Alert archive / North Carolina / Mesoscale Discussions in 2017

Mesoscale Discussion 352

March 28, 201748 counties in North Carolina; 44 counties in Virginia

The Storm Prediction Center issued this mesoscale discussion at Mar 28, 2017, 1:58 PM EDT for 48 counties in North Carolina; 44 counties in Virginia. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued
Mar 28, 2017, 1:58 PM EDT (17:58 UTC)
Expired
Mar 28, 2017, 4:30 PM EDT
In force
3 hr
Issued by
the Storm Prediction Center
Chance of a watch
20%
All 92 counties

Alamance County, NC, Beaufort County, NC, Bertie County, NC, Camden County, NC, Carteret County, NC, Caswell County, NC, Chatham County, NC, Chowan County, NC, Craven County, NC, Cumberland County, NC, Currituck County, NC, Dare County, NC, Duplin County, NC, Durham County, NC, Edgecombe County, NC, Franklin County, NC, Gates County, NC, Granville County, NC, Greene County, NC, Halifax County, NC, Harnett County, NC, Hertford County, NC, Hoke County, NC, Hyde County, NC, Johnston County, NC, Jones County, NC, Lee County, NC, Lenoir County, NC, Martin County, NC, Moore County, NC, Nash County, NC, Northampton County, NC, Onslow County, NC, Orange County, NC, Pamlico County, NC, Pasquotank County, NC, Perquimans County, NC, Person County, NC, Pitt County, NC, Randolph County, NC, Sampson County, NC, Tyrrell County, NC, Vance County, NC, Wake County, NC, Warren County, NC, Washington County, NC, Wayne County, NC, Wilson County, NC, Amelia County, VA, Brunswick County, VA, Buckingham County, VA, Charles City County, VA, Charlotte County, VA, Chesterfield County, VA, City of Chesapeake, VA, City of Colonial Heights, VA, City of Emporia, VA, City of Franklin, VA, City of Hampton, VA, City of Hopewell, VA, City of Newport News, VA, City of Norfolk, VA, City of Petersburg, VA, City of Poquoson, VA, City of Portsmouth, VA, City of Richmond, VA, City of Suffolk, VA, City of Virginia Beach, VA, City of Williamsburg, VA, Cumberland County, VA, Dinwiddie County, VA, Gloucester County, VA, Goochland County, VA, Greensville County, VA, Halifax County, VA, Hanover County, VA, Henrico County, VA, Isle of Wight County, VA, James City County, VA, King and Queen County, VA, King William County, VA, Lunenburg County, VA, Mecklenburg County, VA, New Kent County, VA, Nottoway County, VA, Powhatan County, VA, Prince Edward County, VA, Prince George County, VA, Southampton County, VA, Surry County, VA, Sussex County, VA, York County, VA

The radar

The Norfolk radar (KAKQ), 101 km from the middle of the area, began a volume at 17:59 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, 6.0 hours before the alert went out and 165 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 12:00Z on 2017-03-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 87 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 12:00Z on 2017-03-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 113 square meters per square second.1939Sfc1 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
87 J/kg
Mixed-layer CIN
-180 J/kg
Mixed-layer LCL
951 m above ground
0-6 km bulk shear
24 kt
0-1 km storm-relative helicity
113 m²/s²
0-3 km storm-relative helicity
92 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

108 
ACUS11 KWNS 281759
SWOMCD
SPC MCD 281758 
NCZ000-VAZ000-282030-

Mesoscale Discussion 0352
NWS Storm Prediction Center Norman OK
1258 PM CDT Tue Mar 28 2017

Areas affected...Central and eastern Virginia and North Carolina

Concerning...Severe potential...Watch unlikely 

Valid 281758Z - 282030Z

Probability of Watch Issuance...20 percent

SUMMARY...Isolated strong to marginally severe storms capable of
hail are possible this afternoon mainly across southeast Virginia
into eastern North Carolina.

DISCUSSION...Surface heating beneath cool midlevel temperatures in
association with a shortwave trough has led to around 1000 J/kg
MUCAPE across central VA and NC. Visible satellite imagery shows
widespread cumulus development, with a few weak thunderstorms over
western VA aided by the higher terrain. Farther east, a relative
cool pockets was noted over eastern NC due to ongoing showers,
however, these will eventually move offshore with warmer air
returning from the west.

With time, further heating will erode any remaining CIN, allowing at
least isolated thunderstorms to form across the entire area. Little
focus exists given a broad/weak surface low, however, the best area
may be over southeastern VA and central to northeastern NC in a few
hours, as the instability axis shifts into that area, and where
low-level convergence will exist for a longer duration as winds
generally veer with time, from west to east. A cell or two could
exhibit supercell characteristics at times, but the main threat
should be hail as winds in the low-levels will be weak.

..Jewell/Guyer.. 03/28/2017

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

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

LAT...LON   36647933 37707851 37927762 37747683 37337623 36717582
            36147549 35477538 35127561 34657629 34387709 34947939
            35307990 35867980 36647933

Nearby

Mesoscale Discussions in North Carolina, 2017Mesoscale Discussions in Virginia, 2017Every mesoscale discussion in 2017

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.