Mesoscale Discussion 0136
NWS Storm Prediction Center Norman OK
0639 PM CST Mon Mar 02 2020
Areas affected...Parts of south central and southeast Missouri
...adjacent northern Arkansas...into southern Illinois...western
Kentucky and adjacent southwestern Indiana
Concerning...Tornado Watch 35...
Valid 030039Z - 030215Z
The severe weather threat for Tornado Watch 35 continues.
SUMMARY...Strong to severe storms, including isolated supercells,
will continue to overspread southeast Missouri into nearby portions
of the lower Ohio Valley through 8-10 PM CST, posing a risk for
severe hail and perhaps a tornado or two.
DISCUSSION...Thunderstorm development, generally discrete, has
gradually increased across south central and southeast Missouri into
the vicinity of the confluence of the Ohio and Mississippi Rivers.
This has generally been focused near through north of a frontal
zone, downstream of a a modest low now to the east-northeast of
Harrison AR, supported by low-level convergence along the front and
lower/mid tropospheric warm advection.
Through 02-04Z, the surface low is forecast to migrate toward the
Poplar Bluff vicinity, with the trailing cold front advancing
southeastward through northwest Arkansas. While new thunderstorm
development does not appear entirely out of the question along/ahead
of the cold front, upper support near and south of the zonal to
broadly anticyclonic high-level jet axis extending across the Ozark
Plateau into Tennessee Valley remains unclear. Models generally
indicate an area of enhanced upper divergence developing
across southeast Missouri into the lower Ohio valley this evening
near/north of the jet axis, which may enhance ongoing convection as
it spreads eastward within 30-40 kt lower/mid tropospheric mean
flow. This may include strengthening of southwesterly flow around
850 mb, and at least some enlargement of low-level hodographs.
While ongoing storms may eventually congeal into a convective
cluster, it is not obvious that this will be rapid or soon. And as
long as activity remains discrete in nature, stronger cells probably
will continue to pose a risk for severe hail, and perhaps a tornado
or two mainly across far southeast Missouri and the Missouri
Bootheel region into adjacent portions of southern Illinois and
...Please see www.spc.noaa.gov for graphic product...
LAT...LON 37299223 37769091 37968933 38118768 37308758 36618894
36459025 36359282 37299223