Alert archive / North Carolina / Mesoscale Discussions in 2011

Mesoscale Discussion 784

May 14, 201129 counties in North Carolina; Dillon County, Marion County, South Carolina; City of Chesapeake, Virginia

The Storm Prediction Center issued this mesoscale discussion at May 14, 2011, 1:02 PM EDT for 29 counties in North Carolina; Dillon County, Marion County, South Carolina; City of Chesapeake, Virginia. It was in force for 118 min.

The area

The outline as issued.

The facts

Issued
May 14, 2011, 1:02 PM EDT (17:02 UTC)
Expired
May 14, 2011, 3:00 PM EDT
In force
118 min
Issued by
the Storm Prediction Center
All 32 counties

Beaufort County, NC, Bertie County, NC, Bladen County, NC, Camden County, NC, Chowan County, NC, Columbus County, NC, Craven County, NC, Cumberland County, NC, Duplin County, NC, Edgecombe County, NC, Gates County, NC, Greene County, NC, Hertford County, NC, Hyde County, NC, Jones County, NC, Lenoir County, NC, Martin 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, Washington County, NC, Wayne County, NC, Wilson County, NC, Dillon County, SC, Marion County, SC, City of Chesapeake, VA

The radar

The Raleigh/Durham radar (KRAX), 80 km from the middle of the area, began a volume at 17:05 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

Newport, NC (KMHX), launched 12:00Z, 5.0 hours before the alert went out and 99 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 2011-05-14Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 618 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 2011-05-14The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 51 square meters per square second.1939Sfc1 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
618 J/kg
Mixed-layer CIN
-114 J/kg
Mixed-layer LCL
824 m above ground
0-6 km bulk shear
25 kt
0-1 km storm-relative helicity
51 m²/s²
0-3 km storm-relative helicity
85 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.5

Open this sounding in Storm Lab

The text

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

967 
ACUS11 KWNS 141702
SWOMCD
SPC MCD 141702 
NCZ000-VAZ000-SCZ000-141900-

MESOSCALE DISCUSSION 0784
NWS STORM PREDICTION CENTER NORMAN OK
1202 PM CDT SAT MAY 14 2011

AREAS AFFECTED...EXTREME NERN SC...ERN NC INTO EXTREME SERN VA

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 

VALID 141702Z - 141900Z

MULTICELL STORMS EXPECTED TO DEVELOP ACROSS THE ERN CAROLINAS INTO
SERN VA. A FEW STORMS WILL BECOME CAPABLE OF PRODUCING ISOLATED
LOCALLY STRONG TO DAMAGING WIND GUSTS AND HAIL. AREA IS BEING
MONITORED FOR A SEVERE THUNDERSTORM WATCH.

EARLY THIS AFTERNOON STRONG DIABATIC WARMING OF THE MOIST BOUNDARY
LAYER IS RESULTING IN DESTABILIZATION FROM THE ERN CAROLINAS INTO
SERN VA. LAPSE RATES ARE MODEST...BUT COOL TEMPERATURES ALOFT WITH
THE UPPER LOW CIRCULATION...LOW 80S SURFACE TEMPERATURES AND UPPER
60S DEWPOINTS ARE RESULTING IN 2000-2500 J/KG MLCAPE. WV AND RUC
ANALYSIS INDICATE A WEAK IMPULSE EJECTING NEWD THROUGH THE
CAROLINAS...AND FURTHER DIABATIC WARMING WILL LIKELY ERODE THE CAP
SUFFICIENTLY FOR STORMS TO DEVELOP ALONG THE SEA BREEZE AND SUBTLE
DIFFERENTIAL HEATING BOUNDARIES. MODEST 20-30 KT SWLY FLOW EXISTS
OVER THE ERN CAROLINAS DOWNSTREAM FROM UPPER TROUGH AXIS WITH WEAK
EFFECTIVE SHEAR SUPPORTIVE OF MULTICELLS.

..DIAL.. 05/14/2011

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

ATTN...WFO...AKQ...MHX...RAH...ILM...

LAT...LON   34737952 35747796 36487717 36737634 36557600 35737589
            35137632 34187840 33847964 34737952

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 13, 9:00 PM EDTMesoscale DiscussionSPCAlamance, Anson, Cabarrus, Chatham, Davidson, Davie and 14 more30 min
May 14, 1:44 PM EDTSevere Thunderstorm WatchSPCBeaufort, Bertie, Bladen, Brunswick, Camden, Carteret and 35 more8 hr
May 14, 4:21 PM EDTMesoscale DiscussionSPCBeaufort, Bertie, Bladen, Chowan, Columbus, Craven and 31 more84 min
May 14, 7:32 PM EDTMesoscale DiscussionSPCBeaufort, Bertie, Bladen, Brunswick, Camden, Chowan and 37 more58 min
May 14, 4:30 PM EDTMesoscale DiscussionSPCAbbeville, Aiken, Allendale, Bamberg, Barnwell, Calhoun and 10 more30 min
May 14, 4:41 PM EDTSevere Thunderstorm WatchSPCAiken, Allendale, Bamberg, Barnwell, Beaufort, Berkeley and 10 more4 hr
May 14, 6:44 PM EDTMesoscale DiscussionSPCAllendale, Bamberg, Barnwell, Beaufort, Berkeley, Charleston and 7 more61 min

Nearby

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