Alert archive / North Carolina / Mesoscale Discussions in 2011

Mesoscale Discussion 381

April 9, 201125 counties in North Carolina; Carter County, Johnson County, Sullivan County, Tennessee; 11 counties in Virginia

The Storm Prediction Center issued this mesoscale discussion at Apr 9, 2011, 3:23 AM EDT for 25 counties in North Carolina; Carter County, Johnson County, Sullivan County, Tennessee; 11 counties in Virginia. It was in force for 67 min.

The area

The outline as issued.

The facts

Issued
Apr 9, 2011, 3:23 AM EDT (07:23 UTC)
Expired
Apr 9, 2011, 4:30 AM EDT
In force
67 min
Issued by
the Storm Prediction Center
All 39 counties

Alexander County, NC, Alleghany County, NC, Ashe County, NC, Avery County, NC, Burke County, NC, Cabarrus County, NC, Caldwell County, NC, Catawba County, NC, Davidson County, NC, Davie County, NC, Forsyth County, NC, Guilford County, NC, Iredell County, NC, Lincoln County, NC, Montgomery County, NC, Moore County, NC, Randolph County, NC, Rockingham County, NC, Rowan County, NC, Stanly County, NC, Stokes County, NC, Surry County, NC, Watauga County, NC, Wilkes County, NC, Yadkin County, NC, Carter County, TN, Johnson County, TN, Sullivan County, TN, Bland County, VA, Carroll County, VA, City of Bristol, VA, City of Galax, VA, Grayson County, VA, Patrick County, VA, Pulaski County, VA, Russell County, VA, Smyth County, VA, Washington County, VA, Wythe County, VA

The radar

The Roanoke radar (KFCX), 110 km from the middle of the area, began a volume at 07:26 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

Greensboro/Hi Pt, NC (KGSO), launched 00:00Z, 7.4 hours before the alert went out and 105 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.

537 
ACUS11 KWNS 090723
SWOMCD
SPC MCD 090723 
NCZ000-VAZ000-WVZ000-TNZ000-090830-

MESOSCALE DISCUSSION 0381
NWS STORM PREDICTION CENTER NORMAN OK
0223 AM CDT SAT APR 09 2011

AREAS AFFECTED...SW VA...WRN/CNTRL NC

CONCERNING...SEVERE THUNDERSTORM WATCH 110...

VALID 090723Z - 090830Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 110
CONTINUES.

...WIDELY SCATTERED TSTMS PRODUCING MARGINALLY SEVERE HAIL
DIMINISHING...

WNWLY H9-H85 JET AXIS HAS CONTINUED TO WEAKEN AND SHIFT SWD AS WEAK
MID-LEVEL WAVE PASSES BY THE MID-ATLANTIC REGION EARLY THIS MORNING.
GENERATION POINT TO THE ELEVATED UPDRAFTS HAS CONSEQUENTLY SHIFTED
SEWD INTO NERN TN AND WRN/CNTRL NC...BEYOND SEVERE WATCH 110. 
INSPECTION OF RUC FORECAST SOUNDINGS SUGGEST THAT MODEST MID-LEVEL
LAPSE RATES OF 6.5-6.8 C PER KM AND WEAK AMOUNTS OF WARM ADVECTION
MAY AID IN BRIEF STORM INTENSIFICATION AND MARGINALLY SEVERE HAIL. 
HOWEVER...IT APPEARS THE SVR THREAT IS WANING WITH TIME AND
PROBABILITY FOR NEW WATCHES/EXTENSIONS IS LESS THAN 20 PERCENT.

..RACY.. 04/09/2011

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

ATTN...WFO...RAH...RNK...GSP...MRX...

LAT...LON   37378102 36437975 35277910 35197987 35328081 35538165
            35898209 36498230 36878250 37108147 37378102

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 8, 9:10 PM EDTMesoscale DiscussionSPCAlamance, Caswell, Chatham, Davidson, Durham, Forsyth and 11 more65 min
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, 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
Apr 9, 7:41 AM EDTMesoscale DiscussionSPCClay, Fentress, Jackson, Macon, Montgomery, Overton and 6 more2 hr
Apr 9, 8:25 AM EDTSevere Thunderstorm WatchSPCClay, Jackson, Macon, Montgomery, Overton, Pickett and 4 more6 hr
Apr 9, 12:07 PM EDTMesoscale DiscussionSPCCampbell, Clay, Cumberland, Fentress, Jackson, Morgan and 5 more83 min

Nearby

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