SPC MD 1587



MD 1587 CONCERNING SEVERE POTENTIAL…WATCH UNLIKELY FOR PORTIONS OF NC/SC

MD 1587 Image

Mesoscale Discussion 1587
NWS Storm Prediction Center Norman OK
0528 PM CDT Tue Oct 16 2018

Areas affected...Portions of NC/SC

Concerning...Severe potential...Watch unlikely 

Valid 162228Z - 170100Z

Probability of Watch Issuance...5 percent

SUMMARY...Strong/gusty winds may occur on an isolated basis through
the evening. Watch issuance is unlikely.

DISCUSSION...Glancing influence of large-scale ascent associated
with an upper-level jet over the Mid-Atlantic/Northeast coupled with
modest low-level convergence along a stalled front should support
isolated to scattered convective development through the evening
across the southern half of NC and parts of SC. This generally
east-west oriented front will likely serve as a focus for
thunderstorms, with a couple attempts at convective initiation noted
recently near GSP in upstate SC. A meso-low noted on 22Z surface
analysis near FAY may also subtly enhance low-level convergence
along the front in southern NC.

Some cloud breaks to the south of the front have contributed to
temperatures in the low 80s at 2228Z. A moist-level airmass is also
present across the warm sector, with dewpoints generally in the
upper 60s to lower 70s. Daytime heating and plentiful moisture are
supporting MLCAPE around 250-1000 J/kg, with poor mid-level lapse
rates limiting even greater destabilization. 40-50+ kt of
west-southwesterly mid-level flow is present across much of the
Carolinas, and a strengthening wind profile with height is
contributing to around 40-50 kt of effective bulk shear. Mid-level
rotation within thunderstorm updrafts will likely occur given this
degree of shear, and a couple transient supercells cannot be ruled
out. A small line segment or thunderstorm cluster will probably
consolidate along the front as it moves eastward through the
evening.

Even with nocturnal cooling commencing soon, already steepened
low-level lapse rates should encourage efficient momentum transfer
of convective downdrafts to the surface. Isolated strong/gusty winds
primarily capable of tree damage appear to be the main severe
threat, but very isolated hail may also occur. Regardless, the
thermodynamic environment will remain quite marginal, and watch
issuance is unlikely at this time.

..Gleason/Edwards.. 10/16/2018

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

ATTN...WFO...MHX...RAH...ILM...CAE...GSP...

LAT...LON   34358191 34878185 35328123 35558022 35557834 35157592
            34857618 34577645 34587693 34367746 34007779 33817793
            33837819 33767854 33437895 34358191 

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