Mesoscale Discussion 1365 NWS Storm Prediction Center Norman OK 0734 AM CDT Sun Jun 28 2026 Areas affected...far southern Minnesota into northern and east-central Iowa Concerning...Severe Thunderstorm Watch 411... Valid 281234Z - 281430Z The severe weather threat for Severe Thunderstorm Watch 411 continues. SUMMARY...A line of storms will continue to produce strong to severe wind gusts over north-central Iowa, a portion of far south-central Minnesota, and perhaps into more of central/east-central Iowa later this morning. DISCUSSION...A long-lived MCS continues to move east across southern MN and northern IA, with the larger/stronger storms currently over north-central IA. This area is within the instability gradient, with access to a more favorable inflow air mass. While surface temperatures are currently cooler into eastern IA, the favorable southwesterly low-level jet should maintain theta-e advection this morning, fueling the MCS. A severe gust of 68 mph was measured earlier at Spencer, IA with the stronger southern part of the bow, and recent radar trends also indicate sporadic hail over 1.00" diameter is likely. Additional storm cores within the warm advection zone just south/east of the main bow have also increased recently, and brief hail may occur with that activity. Otherwise, the threat of severe wind gusts of 60 to 70 mph may gradually shift east/southeast over IA, as the southern flank favors the more unstable air mass along and west of the instability gradient. Storm gusts will also remain possible over far southern MN this morning, despite weaker instability as the system is quite organized. ..Jewell.. 06/28/2026 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...DVN...ARX...MPX...DMX...FSD... LAT...LON 44629430 44479362 43919273 43049210 42149175 41869199 41699247 41819336 42269390 42519446 42639495 42869507 43289445 43789414 44069412 44629430 MOST PROBABLE PEAK WIND GUST...55-70 MPH MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN
Source link