The Storm Prediction Center in Norman, Oklahoma on April 14th, 2012 posted a rare High Risk of Severe Weather for much of Western Iowa, with a moderate and slight risk nearby. Tornadoes, 3″ hail, Damaging Winds in excess of 70 MPH, were all forecasted for the day on April 14th. A warm level jet, dew points in the 60’s, and low-level winds could easily whip up tornadoes at any time. And it did just that.

By 4PM on the 14th, severe thunderstorm warnings began coming in like flies across Southwestern Iowa; including two tornado warnings. At 5PM, the Storm Prediction Center went ahead and issued Tornado Watch #169 until Midnight, keeping consistent with its probabilities:  Violent tornadoes, Hail up to 3″ in diameter, Damaging Winds in Excess of 70 MPH, and Dangerous lightning. Warnings continued to come in quickly. Tornado Warnings were seen at least once an hour. The SPC was nearly pinpoint on their forecast: 2.5″ hail reports, 70 MPH wind gusts, and yes… tornadoes.

At 5:24PM… the National Weather Service in Omaha/Valley, Nebraska issued a Tornado Warning for West Central Fremont and Northeastern Otoe NE counties due to radar indicating strong rotation around the area. The cities of Sidney and Thurman were affected. Ten minutes later… the Tornado Warning for Northeastern Otoe NE county was canceled. The city of Thurman was the only city left in the warning. At 5:35pm…the following report came in over the NWS Chatrooms: OAX: Thurman [Fremont Co, Iowa] emergency mnger reports TORNADO — 75 percent of the town of thurman was destroyed. the town has been evacuated with an emergency shelter in a nearby town. no power in the town. no major injuries. Clearly, Thurman was nearly gone. A assessment team was dispatched to go to that area and have a summary available later the next morning.

A few hours later, at 7:11pm, the National Weather Service in Des Moines issued a Tornado Warning for Southern Madison and Northeastern Union counties for doppler radar indicated rotation. Again, with this system, no storm reports of damage were reported until much later. By 7:30pm… reports were received that areas Northwest of Creston, including its hospital, were a total devastation. Patients were being transported to other medical centers, and fortunately none were hurt.

Much, much later, at 12:55am, the National Weather Service again in Omaha/Valley issued a Tornado Warning for Pottawattamie county until 1:30am. Four minutes later, local law enforcement confirmed the warning saying that a large tornado was on the ground near McClelland, or 21 miles East of Omaha, moving Northeast at 40 mph. Law enforcement and Radar continued to report the tornado until 1:12am, when it was canceled due to rotation moving out of the warned area. Damage was reported around the area and assessment teams were dispatched to go to this area later the next morning.

Assessments from the next day later revealed that the Creston and Thurman tornadoes were “strong” EF-2’s, while the McClelland tornado was an EF-1. The Thurman tornado spanned a length of 10 miles while the Creston tornado was  14 miles. The Creston tornado destroyed the Creston Medical Clinic, Southwestern Community College, the Green Hills Educational Center, and many farmsteads Northwest of Creston. The Thurman tornado did more further damage, with a few minor injuries, however hospitalization were required for the drivers of the 4 rigs that got blown over. The most serious injury was someone with a punctured lung.

More information on the CRESTON tornado: http://www.crh.noaa.gov/images/dmx/StormSurveys/2012/2012-04-14_Creston_Writeup.pdf

More information on the THURMAN and MCCLELLAND tornadoes: http://www.crh.noaa.gov/news/display_cmsstory.php?wfo=oax&storyid=81903&source=2