Alert archive / North Carolina / Mesoscale Discussions in 2011

Mesoscale Discussion 464

April 16, 20117 counties in North Carolina

The Storm Prediction Center issued this mesoscale discussion at Apr 16, 2011, 8:52 PM EDT for 7 counties in North Carolina. It was in force for 53 min.

The area

The outline as issued.

The facts

Issued
Apr 16, 2011, 8:52 PM EDT (00:52 UTC)
Expired
Apr 16, 2011, 9:45 PM EDT
In force
53 min
Issued by
the Storm Prediction Center

Counties Camden County, NC, Currituck County, NC, Dare County, NC, Hyde County, NC, Pamlico County, NC, Pasquotank County, NC, Tyrrell County, NC

The radar

The Morehead City radar (KMHX), 127 km from the middle of the area, began a volume at 00:54 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 00:00Z, 0.9 hours before the alert went out and 127 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, Newport, NC at 00:00Z on 2011-04-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2506 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, Newport, NC at 00:00Z on 2011-04-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 576 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
2506 J/kg
Mixed-layer CIN
-3 J/kg
Mixed-layer LCL
466 m above ground
0-6 km bulk shear
52 kt
0-1 km storm-relative helicity
576 m²/s²
0-3 km storm-relative helicity
688 m²/s²
Significant tornado parameter
9.2
Supercell composite
37.9

Open this sounding in Storm Lab

The text

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

414 
ACUS11 KWNS 170052
SWOMCD
SPC MCD 170052 
NCZ000-VAZ000-170145-

MESOSCALE DISCUSSION 0464
NWS STORM PREDICTION CENTER NORMAN OK
0752 PM CDT SAT APR 16 2011

AREAS AFFECTED...EXTREME ERN NC THROUGH EXTREME SERN VA

CONCERNING...TORNADO WATCH 150...

VALID 170052Z - 170145Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 150 CONTINUES.

THREAT FOR ISOLATED STRONG TORNADOES WILL PERSIST ACROSS EXTREME ERN
NC INCLUDING THE OUTER BANKS UNTIL ABOUT 03Z. SINCE THIS IS BEYOND
TORNADO WATCH 150 EXPIRATION TIME OF 01Z...PLANS ARE FOR WFO
MOREHEAD CITY AND WAKEFIELD TO LOCALLY EXTEND THE WATCH IN TIME.

BROKEN LINE OF STORMS INCLUDING A FEW DISCRETE SUPERCELLS CONTINUE
THROUGH EXTREME ERN NC FROM NEAR MOREHEAD CITY NWD TO NORFOLK.
ACTIVITY REMAINS EMBEDDED WITHIN AN ENVIRONMENT CHARACTERIZED BY
VERY LARGE HODOGRAPHS WITH 0-1 KM STORM RELATIVE HELICITY FROM
500-600 M2/S2 AND SUFFICIENT INSTABILITY FOR SURFACE BASED STORMS.
THREAT FOR LOW LEVEL MESOCYCLONES AND TORNADOES WILL PERSIST UNTIL
THE STORMS CLEAR THE OUTER BANKS.

..DIAL.. 04/17/2011

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

ATTN...WFO...AKQ...MHX...

LAT...LON   36677608 35727546 35207559 34917637 35027683 35957641
            36677608

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.