Alert archive / North Carolina / Mesoscale Discussions in 2011

Mesoscale Discussion 375

April 8, 201117 counties in North Carolina

The Storm Prediction Center issued this mesoscale discussion at Apr 8, 2011, 9:10 PM EDT for 17 counties in North Carolina. It was in force for 65 min.

The area

The outline as issued.

The facts

Issued
Apr 8, 2011, 9:10 PM EDT (01:10 UTC)
Expired
Apr 8, 2011, 10:15 PM EDT
In force
65 min
Issued by
the Storm Prediction Center

Counties Alamance County, NC, Caswell County, NC, Chatham County, NC, Davidson County, NC, Durham County, NC, Forsyth County, NC, Guilford County, NC, Harnett County, NC, Johnston County, NC, Lee County, NC, Orange County, NC, Randolph County, NC, Rockingham County, NC, Stokes County, NC, Wake County, NC, Wayne County, NC, Wilson County, NC

The radar

The Raleigh/Durham radar (KRAX), 66 km from the middle of the area, began a volume at 01:13 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 00:00Z, 1.2 hours before the alert went out and 69 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 00:00Z on 2011-04-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 42 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, Greensboro/Hi Pt, NC at 00:00Z on 2011-04-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 279 square meters per square second.1939587897Sfc1 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
42 J/kg
Mixed-layer CIN
-165 J/kg
Mixed-layer LCL
1618 m above ground
0-6 km bulk shear
56 kt
0-1 km storm-relative helicity
279 m²/s²
0-3 km storm-relative helicity
424 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.3

Open this sounding in Storm Lab

The text

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

348 
ACUS11 KWNS 090110
SWOMCD
SPC MCD 090110 
NCZ000-VAZ000-090215-

MESOSCALE DISCUSSION 0375
NWS STORM PREDICTION CENTER NORMAN OK
0810 PM CDT FRI APR 08 2011

AREAS AFFECTED...WRN/CNTRL NC

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 

VALID 090110Z - 090215Z

SEVERE THUNDERSTORMS PRIMARILY CAPABLE OF PRODUCING LARGE HAIL AND
LOCALLY DMGG WINDS ARE GRADUALLY PROGRESSING SEWD INTO N CNTRL
NC...AND MAY CONTINUE OVER THE NEXT FEW HOURS. HOWEVER...GIVEN
SOMEWHAT ISOLATED COVERAGE...A WW MAY NOT BECOME NECESSARY.

WEDGE FRONT HAS REMAINED NEARLY STATIONARY OVER NERN NC WWD THROUGH
MUCH OF CNTRL NC. A WEAK UPPER WAVE OBSERVED ON WV IMAGERY OVER WV
SWD THROUGH NRN AL HAS ALLOWED A SUBTLE WARM ADVECTION REGIME TO
MAINTAIN THE SEVERITY OF CONVECTION N OF THE WEDGE FRONT...DESPITE
THE ONSET OF RADIATIONAL COOLING. 00Z GSO SOUNDING INDICATES WEAK
INSTABILITY EAST OF THE APPALACHIANS...WHICH MAY IMPEDE STRONGER AND
MORE WIDESPREAD DEVELOPMENT. HOWEVER...STRONG WLY WINDS HAVE ALLOWED
AN EML TO SPREAD TO THE CAROLINAS...WITH STEEP MID LEVEL LAPSE RATES
AND STRONG DEEP-LAYER WIND PROFILES SUPPORTING LARGE HAIL IN ANY
ELEVATED STORMS THAT CAN DEVELOP. AN ISOLATED TORNADO CANNOT BE
RULED OUT IN CLOSER PROXIMITY TO THE WEDGE FRONT.

..HURLBUT.. 04/09/2011

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

ATTN...WFO...MHX...RAH...RNK...GSP...

LAT...LON   36608026 36307877 35657775 35197767 35147860 35467977
            35908041 36608026

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 8, 11:07 PM EDTSevere Thunderstorm WatchSPCAlleghany, Ashe, Rockingham, Stokes, Surry, Watauga and 2 more6 hr
Apr 9, 12:42 AM EDTMesoscale DiscussionSPCAlamance, Alexander, Alleghany, Ashe, Avery, Cabarrus and 23 more93 min
Apr 9, 3:23 AM EDTMesoscale DiscussionSPCAlexander, Alleghany, Ashe, Avery, Burke, Cabarrus and 19 more67 min
Apr 9, 12:34 PM EDTSevere Thunderstorm WatchSPCAlleghany, Ashe, Avery, Buncombe, Burke, Caldwell and 17 more4 hr
Apr 9, 2:00 PM EDTTornado WatchSPCAlleghany, Ashe, Avery, Buncombe, Burke, Caldwell and 17 more7 hr
Apr 9, 2:44 PM EDTSevere Thunderstorm WatchSPCAlexander, Anson, Cabarrus, Catawba, Cleveland, Davie and 7 more6 hr
Apr 9, 4:21 PM EDTMesoscale DiscussionSPCAshe, Avery, Buncombe, Burke, Caldwell, Cherokee and 15 more84 min
Apr 9, 5:36 PM EDTMesoscale DiscussionSPCCleveland, Gaston, Lincoln, Mecklenburg, Polk, Rutherford and 1 more54 min
Apr 9, 6:16 PM EDTTornado WatchSPCBuncombe, Burke, Cleveland, Gaston, Haywood, Henderson and 10 more6 hr
Apr 9, 7:59 PM EDTMesoscale DiscussionSPCAnson, Buncombe, Burke, Cabarrus, Catawba, Cleveland and 13 more61 min

Nearby

Mesoscale Discussions in North 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.