MD 1130 CONCERNING SEVERE THUNDERSTORM WATCH 326… FOR WESTERN IA AND EASTERN NE
Mesoscale Discussion 1130
NWS Storm Prediction Center Norman OK
0448 PM CDT Sat Jun 17 2023
Areas affected...western IA and eastern NE
Concerning...Severe Thunderstorm Watch 326...
Valid 172148Z - 172345Z
The severe weather threat for Severe Thunderstorm Watch 326
continues.
SUMMARY...The severe-weather threat continues in WW326 across
western IA and eastern NE. Isolated damaging wind gusts and large
hail are possible as storms continue to develop and strengthen this
afternoon and evening.
DISCUSSION...Scattered thunderstorms have developed in the last
couple of hours across WW326 as a mid-level shortwave overspreads
the region. Diurnal heating, warm/moist advection, and steep lapse
rates currently support MLCAPE around 1000-1500 J/kg. Bulk shear has
been more limited, around 25 kts per current VAD profiles. However,
as the shortwave propagates east-northeastward, 30-40-kt mid-level
flow (currently observed at KOAX) will yield gradually strengthening
shear profiles. This should support stronger updraft cores with
convection developing and maturing in this area over the next couple
of hours. The main threats will be isolated damaging wind gusts up
to 70 mph and large hail up to around 1.5". The risk for these
hazards should peak in the next few hours before sunset and then
decrease relatively quickly thereafter as the shortwave overruns any
nocturnally diminishing surface instability.
..Flournoy.. 06/17/2023
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...DMX...FSD...OAX...
LAT...LON 41879640 42449650 42849610 43349565 43439504 43289440
42619401 41499403 40839420 40669470 40669540 41119611
41879640
