MD 0308 CONCERNING TORNADO WATCH 60… FOR PARTS OF SOUTHWESTERN AND CENTRAL LOUISIANA INTO SOUTHWESTERN AND CENTRAL MISSISSIPPI
Mesoscale Discussion 0308
NWS Storm Prediction Center Norman OK
0943 AM CDT Tue Mar 22 2022
Areas affected...Parts of southwestern and central Louisiana into
southwestern and central Mississippi
Concerning...Tornado Watch 60...
Valid 221443Z - 221645Z
The severe weather threat for Tornado Watch 60 continues.
SUMMARY...A cluster of thunderstorms may continue to gradually
organize while spreading eastward across the region through midday,
perhaps increasingly preceded by isolated to widely scattered
supercell development. This will probably be accompanied by
increasing risk for damaging wind gusts and a few tornadoes, one or
two of which could become strong. Trends are being monitored for an
additional watch east of Tornado Watch 60.
DISCUSSION...Strongest convection has recently been focused along a
pre-frontal convective outflow boundary and the surface front,
particularly near where they intersect, across the Sabine River
vicinity north-northeastward toward Monroe. In advance of this
activity, warm layers in the lower/mid troposphere are still
contributing to weak inhibition, with seasonably moist
boundary-layer air confined to a narrowing plume across Louisiana
coastal areas through southwestern and central Mississippi. This is
roughly aligned with the strong south-southwesterly low-level jet
axis, including 40-50+ kt around 850 mb.
Through 16-18Z, latest model output suggests that an 850 mb speed
maximum will continue to nose inland along this corridor, associated
with an elongated secondary surface frontal wave. Coinciding with
continuing boundary-layer warming, large-scale forcing for ascent
downstream of the approaching mid-level trough, and associated
weakening of inhibition, substantive further convective
intensification and upscale growth seems probable.
Some further enlargement of the warm/moist sector, characterized by
mixed-layer CAPE on the order of 1500-2000 J/kg, is still possible
in association with the inland migrating jet streak, and it is
possible that discrete thunderstorms could begin forming and become
more prominent in advance of the convective system. If this occurs,
veering low-level wind profiles with height, exhibiting strong speed
shear and modest clockwise hodograph curvature, will be conducive to
supercells capable of producing tornadoes.
Supercell structures posing a risk for tornadoes may also evolve
within the developing convective system. Otherwise, with a large
component of the strong south-southwesterly deep-layer mean wind
fields oriented parallel to the convective system, eastward
progression will probably remain relatively slow. However, more
rapidly north-northeastward surging cells/segments within the
leading intense line probably will begin to pose increasing risk for
potentially damaging surface gusts through midday.
..Kerr.. 03/22/2022
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...JAN...LIX...LCH...SHV...
LAT...LON 29859343 30729279 31749175 32889089 33399010 33518969
33078895 31189000 29659176 29549290 29859343
