Alert archive / North Carolina / Mesoscale Discussions in 2020
Mesoscale Discussion 921
The Storm Prediction Center issued this mesoscale discussion at Jun 16, 2020, 2:36 PM EDT for 5 counties in North Carolina. It was in force for 2 hr.
The area
The outline as issued.
The facts
- Issued
- Jun 16, 2020, 2:36 PM EDT (18:36 UTC)
- Expired
- Jun 16, 2020, 5:00 PM EDT
- In force
- 2 hr
- Issued by
- the Storm Prediction Center
- Concerning
- Severe potential...watch unlikely
- Chance of a watch
- 20%
Counties Carteret County, NC, New Hanover County, NC, Onslow County, NC, Pamlico County, NC, Pender County, NC
The radar
The Morehead City radar (KMHX), 18 km from the middle of the area, began a volume at 18:38 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, 6.6 hours before the alert went out and 18 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.
- Mixed-layer CAPE
- 144 J/kg
- Mixed-layer CIN
- -58 J/kg
- Mixed-layer LCL
- 545 m above ground
- 0-6 km bulk shear
- 21 kt
- 0-1 km storm-relative helicity
- 112 m²/s²
- 0-3 km storm-relative helicity
- 151 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.3
The text
As transmitted.
295
ACUS11 KWNS 161837
SWOMCD
SPC MCD 161836
NCZ000-162100-
Mesoscale Discussion 0921
NWS Storm Prediction Center Norman OK
0136 PM CDT Tue Jun 16 2020
Areas affected...Portions of the Outer Banks and coastal NC
Concerning...Severe potential...Watch unlikely
Valid 161836Z - 162100Z
Probability of Watch Issuance...20 percent
SUMMARY...Storms moving onshore may pose an isolated strong/gusty
wind and perhaps brief tornado threat this afternoon. Watch issuance
appears unlikely at this time.
DISCUSSION...Low-topped convection off the coast of eastern NC has
recently begun to show signs of transient low-level rotation. This
activity is occurring in a modest low-level warm advection regime to
the north of a weak surface low. Seasonably cool temperatures aloft
and some ascent associated with a mid/upper low centered over SC are
also supporting these storms. Recent VWPs from KLTX and KMHX show a
veering/strengthening wind profile with height. However, flow in the
0-1 km AGL is still mostly from the east-northeast, which is
limiting inland destabilization. Still, as the surface low slowly
develops northward this afternoon, a more easterly component to the
near-surface winds should allow for at least weak destabilization
(MLCAPE generally 500-1500 J/kg) across parts of the Outer Banks and
coastal southeastern NC. This instability coupled with effective SRH
around 100-200 m2/s2 should continue to support occasional low-level
rotation with an isolated waterspout and strong/gusty winds
possible. As these storms move onshore, a brief tornado cannot be
ruled out along the immediate coast. Given the limited spatial
threat area and marginal overall environment for severe, watch
issuance appears unlikely at this time.
..Gleason/Goss.. 06/16/2020
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...MHX...ILM...
LAT...LON 33937822 34527807 34847763 35037704 35187661 35377605
35377555 35167544 34917593 34477645 34457706 34077763
33727781 33937822Nearby
Mesoscale Discussions in North Carolina, 2020Every mesoscale discussion in 2020
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.