Mesoscale Discussion 0143
NWS Storm Prediction Center Norman OK
0152 AM CST Tue Feb 07 2017
Areas affected...Much of Arkansas into southeast Missouri
Concerning...Severe Thunderstorm Watch 25...
Valid 070752Z - 070945Z
The severe weather threat for Severe Thunderstorm Watch 25
SUMMARY...A few storms will be capable of hail through early morning
across central and northern Arkansas into southeast Missouri.
DISCUSSION...Several small corridors of storms continue across much
of northern and central AR this morning, with the strongest cells
over far northern AR. Here, hail on the order of 0.75" to 1.00"
diameter appears likely as cells continue to train northeastward.
Cold air aloft with the midlevel thermal trough is helping to create
steep lapse rates, favorable for hail and strong updrafts. Storms
are currently situated on the northern fringe of the instability
pool to the south, comprised of 1000-1500 J/kg elevated MUCAPE. Lift
via warm advection/low-level jet is minimal, and forecast to shift
east of the area with time. Already, a batch of new showers and
storms has formed across western TN and KY, but remain disorganized
and not expected to post much of a hail threat. The best chance of
severe hail should remain over AR, where orographic lift may
continue to aid storms by helping a cool but moist boundary layer
reach the LFC. Veering winds in the lower-levels and backing aloft
with time may eventually lead to storm mode becoming a bit more
disorganized, but trends will continue to be monitored.
LAT...LON 34929162 34369299 34389351 34589389 34889390 36019327
37398991 37338949 37048899 36538878 36098889 35578935
35138986 35019023 34929162