Alert archive / North Carolina / Mesoscale Discussions in 2014

Mesoscale Discussion 1921

November 17, 201423 counties in North Carolina

The Storm Prediction Center issued this mesoscale discussion at Nov 17, 2014, 1:19 PM EST for 23 counties in North Carolina. It was in force for 116 min.

The area

The outline as issued.

The facts

Issued: Nov 17, 2014, 1:19 PM EST (18:19 UTC)
Expired: Nov 17, 2014, 3:15 PM EST
In force: 116 min
Issued by: the Storm Prediction Center

All 23 counties

Beaufort County, NC, Bertie County, NC, Camden County, NC, Carteret County, NC, Chowan County, NC, Craven County, NC, Currituck County, NC, Dare County, NC, Duplin County, NC, Greene County, NC, Hyde County, NC, Jones County, NC, Lenoir County, NC, Martin County, NC, New Hanover County, NC, Onslow County, NC, Pamlico County, NC, Pasquotank County, NC, Pender County, NC, Perquimans County, NC, Pitt County, NC, Tyrrell County, NC, Washington County, NC

The radar

The Morehead City radar (KMHX), 71 km from the middle of the area, began a volume at 18:20 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 12:00Z, 6.3 hours before the alert went out and 71 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 849 m above ground
0-6 km bulk shear: 57 kt
0-1 km storm-relative helicity: 227 m²/s²
0-3 km storm-relative helicity: 256 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.

405 
ACUS11 KWNS 171820
SWOMCD
SPC MCD 171819 
NCZ000-VAZ000-172015-

MESOSCALE DISCUSSION 1921
NWS STORM PREDICTION CENTER NORMAN OK
1219 PM CST MON NOV 17 2014

AREAS AFFECTED...PORTIONS OF ERN NC

CONCERNING...TORNADO WATCH 554...

VALID 171819Z - 172015Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 554 CONTINUES.

SUMMARY...SHOWERS AND THUNDERSTORMS WILL CONTINUE TO DEVELOP ACROSS
THE WATCH AREA THIS AFTERNOON. THE THREAT FOR A FEW
TORNADOES/LOCALLY DAMAGING WIND GUSTS WILL CONTINUE.

DISCUSSION...RADAR AND SATELLITE IMAGERY INDICATE A CONFLUENCE LINE
CONTINUES TO EXTEND SOUTH OFF THE COAST OF NC...GENERALLY FROM
ONSLOW AND CARTERET COUNTIES TO THE SOUTH. THIS LINE IS ENHANCING
THUNDERSTORM ACTIVITY ALONG IT...WITH CELLS REMAINING IN RELATIVELY
DISCRETE MODES. HOWEVER...AS THE TRAJECTORY OF THIS ACTIVITY WILL
KEEP MOST OF IT OFFSHORE...ANY LARGER THREAT WILL MOST LIKELY BE THE
RESULT OF ENHANCED ASCENT AND RESULTANT THUNDERSTORM ACTIVITY FROM A
SFC WAVE APPROACHING FROM THE WEST. 

MOST RECENT MESOANALYSIS INDICATES BEST SFC-BASED BUOYANCY REMAINS
OFFSHORE...BUT VALUES OF AROUND 500-1000 J/KG NOW EXIST ACROSS ERN
NC. WITH THE STRONG LOW-LEVEL AND DEEP-LAYER WIND FIELDS PRESENT ON
THE PERIPHERY OF THE MID-LEVEL JET MAXIMA TO THE WEST...AND THE
CONTINUED INFLUX OF MOIST AIR OFF THE ATLANTIC...ANY ENHANCEMENT IN
THUNDERSTORM ACTIVITY WILL RESULT IN AN INCREASED THREAT FOR LOCALLY
DAMAGING WINDS AND A FEW TORNADOES.

..PICCA/CORFIDI.. 11/17/2014

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

ATTN...WFO...AKQ...MHX...RAH...ILM...

LAT...LON   35657793 36947544 35067544 33777794 35657793

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Nov 17, 9:56 AM EST	Mesoscale Discussion	SPC	Beaufort, Bladen, Brunswick, Carteret, Chowan, Columbus and 19 more	2 hr
Nov 17, 10:26 AM EST	Tornado Watch	SPC	Beaufort, Bertie, Brunswick, Camden, Carteret, Chowan and 20 more	7 hr

Nearby

Mesoscale Discussions in North Carolina, 2014 Every mesoscale discussion in 2014

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.