727
ACUS11 KWNS 272200
SWOMCD
SPC MCD 272159
NCZ000-VAZ000-272330-

Mesoscale Discussion 2127
NWS Storm Prediction Center Norman OK
0459 PM CDT Fri Sep 27 2024

Areas affected...Southern/central VA into extreme northern NC

Concerning...Tornado Watch 688...

Valid 272159Z - 272330Z

The severe weather threat for Tornado Watch 688 continues.

SUMMARY...Some tornado threat may persist into the evening. Some
parts of Tornado Watch 688 have been extended in time to expire at 8
PM EDT.

DISCUSSION...At 2155 UTC, two clusters of relatively low-topped
convection with embedded rotating cells are ongoing from extreme
northern NC into southern/central VA. One cluster is moving
northward to the east of Roanoke, near the leading edge of a
pronounced midlevel dry slot. The other cluster is moving across the
Tidewater region of Virginia, within a persistent low-level
warm-advection regime. Extensive cloudiness and poor lapse rates
have limited destabilization, but rich low-level moisture is
supporting MLCAPE of around 500 J/kg. Notable weakening of low-level
flow has been observed from both the KFCX and KAKQ radars, but 0-1
km SRH remains in the 150 m2/s2 range, sufficient to support some
tornado threat with any persistent low-topped supercells. Parts of
WW 688 have been extended in time to 8 PM EDT in order to address
the remaining threat.

..Dean.. 09/27/2024

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

ATTN...WFO...AKQ...LWX...RNK...

LAT...LON   36717991 37047998 37678006 37897946 37777828 37727676
            37567606 36827603 36417607 36117640 36087704 36697706
            36627868 36527935 36567977 36717991