL IN THAT AREA...PRE-STORM
PROFILE...INTERPOLATED WITH VWP AT AKQ...APPEAR TO REPRESENT
KINEMATIC ENVIRONMENT WELL OVER NERN NC AND SERN VA.  THOSE
DATA...ALONG WITH MODIFIED RUC SOUNDINGS...INDICATE 0-1 KM SRH
AROUND 500 J/KG...TRENDING TO AROUND 250-300 J/KG OVER EXTREME ERN
SC...WITH 0-3 KM SRH UP TO 900 J/KG AND 0-1 KM SHEAR MAGNITUDES
35-40 KT IN SERN VA NEAR WARM FRONT.  SUCH LOW-LEVEL SHEAR AND SRH
ARE EXTREME FOR ANY AIR MASS WITH SFC-BASED PARCELS...AND ARE
SUPERIMPOSED ON 50-60 KT EFFECTIVE SHEAR MAGNITUDES.  MLCAPE WILL
RANGE FROM AROUND 500 J/KG OVER SERN VA TO NEAR 1500 J/KG OVER SERN
NC AND ERN SC THROUGH 23Z.

..EDWARDS.. 04/16/2011

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...AKQ...MHX...LWX...RAH...ILM...CHS...CAE...

LAT...LON   33418028 35167890 36867810 38067767 37987648 37487610
            36967597 36307580 35717547 35357549 35157553 35207567
            35017608 34657650 34507650 34627661 34627709 34237775
            33677800 33897806 33727884 33177922 32807982 32438044
            32148100 32608114 33418028

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 16, 5:57 AM EDTTornado WatchSPCAlexander, Cabarrus, Catawba, Cleveland, Davie, Gaston and 9 more8 hr
Apr 16, 10:39 AM EDTMesoscale DiscussionSPCAlamance, Anson, Bertie, Bladen, Brunswick, Cabarrus and 52 more2 hr
Apr 16, 12:02 PM EDTTornado Watch PDSSPCAlamance, Anson, Beaufort, Bertie, Bladen, Brunswick and 60 more11 hr
Apr 16, 12:16 PM EDTMesoscale DiscussionSPCBeaufort, Bertie, Bladen, Brunswick, Chowan, Columbus and 25 more59 min
Apr 16, 2:28 PM EDTMesoscale DiscussionSPCAlamance, Beaufort, Bertie, Bladen, Brunswick, Camden and 49 more92 min
Apr 16, 6:59 PM EDTMesoscale DiscussionSPCBeaufort, Bertie, Bladen, Brunswick, Camden, Carteret and 28 more91 min
Apr 16, 5:09 AM EDTMesoscale DiscussionSPCAbbeville, Aiken, Anderson, Chester, Edgefield, Fairfield and 10 more96 min
Apr 16, 12:52 PM EDTMesoscale DiscussionSPCAccomack, Albemarle, Amherst, Arlington, Augusta, Botetourt and 51 more113 min
Apr 16, 1:29 PM EDTTornado WatchSPCAlbemarle, Arlington, Augusta, Clarke, Culpeper, Fairfax and 28 more8 hr
Apr 16, 4:29 PM EDTMesoscale DiscussionSPCArlington, Clarke, Culpeper, Fairfax, Fauquier, Frederick and 20 more31 min
Apr 16, 6:38 PM EDTMesoscale DiscussionSPCAlbemarle, Arlington, Augusta, Clarke, Culpeper, Fairfax and 28 more97 min

Nearby

Mesoscale Discussions in North Carolina, 2011Mesoscale Discussions in Virginia, 2011Mesoscale Discussions in South Carolina, 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.