The National Weather Service (NWS) is still trying to confirm if tornadoes caused any of the storm damage that occurred in Northeast Iowa on Monday.

A complex line of strong to severe thunderstorms moved through the area during the early morning hours of June 22, 2015, and produced a combination of large hail, damaging wind, flooding, and likely a few tornadoes, NWS officials said. Wind damage, some of which was extreme, was most prevalent across northeast Iowa into southern Wisconsin.

According to NWS officials at the regional bureau in La Crosse, Wis., parts of Fayette and Clayton counties had more intense damage than other areas. Surveyors are looking at damage from Maynard to Arlington and around Garber for possible tornado activity. They are also studying damage between Eastman and Wauzeka in Crawford County, Wis., and from Cassville to Lancaster to north of Platteville in Grant County, Wis.

National Weather Service officials believe there could have been a few EF0 or EF1 tornadoes in the areas they are surveying. At the very least, they said damage indicates peak wind speeds may have exceeded 100 mph at times.

Officials said most of the damage relates to winds in the 60- to 80-mph range. Officials at the Dubuque Regional Airport measured a wind gust of 72 mph when the storms passed at 9:15 a.m. Earlier, when Monday's storms passed through Buchanan County, emergency management officials clocked 94 mph sustained winds at Independence High School.

NWS forecasters said it was an odd time of day for severe thunderstorms to occur, rolling across the region between 5 and 10 a.m.

In addition to the strong winds, flooding materialized after 2 to 5 inches of rain fell in a short period of time. A combination of flash flood and river flood warnings had been issued. A flood warning remains in effect for the Cedar River at Cedar Falls and Charles City.