SPC MD 449
[html]MD 0449 CONCERNING TORNADO WATCH 107... FOR INTERSTATE 40 CORRIDOR OF FAR EASTERN OKLAHOMA AND ARKANSAS
Mesoscale Discussion 0449
NWS Storm Prediction Center Norman OK
0537 PM CDT Mon Apr 11 2022
Areas affected...Interstate 40 corridor of far eastern Oklahoma and
Arkansas
Concerning...Tornado Watch 107...
Valid 112237Z - 120030Z
The severe weather threat for Tornado Watch 107 continues.
SUMMARY...An isolated supercell may persist for several more hours,
moving eastward near/north of the Interstate 40 corridor east of
Fort Smith into the Little Rock area through 7-9 PM. This will
continue to pose a risk for tornadoes, one or two possibly strong,
with some potential to begin to grow upscale with severe wind
beco*ing more prominent later this evening.
DISCUSSION...The axis of the primary mid-level short wave trough
appears to be progressing to the east of the region, and likely to
continue across and east of the Mississippi River into the lower
Ohio Valley through early evening. As this occurs, more prominent
mid-level height rises are forecast across the southeastern Great
Plains and Ozark Plateau, with the northern periphery of warmer and
more strongly capping elevated mixed-layer air shifting northward
toward the I-40 corridor through 00-02Z. This seems likely to
beco*e the primary focus for continuing stronger thunderstorm
development, aided by continuing forcing for ascent associated with
lower/mid tropospheric warm advection. The boundary-layer along
this corridor likely has reached peak late afternoon instability,
including CAPE on the order of 1500-2500+ J/kg.
Given this instability, modest clockwise curved low-level hodographs
and strong deep-layer shear, beneath 30-50 kt southerly to westerly
flow in the 850-500 mb layer will remain conducive to discrete
supercell development. The westerly co*ponent to the deeper layer
mean flow may be contributing to the the eastward propagation of the
one significant ongoing supercell now east of Fort Smith. It
appears that this could be maintained for several hours, coincident
with a near-surface thermal gradient associated with the remnants of
a previous outflow boundary, providing an environment favorable for
at least periodic, if not sustained, potential tornadic development.
..Kerr.. 04/11/2022
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...LZK...TSA...
LAT...LON 35619319 35549205 35309176 34929232 35019329 35199419
35449424 35619319
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Source: SPC MD 449 (http://ht**://www.spc.noaa.gov/products/md/md0449.html)