STORM TRACK: January 31, 1987 (Volume 10 Issue 2)

A supercell thunderstorm passed through eastern Iowa on September 28, 1986, a Sunday afternoon. We were blessed with a southwesterly upper air flow, so we were in heaven for a while here in Iowa. This particular day, we had an unusually unstable air mass. In fact, the air mass had been unstable for several days leading up to the 28th. On Friday, September 26th, a small gustnado hit Mt. Vernon, IA about 4 am. Winds 80 mph or better broke window glass and downed signs. Later that day, a few small tornadoes moved across North Central Iowa.

On September 28th, a line of thunderstorms formed right over Cedar Rapids around 1:30 pm and tracked northeastward. When they reached northern Illinois and southeast Wisconsin, the storms dumped heavy rains, hail, and a few tornadoes. After the storms passed, East Iowa cleared, the sun came out, and we went back to ambient flow. A cold front was still located in Northern and Western Iowa, so I figured we would get more thunderstorms. In fact, the NSSFC in Kansas City had boxed all or part of the frontal zone over the state.

About 5 pm, a lone thunderstorm popped up on its own well ahead of the surface front just east-northeast of Des Moines, The storm continued to grow and grow, as there were no other storms in the area to share the available energy and moisture. Around 5:30 pm, large hail was reported northwest of Colfax, IA accompanied by strong gust winds. The Des Moines Weather Service was right on top of the storm and I got a phone call at the radio station just after a severe thunderstorm warning was issued. The storm was about 90 miles west- southwest of where I was in Cedar Rapids, and already the cirrus anvil was over my head moving northeastward. Looking toward the southwest horizon, I could see the sharp southern back edge of the thunderstorm. I thought this would be a good storm to chase but I'm the person who has to relay severe weather information to our spotters and radio listeners, so I sat in my office and drooled on the radar screen.

The storm produced 3 maybe 4 tornadoes with a total path length of 55 miles. One of the tornadoes was near Baxter, IA in northern Jasper County and was photographed on a VCR by a state trooper. The tornado was a large cone with multiple vortices moving rapidly through corn fields and crossing a road before going into the rope stage. Some people said the tornado was visible for 45 minutes lasting from 5:45 to about 6:30 pm. In southern Tama county, listeners called me to say there were 4 funnels dangling from a low cloud south of Tama and then formed one big tornado (multi-vortex for sure). Path width was about 1/2 mile. The storm collapsed about 8 pm and dropped golfball- size hail. By the time the storm hit us in Cedar Rapids, it was down to levels 1 and 2 on radar. Boooo.

The storm was impressive on the GOES satellite, but was more impressive on radar. There was a V-notch hook for almost an hour, from 6 to 7 pm, as the storm moved across northern Jasper County. It was a great storm; the best of the season for Eastern Iowa. Later that evening, another tornado hit Colwell, IA about 40 miles north of Waterloo.

The following is a listing of severe weather reports from the Des Moines weather service for September 28, 1986.

Time (CDT) Event

5:35 pm Tree and structural damage reported in NE Polk Co. A barn and corn crib were damaged near Bondurant.

5:41 pm A tornado was reported on the ground NE of Mingo in NE Jasper Co (about 20 miles northeast of Des Moines).

5:49 pm Polk County sheriff reports a tornado in extreme SW Marshall Co.

5:58 pm Tornado west of Baxter in Jasper Co.

6:20 pm Tornado is 5 miles north of Newton near Hwy. 14.. The storm was moving east at 35 mph.

6:53 pm Tornado is 6 miles south of Tama near Hwy 63 in Tama Co.

7:03 pm Funnel clouds reported at Royal, just west of Spencer in Clay Co.

7:05 pm Tornado damaged a farm building 1 mile east and south of Everly in Clay Co.

7:10 pm Police report funnel south of Fort Dodge in Webster Ca.

You folks in the south should remember that when the Texas chase season is over in late Map, Iowa's season is just getting started. If anyone is planning to chase is Iowa, please listen to me on WMT-AM radio 600 for updated weather information. When severe weather is in the area, we go to an ALL WEATHER format.