Alert archive / North Carolina / Mesoscale Discussions in 2012

Mesoscale Discussion 1445

July 9, 201213 counties in North Carolina; 11 counties in Virginia

The Storm Prediction Center issued this mesoscale discussion at Jul 9, 2012, 5:53 PM EDT for 13 counties in North Carolina; 11 counties in Virginia. It was in force for 97 min.

The area

The outline as issued.

The facts

Issued: Jul 9, 2012, 5:53 PM EDT (21:53 UTC)
Expired: Jul 9, 2012, 7:30 PM EDT
In force: 97 min
Issued by: the Storm Prediction Center

All 24 counties

Alamance County, NC, Alleghany County, NC, Caswell County, NC, Davie County, NC, Forsyth County, NC, Guilford County, NC, Orange County, NC, Person County, NC, Rockingham County, NC, Stokes County, NC, Surry County, NC, Wilkes County, NC, Yadkin County, NC, Carroll County, VA, City of Danville, VA, City of Galax, VA, City of Martinsville, VA, Floyd County, VA, Franklin County, VA, Grayson County, VA, Halifax County, VA, Henry County, VA, Patrick County, VA, Pittsylvania County, VA

The radar

The Roanoke radar (KFCX), 47 km from the middle of the area, began a volume at 21:55 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 12:00Z, 9.9 hours before the alert went out and 63 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 1054 J/kg
Mixed-layer CIN: -119 J/kg
Mixed-layer LCL: 1186 m above ground
0-6 km bulk shear: 17 kt
0-1 km storm-relative helicity: 23 m²/s²
0-3 km storm-relative helicity: 31 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

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

416 
ACUS11 KWNS 092153
SWOMCD
SPC MCD 092153 
VAZ000-NCZ000-092330-

MESOSCALE DISCUSSION 1445
NWS STORM PREDICTION CENTER NORMAN OK
0453 PM CDT MON JUL 09 2012

AREAS AFFECTED...SWRN VA...NWRN NC

CONCERNING...SEVERE THUNDERSTORM WATCH 484...

VALID 092153Z - 092330Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 484
CONTINUES.

SUMMARY...MARGINAL SEVERE THREAT PERSISTS NEXT FEW HOURS...MAINLY
ERN PORTIONS OF WW 484.

DISCUSSION...REFLECTIVITY CORES WITHIN WW 484 HAVE LARGELY REMAINED
WEAKER RELATIVE TO TSTMS FARTHER E/SE IN WW 483. SEVERAL
INTERSECTING OUTFLOW BOUNDARIES APPARENT IN RADAR/SATELLITE IMAGERY
SHOULD REMAIN THE PRIMARY MECHANISM FOR FOCUSING RENEWED UPDRAFTS.
THIS APPEARS MOST PROBABLE IN ERN PORTIONS OF THE WW GIVEN POCKET OF
LOWER TO MIDDLE 90S SURFACE TEMPERATURES OBSERVED INVOF THE I-74/77
CORRIDORS NEAR/NW OF GSO. WITH ONLY MODEST DEEP-LAYER WLYS SAMPLED
IN THE FCX VWP /0-6 KM SHEAR AROUND 20 KT/...ACTIVITY SHOULD
STRUGGLE TO ORGANIZE...SUGGESTING LOCALIZED DOWNBURSTS SHOULD REMAIN
THE PRIMARY THREAT.

..GRAMS.. 07/09/2012

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

ATTN...WFO...AKQ...RAH...RNK...GSP...

LAT...LON   37218027 37037907 36717863 36307875 35657946 36038120
            36308149 36748122 36988096 37218027

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 9, 1:01 PM EDT	Mesoscale Discussion	SPC	Alexander, Avery, Buncombe, Burke, Caldwell, Catawba and 20 more	89 min
Jul 9, 1:36 PM EDT	Mesoscale Discussion	SPC	Alamance, Beaufort, Bertie, Caswell, Chatham, Chowan and 35 more	54 min
Jul 9, 2:59 PM EDT	Severe Thunderstorm Watch	SPC	Alamance, Beaufort, Bertie, Bladen, Camden, Carteret and 45 more	7 hr
Jul 9, 3:19 PM EDT	Severe Thunderstorm Watch	SPC	Alleghany, Ashe, Caswell, Rockingham, Stokes, Surry and 3 more	4 hr
Jul 9, 4:48 PM EDT	Mesoscale Discussion	SPC	Anson, Beaufort, Bertie, Bladen, Camden, Chowan and 39 more	87 min
Jul 9, 7:17 PM EDT	Mesoscale Discussion	SPC	Alamance, Beaufort, Bertie, Brunswick, Camden, Carteret and 25 more	88 min
Jul 9, 12:09 AM EDT	Mesoscale Discussion	SPC	Arlington, Caroline, Clarke, Culpeper, Fairfax, Fauquier and 21 more	96 min

Nearby

Mesoscale Discussions in North Carolina, 2012 Mesoscale Discussions in Virginia, 2012 Every mesoscale discussion in 2012

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.