Alert archive / North Carolina / Mesoscale Discussions in 2014

Mesoscale Discussion 607

May 15, 201439 counties in North Carolina; 19 counties in South Carolina; 20 counties in Virginia

The Storm Prediction Center issued this mesoscale discussion at May 15, 2014, 8:29 AM EDT for 39 counties in North Carolina; 19 counties in South Carolina; 20 counties in Virginia. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
May 15, 2014, 8:29 AM EDT (12:29 UTC)
Expired
May 15, 2014, 10:30 AM EDT
In force
2 hr
Issued by
the Storm Prediction Center
Chance of a watch
60%
All 78 counties

Alamance County, NC, Anson County, NC, Bladen County, NC, Brunswick County, NC, Cabarrus County, NC, Caswell County, NC, Chatham County, NC, Columbus County, NC, Cumberland County, NC, Davidson County, NC, Davie County, NC, Durham County, NC, Forsyth County, NC, Franklin County, NC, Granville County, NC, Guilford County, NC, Harnett County, NC, Hoke County, NC, Johnston County, NC, Lee County, NC, Montgomery County, NC, Moore County, NC, Nash County, NC, Orange County, NC, Person County, NC, Randolph County, NC, Richmond County, NC, Robeson County, NC, Rockingham County, NC, Rowan County, NC, Sampson County, NC, Scotland County, NC, Stanly County, NC, Stokes County, NC, Union County, NC, Vance County, NC, Wake County, NC, Warren County, NC, Wayne County, NC, Berkeley County, SC, Calhoun County, SC, Charleston County, SC, Chesterfield County, SC, Clarendon County, SC, Colleton County, SC, Darlington County, SC, Dillon County, SC, Dorchester County, SC, Florence County, SC, Georgetown County, SC, Horry County, SC, Kershaw County, SC, Lee County, SC, Marion County, SC, Marlboro County, SC, Orangeburg County, SC, Sumter County, SC, Williamsburg County, SC, Appomattox County, VA, Bedford County, VA, Campbell County, VA, Charlotte County, VA, City of Danville, VA, City of Lynchburg, VA, City of Martinsville, VA, City of Roanoke, VA, City of Salem, VA, Floyd County, VA, Franklin County, VA, Halifax County, VA, Henry County, VA, Lunenburg County, VA, Mecklenburg County, VA, Montgomery County, VA, Patrick County, VA, Pittsylvania County, VA, Prince Edward County, VA, Roanoke County, VA

The radar

The Wilmington radar (KLTX), 133 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 watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

The nearest sounding before it

Greensboro/Hi Pt, NC (KGSO), launched 12:00Z, 0.5 hours before the alert went out and 149 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, Greensboro/Hi Pt, NC at 12:00Z on 2014-05-15Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 114 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Greensboro/Hi Pt, NC at 12:00Z on 2014-05-15The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 133 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
114 J/kg
Mixed-layer CIN
-14 J/kg
Mixed-layer LCL
582 m above ground
0-6 km bulk shear
39 kt
0-1 km storm-relative helicity
133 m²/s²
0-3 km storm-relative helicity
130 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

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

125 
ACUS11 KWNS 151229
SWOMCD
SPC MCD 151229 
NCZ000-VAZ000-SCZ000-151430-

MESOSCALE DISCUSSION 0607
NWS STORM PREDICTION CENTER NORMAN OK
0729 AM CDT THU MAY 15 2014

AREAS AFFECTED...SC INTO NC

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 

VALID 151229Z - 151430Z

PROBABILITY OF WATCH ISSUANCE...60 PERCENT

SUMMARY...STORMS ARE EXPECTED TO GRADUALLY INCREASE IN COVERAGE THIS
MORNING...AND A TORNADO WATCH COULD BE REQUIRED BY 14-15Z.

DISCUSSION...A SLOW-MOVING LINE OF THUNDERSTORMS ASSOCIATED WITH A
LEADING SHORTWAVE FEATURE WILL CONTINUE TO AFFECT CNTRL
SC...NC...AND VA THIS MORNING. SOME OF THESE CELLS HAVE SHOWN SIGNS
OF WEAK ROTATION...BUT NONE HAVE BEEN LONG LIVED YET DUE TO WEAK
FORCING.

AHEAD OF THE LINE...A VERY MOIST AIR MASS CONTINUES TO SPREAD NWD
WITH DEWPOINTS INTO THE LOWER 70S F. THE 12Z CHS SOUNDING INDICATED
AROUND 1500 J/KG MLCAPE AND NO INHIBITION....WHILE FARTHER N...THE
RNK SOUNDING SHOWED A FAVORABLE SUPERCELL/TORNADO HODOGRAPH
CONDITIONAL ON INSTABILITY. 

THE SLOW UPPER TROUGH MOVEMENT WILL RESULT IN MOIST SELY SURFACE
WINDS ACROSS THE REGION. AS POCKETS OF HEATING OCCUR ALONG WITH SOME
MOISTURE ADVECTION...THERE SHOULD BE A CORRESPONDING THREAT OF
TORNADOES....BOTH WITH BROKEN CELLS WITHIN THE LEADING LINE...AND
WITH NEW ACTIVITY THAT FORMS AHEAD. WHILE CONDITIONS MAY NOT FAVOR
PARTICULARLY STRONG TORNADOES...SEVERAL TORNADOES WILL BE POSSIBLE
TODAY...MOST LIKELY FOCUSED IN A NARROW N-S ZONE FROM ERN SC INTO
CNTRL NC AND VA.

..JEWELL/CORFIDI.. 05/15/2014

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

ATTN...WFO...AKQ...MHX...RAH...ILM...RNK...CHS...CAE...GSP...

LAT...LON   32837944 32548000 32508045 32788086 33388088 34448065
            35568061 36768070 37338034 37517976 37597924 37327831
            36717795 35857792 34247802 33807822 33607890 33127914
            32837944

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 15, 12:14 AM EDTMesoscale DiscussionSPCBuncombe, Haywood, Henderson, Jackson, Macon, Madison and 4 more91 min
May 15, 11:56 AM EDTSevere Thunderstorm WatchSPCAlamance, Beaufort, Bertie, Bladen, Brunswick, Carteret and 38 more8 hr
May 15, 3:22 PM EDTMesoscale DiscussionSPCBeaufort, Bertie, Bladen, Brunswick, Carteret, Chatham and 35 more53 min
May 15, 6:24 PM EDTMesoscale DiscussionSPCAlamance, Beaufort, Bertie, Bladen, Brunswick, Carteret and 37 more96 min
May 15, 6:55 PM EDTMesoscale DiscussionSPCBeaufort, Berkeley, Calhoun, Charleston, Chesterfield, Clarendon and 13 more2 hr

Nearby

Mesoscale Discussions in North Carolina, 2014Mesoscale Discussions in Virginia, 2014Mesoscale Discussions in South Carolina, 2014Every mesoscale discussion in 2014

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.