MD 2012 CONCERNING SEVERE POTENTIAL…WATCH UNLIKELY FOR EASTERN MASSACHUSETTS
Mesoscale Discussion 2012
NWS Storm Prediction Center Norman OK
0823 AM CDT Fri Aug 18 2023
Areas affected…Eastern Massachusetts
Concerning…Severe potential…Watch unlikely
Valid 181323Z – 181430Z
Probability of Watch Issuance…5 percent
SUMMARY…Brief tornadoes will remain possible over the next hour as
a line of thunderstorms approaches the eastern Massachusetts coast.
DISCUSSION…Over the past 30-45 minutes, at least two tight,
low-level velocity couplets associated with possible tornadoes have
been observed from the KBOX radar as a line of thunderstorms
approaches the Boston area. VPW observations are sampling 0-1 km SRH
on the order of 500 m2/s2, which is very favorable for a continued
tornado threat assuming low-level thermodynamics remain favorable.
Based on observed and forecast soundings, temperatures in the low
70s are required to achieve adequate low-level buoyancy for
near-surface based convection capable of pose a tornado threat.
Latest surface observations show these conditions exist immediately
ahead of the line along a warm frontal zone draped from the Boston
area southward into Plymouth county. Consequently, additional brief
tornadoes will be possible before this line of storms reaches the
coast – especially on the northern end where a supercell-line hybrid
storm mode is noted. Given the very small spatial and temporal scale
of this threat, a watch is not expected.
..Moore/Grams.. 08/18/2023
…Please see www.spc.noaa.gov for graphic product…
ATTN…WFO…BOX…
LAT…LON 42397107 42467092 42457065 42367026 42157002 41957008
41787036 41717069 41647122 41717132 42067114 42277118
42397107
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