Alert archive / North Carolina / Mesoscale Discussions in 2021

Mesoscale Discussion 100

February 16, 20215 counties in North Carolina

The Storm Prediction Center issued this mesoscale discussion at Feb 16, 2021, 12:11 AM EST for 5 counties in North Carolina. It was in force for 64 min.

The area

The outline as issued.

The facts

Issued
Feb 16, 2021, 12:11 AM EST (05:11 UTC)
Expired
Feb 16, 2021, 1:15 AM EST
In force
64 min
Issued by
the Storm Prediction Center
Concerning
Severe potential...watch possible
Chance of a watch
60%

Counties Carteret County, NC, Dare County, NC, Hyde County, NC, Onslow County, NC, Pamlico County, NC

The radar

The Morehead City radar (KMHX), 29 km from the middle of the area, began a volume at 05:15 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 watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

The nearest sounding before it

Newport, NC (KMHX), launched 00:00Z, 5.2 hours before the alert went out and 29 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 2021-02-16Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 2021-02-16The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 241 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
456 m above ground
0-6 km bulk shear
62 kt
0-1 km storm-relative helicity
241 m²/s²
0-3 km storm-relative helicity
300 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

145 
ACUS11 KWNS 160512
SWOMCD
SPC MCD 160511 
NCZ000-160615-

Mesoscale Discussion 0100
NWS Storm Prediction Center Norman OK
1111 PM CST Mon Feb 15 2021

Areas affected...North Carolina coastal areas

Concerning...Severe potential...Watch possible 

Valid 160511Z - 160615Z

Probability of Watch Issuance...60 percent

SUMMARY...Isolated supercells with the potential to produce
tornadoes and/or damaging wind gusts could increase further as a
line of thunderstorms rapidly spreads into the Outer and Inner Banks
area of North Carolina through 1-3 AM EST.

DISCUSSION...Embedded within 50-60 kt southwesterly deep-layer mean
ambient flow, a broken line of thunderstorms continues to rapidly
move northeastward into/through the southern Mid Atlantic coast
region.  Near the intersection of this line and a surface warm
frontal zone, one embedded cell recently intensified rapidly,
including the development of a strong low-level mesocyclone. 
However, this is occurring to the cool side of the front, and
appears rooted above a sharp, albeit shallow, surface-based stable
layer.

Based in surface analysis the past few hours, there has been at
least some inland advancement of the frontal zone, and weak
boundary-layer based destabilization appears possible into coastal
areas northeast of Morehead City, ahead of the line during the next
few hours.  As this occurs, probabilities for a couple of tornadoes
and/or damaging wind gusts would seem likely to increase, in the
presence of large clockwise-curved low-level hodographs.

..Kerr/Guyer.. 02/16/2021

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...MHX...ILM...

LAT...LON   34607785 35447630 35617582 35697539 35487525 34947553
            34407659 33987751 34117778 34607785

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Feb 16, 12:41 AM ESTTornado WatchSPCBeaufort, Carteret, Craven, Dare, Duplin, Hyde and 6 more3 hr

Nearby

Mesoscale Discussions in North Carolina, 2021Every mesoscale discussion in 2021

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.