A TORNADO WATCH is in effect for southern and eastern Siouxland until 10 PM Monday night. The Sioux City Metro is not included in the watch but communities like Storm Lake, Spencer, Denison, and Tekamah should prepare for the possibility of a tornado this evening.
A line of strong and severe storms along a dry line, or steep difference in moisture, has already pushed through Siouxland. Siouxland’s Most Accurate has gotten reports of pea size hail blanketing Onawa, IA (pictured above, courtesy David & Amy Sick), and Holstein, IA. Winds of 50 to 60 mph were also reported with that storm that came through Holstein.
Penny size hail was reported in Sioux Rapids and Spencer, while bigger nickel size hail was reported in Spirit Lake.
Along with these severe thunderstorms, Siouxland is seeing non-severe gusty winds. The entire Siouxland area is under a Wind Advisory as winds gust to 50 mph without the presence of a severe storm. Tree damage was reported in Sac City from this strong wind.
While the severe threat will die down tonight, gusty winds will continue into tomorrow. The Wind Advisory will likely be extended.
Behind this front lies very dry air with relative humidity already plummeting below 20% in spots. The combination with the gusty winds has a Red Flag Warning in effect through the evening, and will likely be extended through tomorrow as well.