Alert archive / North Carolina / Mesoscale Discussions in 2011

Mesoscale Discussion 941

May 24, 201129 counties in North Carolina; 14 counties in Virginia

The Storm Prediction Center issued this mesoscale discussion at May 24, 2011, 8:40 PM EDT for 29 counties in North Carolina; 14 counties in Virginia. It was in force for 65 min.

The area

The outline as issued.

The facts

Issued
May 24, 2011, 8:40 PM EDT (00:40 UTC)
Expired
May 24, 2011, 9:45 PM EDT
In force
65 min
Issued by
the Storm Prediction Center
All 43 counties

Beaufort County, NC, Bertie County, NC, Camden County, NC, Chowan County, NC, Currituck County, NC, Durham County, NC, Edgecombe County, NC, Franklin County, NC, Gates County, NC, Granville County, NC, Greene County, NC, Halifax County, NC, Hertford County, NC, Hyde County, NC, Johnston County, NC, Lenoir County, NC, Martin County, NC, Nash County, NC, Northampton County, NC, Pasquotank County, NC, Perquimans County, NC, Pitt County, NC, Tyrrell County, NC, Vance County, NC, Wake County, NC, Warren County, NC, Washington County, NC, Wayne County, NC, Wilson County, NC, Brunswick County, VA, City of Chesapeake, VA, City of Emporia, VA, City of Franklin, VA, City of Portsmouth, VA, City of Suffolk, VA, Dinwiddie County, VA, Greensville County, VA, Isle of Wight County, VA, Lunenburg County, VA, Mecklenburg County, VA, Southampton County, VA, Surry County, VA, Sussex County, VA

The radar

The Raleigh/Durham radar (KRAX), 94 km from the middle of the area, began a volume at 00:41 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 00:00Z, 0.7 hours before the alert went out and 165 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 00:00Z on 2011-05-25Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1721 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 00:00Z on 2011-05-25The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 88 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
1721 J/kg
Mixed-layer CIN
-123 J/kg
Mixed-layer LCL
1412 m above ground
0-6 km bulk shear
32 kt
0-1 km storm-relative helicity
88 m²/s²
0-3 km storm-relative helicity
115 m²/s²
Significant tornado parameter
0.2
Supercell composite
2.7

Open this sounding in Storm Lab

The text

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

501 
ACUS11 KWNS 250041
SWOMCD
SPC MCD 250040
NCZ000-VAZ000-250145-

MESOSCALE DISCUSSION 0941
NWS STORM PREDICTION CENTER NORMAN OK
0740 PM CDT TUE MAY 24 2011

AREAS AFFECTED...FAR SERN VA...ERN NC

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 250040Z - 250145Z

CONVECTIVE TRENDS WILL CONTINUE TO BE MONITORED OVER FAR SERN VA AND
ERN NC FOR INCREASING SVR WEATHER THREAT DURING THE EVENING/EARLY
NIGHT. A WW COULD BE NEEDED IF A BOWING MCS DEVELOPS.

QLCS WAS LOCATED OVER SRN VA/NRN NC AT 0030Z...WITH THE LEADING EDGE
BEGINNING TO ACCELERATE EWD AT CLOSE TO 40 KT. RUC FORECAST
SOUNDINGS AND 00Z GSO AND MHX RAOBS INDICATE 1000-2500 J/KG OF
MUCAPE LOCATED ABOVE A SLIGHTLY STABLE BOUNDARY LAYER. THIS
INSTABILITY COMBINED WITH UPPER IMPULSE MOVING INTO WRN VA/NC MAY
AID MCS MAINTENANCE INTO PART OF THE NIGHT AS THE SYSTEM APPROACHES
PORTIONS OF SERN VA/ERN NC. GIVEN THE STABLE BOUNDARY LAYER
PROFILES...IT IS UNCERTAIN WHETHER A DAMAGING WIND THREAT WILL
PERSIST. HOWEVER...CONVECTIVE AND ENVIRONMENTAL TRENDS WILL CONTINUE
TO BE MONITORED FOR SIGNS OF AN INCREASING SVR WEATHER THREAT.

..GARNER.. 05/25/2011

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

ATTN...WFO...AKQ...MHX...RAH...RNK...

LAT...LON   35827907 37067850 37207690 36687589 35207607 35197787
            35827907

Nearby

Mesoscale Discussions in North 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.