MD 1647 CONCERNING SEVERE POTENTIAL…WATCH POSSIBLE FOR MUCH OF SOUTH CENTRAL AND SOUTHEASTERN MISSOURI INTO NORTHEASTERN ARKANSAS…AND PARTS OF ADJACENT SOUTHERN ILLINOIS AND WESTERN KENTUCKY/TENNESSEE
Mesoscale Discussion 1647
NWS Storm Prediction Center Norman OK
0245 AM CDT Thu Aug 04 2022
Areas affected...much of south central and southeastern Missouri
into northeastern Arkansas...and parts of adjacent southern Illinois
and western Kentucky/Tennessee
Concerning...Severe potential...Watch possible
Valid 040745Z - 041015Z
Probability of Watch Issuance...40 percent
SUMMARY...The risk for strong to occasionally severe wind gusts may
increase during the next few hours, as a cluster of vigorous
thunderstorms continues to organize and maintain strength while
propagating southward across the region through daybreak. It is not
yet clear that a severe weather watch will be needed, but trends are
being monitored for this possibility.
DISCUSSION...Perhaps aided by strengthening large-scale ascent,
convection has been intensifying within a corridor of strengthening
low-level warm advection and frontogenetic forcing. Recently, cloud
tops have been cooling along with increasing peak lightning flash
rates, north of Cape Girardeau into the Fort Leonard Wood vicinity.
There have been several notable and persistent lower/mid-level
mesoscale cyclonic circulations evident within this activity, which
might strengthen further during the next few hours as vigorous
convection is likely maintained by inflow of seasonably moist air
characterized by sizable CAPE on the order of 1500-3000 J/kg.
Although northwesterly to northerly deep-layer mean flow and shear
are generally weak to modest respectively, strengthening rear inflow
associated with the developing mesoscale circulations may contribute
to increasing potential for strong surface gusts, aided by heavy
precipitation loading and downward momentum transfer. The
organizing convective system may persist into at least the 12-13Z
time frame, southward through much of northeastern Arkansas and the
Missouri Bootheel vicinity, before beginning to weaken.
..Kerr/Thompson.. 08/04/2022
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...PAH...MEG...LSX...LZK...SGF...
LAT...LON 37259181 37199094 37328947 36108961 35859233 37139306
37259181
