Mesoscale Discussion 2251
NWS Storm Prediction Center Norman OK
0326 PM CDT Fri Oct 13 2023
Areas affected…central Iowa
Concerning…Tornado Watch 710…
Valid 132026Z – 132200Z
The severe weather threat for Tornado Watch 710 continues.
SUMMARY…Low topped thunderstorms will remain capable of a couple
brief tornadoes and isolated small hail this afternoon.
DISCUSSION…Across WW710, low topped thunderstorms have gradually
deepened in an arc along a wind shift/frontal zone through the first
half of the afternoon. Ongoing within a weakly unstable environment
(MLCAPE 250-400 J/kg) updrafts have been slow to organize thus far.
However, with much of the buoyancy concentrated in the lowest 2 km,
low-level acceleration and dynamic pressure perturbations may still
favor some enhanced stretching potential as storms continue to
slowly deepen. Stretching of plentiful ambient vorticity along the
wind shift and beneath the upper low will support the risk for a
couple of brief tornadoes this afternoon. Small hail may also
accompany some of the more robust updrafts given the cold temps
aloft. While confidence in severe coverage is not high, the most
favored area for a couple of tornadoes appears to be across central
and southeastern portions of the watch area. Here, slightly deeper
moisture, along with some cloud breaks are supporting a local
maximum in low-level buoyancy (75-150 J/kg ML 3km CAPE). A few more
cellular elements and deeper updrafts have been noted suggesting
somewhat higher potential for a few funnel clouds and or brief
tornadoes this afternoon.
…Please see www.spc.noaa.gov for graphic product…
LAT…LON 40979127 40779133 40669146 40669186 40679213 40759250
40889280 41099298 41519347 41719375 42079446 42149457
42319479 42629489 42909480 43129454 42819318 42339226
41959184 41559152 41149129 40979127