Mesoscale Discussion 490

Issued

May 3, 2021, 12:35 PM EDT (16:35 UTC)

Expired

May 3, 2021, 2:30 PM EDT

In force

115 min

Issued by

the Storm Prediction Center

Concerning

Severe potential...watch possible

Chance of a watch

40%

The Raleigh/Durham radar (KRAX), 96 km from the middle of the area, began a volume at 16:37 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.

792 
ACUS11 KWNS 031635
SWOMCD
SPC MCD 031635 
NCZ000-SCZ000-031830-

Mesoscale Discussion 0490
NWS Storm Prediction Center Norman OK
1135 AM CDT Mon May 03 2021

Areas affected...Southeast North Carolina

Concerning...Severe potential...Watch possible 

Valid 031635Z - 031830Z

Probability of Watch Issuance...40 percent

SUMMARY...A developing line of storms may pose a damaging wind
threat over the next few hours, and a watch is possible if
intensification continues.

DISCUSSION...Surface observations across central NC show a residual
cold front in place from Raleigh, NC southward into northeast SC.
Satellite and radar trends show thunderstorms developing along this
boundary across southeast NC. Mostly clear skies ahead of this line
have allowed for temperatures to warm into the low 80s amid rich
boundary-layer moisture (dewpoints in the upper 60s and low 70s
noted). This is supporting around 2000 J/kg MLCAPE across much of
eastern NC. Sufficient deep-layer shear for organized convection is
noted with 30-35 knots of effective bulk shear over the region.
Low-level shear is somewhat lacking as local VWPs show a nearly
uni-directional wind profile in the lowest 3 km and only 20 knots of
0-3 km bulk shear. However, steep low-level lapse rates approaching
8 C/km will support efficient downward mixing and the potential for
damaging wind gusts. While winds are the primary concern, a few
instances of severe hail are possible given adequate deep-layer
shear and orthogonal mean flow off the boundary (which may support a
few discrete to semi-discrete storms). Discrete convection ahead of
this line within the warm sector may also pose a wind/hail threat.
Trends will be monitored, and a watch is possible if intensification
becomes apparent.

..Moore/Grams.. 05/03/2021

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

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

LAT...LON   34547932 34937905 35247886 35607893 35967864 36027792
            35987716 35557646 35077595 34527611 34007679 33927764
            33887809 34117885 34547932

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

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.