Alert archive / North Carolina / Severe Thunderstorm Watches in 2016

Severe Thunderstorm Watch 352

July 7, 20169 counties in North Carolina

The Storm Prediction Center issued this severe thunderstorm watch at Jul 7, 2016, 7:21 PM EDT for 9 counties in North Carolina. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: Jul 7, 2016, 7:21 PM EDT (23:21 UTC)
Expired: Jul 7, 2016, 9:22 PM EDT
In force: 2 hr
Issued by: the Storm Prediction Center
Largest hail expected: 1 in
Strongest gust expected: 60 kt

Counties Buncombe County, NC, Graham County, NC, Haywood County, NC, Henderson County, NC, Jackson County, NC, Macon County, NC, Madison County, NC, Swain County, NC, Transylvania County, NC

The radar

The Knoxville radar (KMRX), 92 km from the middle of the area, began a volume at 23:22 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.

What SPC expected

The probabilities SPC published with the watch, for the watch area over its life.

Two or more tornadoes: 10%
One or more EF2 to EF5 tornadoes: 2%
Ten or more severe wind reports: 30%
One or more gusts of 65 knots or more: 10%
Ten or more severe hail reports: 20%
One or more hailstones of 2 inches or more: 5%
Six or more combined severe hail and wind reports: 50%

Warnings issued inside it

2 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

Issued	Product	Office	Counties	Lasted
Jul 7, 7:56 PM EDT	Severe Thunderstorm Warning	GSP	Jackson, Macon, Transylvania	49 min
Jul 7, 7:59 PM EDT	Severe Thunderstorm Warning	GSP	Buncombe, Haywood, Henderson, Jackson, Madison, Transylvania	46 min

Discussions around it

SPC mesoscale discussions over the same counties from four hours before the watch to its end.

Mesoscale Discussion 1194Jul 7, 6:37 PM EDT

The nearest sounding before it

Peachtre/Fal Fld, GA (KFFC), launched 12:00Z, 11.4 hours before the alert went out and 249 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: 1683 J/kg
Mixed-layer CIN: -60 J/kg
Mixed-layer LCL: 635 m above ground
0-6 km bulk shear: 15 kt
0-1 km storm-relative helicity: 12 m²/s²
0-3 km storm-relative helicity: -10 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

855 
WWUS20 KWNS 072320
SEL2  
SPC WW 072320
NCZ000-080300-

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 352
NWS STORM PREDICTION CENTER NORMAN OK
725 PM EDT THU JUL 7 2016

THE NWS STORM PREDICTION CENTER HAS ISSUED A

* SEVERE THUNDERSTORM WATCH FOR PORTIONS OF 
  WESTERN NORTH CAROLINA

* EFFECTIVE THIS THURSDAY EVENING FROM 725 PM UNTIL 1100 PM EDT.

* PRIMARY THREATS INCLUDE...
  ISOLATED DAMAGING WIND GUSTS TO 70 MPH POSSIBLE
  ISOLATED LARGE HAIL EVENTS TO 1 INCH IN DIAMETER POSSIBLE

SUMMARY...THUNDERSTORMS OVER EAST TN WILL TRACK INTO WESTERN NC
SOON...POSING A RISK OF LOCALLY DAMAGING WIND GUSTS FOR A COUPLE OF
HOURS.

THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 30
STATUTE MILES EITHER SIDE OF A LINE FROM 70 MILES WEST SOUTHWEST
OF ASHEVILLE NORTH CAROLINA TO 15 MILES NORTH NORTHEAST OF
ASHEVILLE NORTH CAROLINA.  FOR A COMPLETE DEPICTION OF THE WATCH
SEE THE ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU2).

PRECAUTIONARY/PREPAREDNESS ACTIONS...

REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE
FAVORABLE FOR SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH
AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR
THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS
AND POSSIBLE WARNINGS. SEVERE THUNDERSTORMS CAN AND OCCASIONALLY
DO PRODUCE TORNADOES.

&&

OTHER WATCH INFORMATION...CONTINUE...WW 349...WW 350...WW 351...

AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT
TO 1 INCH. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60 KNOTS.
A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. MEAN STORM MOTION
VECTOR 30035.


...HART

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 7, 6:37 PM EDT	Mesoscale Discussion	SPC	Banks, Bartow, Catoosa, Cherokee, Dade, Dawson and 16 more	53 min
Jul 7, 3:42 PM EDT	Mesoscale Discussion	SPC	Anson, Chatham, Cumberland, Durham, Edgecombe, Franklin and 20 more	63 min
Jul 7, 4:14 PM EDT	Severe Thunderstorm Watch	SPC	Anson, Beaufort, Bladen, Brunswick, Columbus, Craven and 27 more	7 hr
Jul 7, 7:24 PM EDT	Mesoscale Discussion	SPC	Anson, Beaufort, Bladen, Brunswick, Chatham, Columbus and 30 more	66 min

Nearby

Severe Thunderstorm Watches in North Carolina, 2016 Every severe thunderstorm watch in 2016

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.