The Ames Tornado of 12 November 2005 : The Ames Tornado of 12 November 2005 “I thought we had a pretty good mascot. But when we showed up at Iowa State and they had a real tornado, that’s the real deal!” - CU Buffalo coach Gary Barnett
Slide3 : A very interesting event…. Unusually late in the year (but have had 23 tornadoes in November in past 54 years; majority in 2 outbreaks)
Slide4 : A very interesting event…. Unusually late in the year (but have had 23 tornadoes in November in past 54 years; majority in 2 outbreaks)
Almost the feared “worst case scenario” with 10,000s of fans arriving at stadium for ISU – Colorado football game
Slide5 : A very interesting event…. Unusually late in the year (but have had 23 tornadoes in November in past 54 years; majority in 2 outbreaks)
Almost the feared “worst case scenario” with 10,000s of fans arriving at stadium for ISU – Colorado football game
Missed the stadium by just over 3 miles (to NW), hitting roughly 50-60 minutes before kickoff
Slide6 : A very interesting event…. Unusually late in the year (but have had 23 tornadoes in November in past 54 years; majority in 2 outbreaks)
Almost the feared “worst case scenario” with 10,000s of fans arriving at stadium for ISU – Colorado football game
Missed the stadium by just over 3 miles (to NW), hitting roughly 50-60 minutes before kickoff
Well-forecasted (5 days of model runs indicating severe threat)
Slide7 : A very interesting event…. Unusually late in the year (but have had 23 tornadoes in November in past 54 years; majority in 2 outbreaks)
Almost the feared “worst case scenario” with 10,000s of fans arriving at stadium for ISU – Colorado football game
Missed the stadium by just over 3 miles (to NW), hitting roughly 50-60 minutes before kickoff
Well-forecasted (5 days of model runs indicating severe threat)
Emergency meeting of police, fire, ISU, hospital, and city officials at 9 am Saturday – indoor practice facility designated as triage site, mass casualties expected primarily from hail and lightning (tornado was considered a small risk)
Slide8 : A very interesting event…. Unusually late in the year (but have had 23 tornadoes in November in past 54 years; majority in 2 outbreaks)
Almost the feared “worst case scenario” with 10,000s of fans arriving at stadium for ISU – Colorado football game
Missed the stadium by just over 3 miles (to NW), hitting roughly 50-60 minutes before kickoff
Well-forecasted (5 days of model runs indicating severe threat)
Emergency meeting of police, fire, ISU, hospital, and city officials at 9 am Saturday – indoor practice facility designated as triage site, mass casualties expected primarily from hail and lightning (tornado was considered a small risk)
Planning for disaster about as good as could be expected, but many WHAT IFs.
Slide11 : Even with lots of moisture to mix down from above, the cap looks strong – substantial lift would be needed to remove the cap via cooling
Slide19 : 500 mb maps from the 2 other “big” November events showed a very similar pattern of a strong short wave swinging into W IA around the time of the tornado events – however, in those events, the tornadoes occurred in SE – EC Iowa November 9, 1975 November 15, 1988
Slide22 : In the other November events, the 850 mb low was further to the south, but general pattern was similar to the 2005 event
Slide25 : Surface low (approximated here by 925 mb low) and dew points in prior events also showed best conditions further southeast than 2005 event. Lifted Index and SRH maps (not shown) were typical of cold season tornado outbreaks – with very large SRH and only modest instability.
2005 event was noteworthy in how far NW tornado-favorable conditions developed, and how unstable conditions became (LIs of -6 or so versus -1 or -2 in prior events)
Saturday…. 4pm….2 hrs to kickoff : Saturday…. 4pm….2 hrs to kickoff SPC still talking mostly squall line
Tornado warnings in effect in W IA since 3:19 pm (watch since 2 pm) but with no reported touch downs
ISU in frequent communication with NWS-DMX
Based on storm upstream, ISU prepares to open gates to stadium 10 minutes early (4:20 instead of 4:30)
Slide29 : 22:24 22:32
Slide31 : Just before 4:30, the first tornadoes touched down – one near Boxholm in NW Boone county and another SW of Woodward in Dallas county
Woodward tornado seen via live web-cam from Madrid (15 miles SW of Ames)
Slide32 : Near Woodward, IA around 4:30 CST (R. Pfannkuch)
Slide34 : 22:41 22:49
Slide35 : At 4:45, tornado reported near Luther (8 miles SW of Ames). Unclear if ISU authorities knew this – but based on sudden wind shift, change in storm track, and call to NWS (expressing uncertainty in what would happen), officers begin evacuation at stadium, urging people to seek shelter in cars (for hail/lightning threat – scenario 1 in morning plan)
Slide37 : 22:58 23:06
Slide38 : At 4:50, based on tornado reports and knowledge of 53 mph movement, evacuations expanded and switched to scenario 2 at stadium (tornado threat) – CU players ordered off field, people told to go to concourses, restrooms, nearby buildings, ditches
Tornado touchdown near west edge of Ames at 5:00 near Lincoln Way
Slide46 : Initial touchdown in West Ames
Slide47 : Near N. Dakota crossing
Slide51 : Near Deer Run damage
Slide53 : Entrance to NorthRidge Heights – looking NW
Slide54 : View looking south along G.W.Carver toward Ames
Slide55 : Twin vortices
Slide57 : Apparent “weak” stage of tornado pulls large tree high into the air
Slide60 : Looking SSW between Gilbert & Ames
Slide61 : View looking N from Ames Country Club (between Ames & Gilbert)
Slide63 : View southward of widest part of path – just east of Gilbert (note new Middle School on right)
Summary : Summary November 12 2005 tornado event was classic cold season situation
Compared to prior IA November events, tornadic conditions extended further NW, and instability was greater
More evidence of enhanced risk when dry line reaches Iowa
Differential diabatic heating may have led to enhanced backing in C IA which contributed to tornadogenesis – importance of sfc boundaries and backed winds previously shown in many studies
What IF? : What IF? Tornado hitting stadium (track 3 miles SE) would also have hit Mary Greeley Hospital
Tornado would have hit stadium by 5:05 pm, 15 minutes after tornado evacuation began. Is that enough time?
People in concourses would likely have been blown right out, and restrooms were overcrowded
Metal roofing on nearby buildings would have likely caused serious problems to the thousands still outside
Stadium area not equipped for sheltering 50,000 people
Track only .5 – 1 mile NW would have destroyed most of town of Gilbert, hitting all 3 schools in the district
Acknowledgments : Acknowledgments Daryl Herzmann, John MacLaughlin – IEM/photos/helicopter surveys (thanks to those who took the photos and videos and contributed them, including ISU students)
Jim Bishop – www.stormgasm.com (video)