Chicago-Mackinac Race ____________________________________________________________________________ Mark A. Thornton © 2012 The 2011 Chicago to Mackinac Race 1 of 65

Chicago-Mackinac Race ____________________________________________________________________________ Mark A. Thornton © 2012 Sponsored by the Chicago Yacht Club. Chicago, Illinois to Mackinac Island, Michigan, a distance of approximately 300 nautical miles. The 2011 race marked the 103 rd time the race had taken place. In 2011, nearly 350 boats participated with approximately 3,500 crew members. The cruising sailboats started on Friday afternoon (7/15) while the rest of the competitors started on Saturday morning (7/16). Most traditional sailboats finish in 30 to 70 hours. The record of 23 hours, 30 minutes was set in A Long Tradition 2 of 65

Chicago-Mackinac Race ____________________________________________________________________________ Mark A. Thornton © 2012 The Fleet Encountered A Strong Storm System On Sunday Night Many boats were forced to withdraw from the race due to damage to sails and rigging. And tragically, Suzanne Bickel and Mark Morley perished near the Fox Islands during the capsize of WingNuts -- the first weather-related fatalities in the races history. 3 of 65

Chicago-Mackinac Race ____________________________________________________________________________ Mark A. Thornton © 2012 The Chicago-Mac Storms A Meteorological Analysis 4 of 65

Chicago-Mackinac Race ____________________________________________________________________________ Mark A. Thornton © 2012 The Forecast: Friday, July 15 The SPC Day Three Convective Outlook mentions that a storm complex could backbuild or develop east southeast into parts of northern Minnesota, northern Wisconsin and upper and northern lower Michigan on Sunday afternoon. The potential for thunderstorms was mentioned before the start of the race at the Friday night weather briefing. 5 of 65

Chicago-Mackinac Race ____________________________________________________________________________ Mark A. Thornton © 2012 The Forecast: Saturday, July 16 Saturday, July 16 – The SPC Day Two Outlook continued to focus on the upper Great Lakes as a likely area for the development of severe weather from late Sunday into early Monday morning. NWS Gaylord issued a Hazardous Weather Outlook at 4:38 EDT on Saturday, July 15 which mentioned the possibility of strong and potentially damaging thunderstorms Sunday night and Monday. The HWO stated any storms that do develop Sunday night and Monday may contain damaging winds. 6 of 65

Chicago-Mackinac Race ____________________________________________________________________________ Mark A. Thornton © 2012 The Initial Forecast – Sunday, July 17 Hail Wind Tornado Overall 7 of 65

Chicago-Mackinac Race ____________________________________________________________________________ Mark A. Thornton © 2012 At 1630Z – The SPC upgraded the potential for severe thunderstorms and damaging wind gusts across the upper Great Lakes The Forecast Gets Upgraded – 1630Z 8 of 65

Chicago-Mackinac Race ____________________________________________________________________________ Mark A. Thornton © 2012 Sunday, July 17, 2011 A Very Supportive Environment For Thunderstorms 9 of 65

Chicago-Mackinac Race ____________________________________________________________________________ Mark A. Thornton © 2012 Extremely High Surface Dew Points – 21Z 10 of 65

Chicago-Mackinac Race ____________________________________________________________________________ Mark A. Thornton © 2012 Rhinelander, WI Observations 89 F 79 F 11 of 65

Chicago-Mackinac Race ____________________________________________________________________________ Mark A. Thornton © 2012 ML CAPE – 21Z 12 of 65

Chicago-Mackinac Race ____________________________________________________________________________ Mark A. Thornton © 2012 Synoptic Scale Lift July 21ZJuly 0Z 13 of 65

Chicago-Mackinac Race ____________________________________________________________________________ Mark A. Thornton © 2012 Mesoscale Lift Visible Satellite 1902Z Visible Satellite 2045Z 14 of 65

Chicago-Mackinac Race ____________________________________________________________________________ Mark A. Thornton © 2012 Wind Shear – 21Z 15 of 65

Chicago-Mackinac Race ____________________________________________________________________________ Mark A. Thornton © 2012 Mid-Level Support – 21Z 16 of 65

Chicago-Mackinac Race ____________________________________________________________________________ Mark A. Thornton © mb Divergence – 21Z 17 of 65

Chicago-Mackinac Race ____________________________________________________________________________ Mark A. Thornton © of 65

Chicago-Mackinac Race ____________________________________________________________________________ Mark A. Thornton © 2012 Thunderstorm Initiation 19 of 65

Chicago-Mackinac Race ____________________________________________________________________________ Mark A. Thornton © 2012 Thunderstorm Initiation Storms formed in two areas: Southeast of Duluth, Minnesota near the warm front and lake breeze boundaries. Near Marquette, Michigan in association with lake breeze fronts. The systems later merged near Lake Michigan before crossing the lake. 20 of 65

Chicago-Mackinac Race ____________________________________________________________________________ Mark A. Thornton © 2012 Thunderstorms Develop In Wisconsin 21 of 65

Chicago-Mackinac Race ____________________________________________________________________________ Mark A. Thornton © 2012 KDLH 2117Z KDLH 2153Z Initial Development: 2117Z to 2153Z 22 of 65

Chicago-Mackinac Race ____________________________________________________________________________ Mark A. Thornton © 2012 KDLH 2153Z KDLH 2255Z A Period of Explosive Development – 2153Z to 2255Z 23 of 65

Chicago-Mackinac Race ____________________________________________________________________________ Mark A. Thornton © 2012 The Linear Structure Expands: 2255Z to 0008Z KDLH 2255Z KDLH 0008Z 24 of 65

Chicago-Mackinac Race ____________________________________________________________________________ Mark A. Thornton © 2012 KGRB 0006ZKGRB 0122Z The System Shifts In Response to the Steering Winds: 0006Z to 0122Z KGRB Animation 0006Z to 0122Z 25 of 65

Chicago-Mackinac Race ____________________________________________________________________________ Mark A. Thornton © 2012 Thunderstorms Develop In Michigans Upper Peninsula 26 of 65

Chicago-Mackinac Race ____________________________________________________________________________ Mark A. Thornton © 2012 KMQT 2242Z Initial Development Along The Lake Breeze Front 27 of 65

Chicago-Mackinac Race ____________________________________________________________________________ Mark A. Thornton © 2012 KMQT 2242ZKMQT 2356Z Expansion of Thunderstorms Across the Upper Peninsula: 2242Z to 2356Z 28 of 65

Chicago-Mackinac Race ____________________________________________________________________________ Mark A. Thornton © 2012 KMQT 0000ZKMQT 0201Z Expansion of Thunderstorms Across the Upper Peninsula: 0000Z to 0201Z 29 of 65

Chicago-Mackinac Race ____________________________________________________________________________ Mark A. Thornton © 2012 KMQT 0201ZKMQT 0302Z The Systems Expand, Consolidate and Move East: 0201Z to 0302Z 30 of 65

Chicago-Mackinac Race ____________________________________________________________________________ Mark A. Thornton © 2012 Thunderstorms Reach Lake Michigan 31 of 65

Chicago-Mackinac Race ____________________________________________________________________________ Mark A. Thornton © 2012 A History Of Strong Winds KAPX 0301Z SPC High Wind Reports <= 0300Z 32 of 65

Chicago-Mackinac Race ____________________________________________________________________________ Mark A. Thornton © 2012 KAPX (Gaylord, MI) issued a Marine Weather 0247Z These storms will likely produce strong gusty winds of 30 knots or higher…and could pose a serious hazard for boaters … Boaters should consider heading for shore before the storms arrive. KGRB (Green Bay, WI) issued at Marine Weather 0248Z Mariners can expect dangerous winds in excess of 50 knots…high waves…dangerous lightning…and heavy rains. Boaters should seek safe harbor immediately. Marine Alerts Are Issued 33 of 65

Chicago-Mackinac Race ____________________________________________________________________________ Mark A. Thornton © 2012 The Storms Cross The Lake 34 of 65

Chicago-Mackinac Race ____________________________________________________________________________ Mark A. Thornton © 2012 KAPX 0301Z 16.5 kts 60 18, , of 65

Chicago-Mackinac Race ____________________________________________________________________________ Mark A. Thornton © 2012 KAPX 0306Z 36 of 65

Chicago-Mackinac Race ____________________________________________________________________________ Mark A. Thornton © 2012 KAPX 0310Z 37 of 65

Chicago-Mackinac Race ____________________________________________________________________________ Mark A. Thornton © 2012 KAPX 0315Z 38 of 65

Chicago-Mackinac Race ____________________________________________________________________________ Mark A. Thornton © 2012 KAPX 0319Z 39 of 65

Chicago-Mackinac Race ____________________________________________________________________________ Mark A. Thornton © 2012 An Examination Of Two Features Bow Echo Downburst 40 of 65

Chicago-Mackinac Race ____________________________________________________________________________ Mark A. Thornton © 2012 KAPX 0324Z Analyzing A Bow Echo: Close-Up 50 12,500 · · 16.7 kts 41 of 65

Chicago-Mackinac Race ____________________________________________________________________________ Mark A. Thornton © 2012 KAPX 0329Z Analyzing A Bow Echo : Close-Up · · 42 of 65

Chicago-Mackinac Race ____________________________________________________________________________ Mark A. Thornton © 2012 KAPX 0333Z Analyzing A Bow Echo : Close-Up · · 43 of 65

Chicago-Mackinac Race ____________________________________________________________________________ Mark A. Thornton © 2012 KAPX 0338Z Analyzing A Bow Echo : Close-Up 16.3 kts ·· 44 of 65

Chicago-Mackinac Race ____________________________________________________________________________ Mark A. Thornton © 2012 KAPX 0342Z Analyzing A Bow Echo : Close-Up 44.7 kts ·· 45 of 65

Chicago-Mackinac Race ____________________________________________________________________________ Mark A. Thornton © 2012 Analyzing A Downburst 46 of 65

Chicago-Mackinac Race ____________________________________________________________________________ Mark A. Thornton © 2012 KAPX 0342Z Analyzing A Downburst WingNuts was approximately 20 miles northeast of Buoy · · 47 of 65

Chicago-Mackinac Race ____________________________________________________________________________ Mark A. Thornton © 2012 KAPX 0342Z 65 7,400 55,000 ·· · 48 of 65

Chicago-Mackinac Race ____________________________________________________________________________ Mark A. Thornton © 2012 KAPX 0347Z ·· · 49 of 65

Chicago-Mackinac Race ____________________________________________________________________________ Mark A. Thornton © 2012 KAPX 0351Z ·· · 50 of 65

Chicago-Mackinac Race ____________________________________________________________________________ Mark A. Thornton © 2012 KAPX 0355Z 55 5,500 62,000 ·· · 51 of 65

Chicago-Mackinac Race ____________________________________________________________________________ Mark A. Thornton © 2012 KAPX 0401Z ·· · 52 of 65

Chicago-Mackinac Race ____________________________________________________________________________ Mark A. Thornton © 2012 KAPX 0405Z ·· · 53 of 65

Chicago-Mackinac Race ____________________________________________________________________________ Mark A. Thornton © 2012 KAPX 0410Z ·· · 54 of 65

Chicago-Mackinac Race ____________________________________________________________________________ Mark A. Thornton © 2012 Echo Top Imagery (0347Z to 0410Z) 0347Z 0410Z 0405Z0401Z 0356Z 0351Z ··· · ·· 55 of 65

Chicago-Mackinac Race ____________________________________________________________________________ Mark A. Thornton © 2012 Vertical Integrated Liquid Imagery (0347Z to 0410Z) 0347Z 0410Z 0405Z0401Z 0356Z 0351Z · ··· · · 56 of 65

Chicago-Mackinac Race ____________________________________________________________________________ Mark A. Thornton © 2012 The crew had lashed the mainsail to the boom and reduced the size of the head sail in an effort to maintain steerage in the large waves and high winds. Each crew member was wearing a personal flotation device, safety harness and tether. At approximately 04Z, the crew looked upwind and witnessed boats disappearing in a wall of white. The crew attempted to furl the jib, but before the task was completed the boat rolled violently to starboard and capsized. The crew observed 67 knots on the wind speed indicator as WingNuts capsized. Mark Morley and Suzanne Makowski-Bickel were critically injured during the capsize and subsequently drowned. At approximately 0430Z, Sociable heard the distress signals and began the remarkable rescue of the six remaining crew members. Impact On The Fleet -- WingNuts 57 of 65

Chicago-Mackinac Race ____________________________________________________________________________ Mark A. Thornton © 2012 The Downburst Reaches The Shore 58 of 65

Chicago-Mackinac Race ____________________________________________________________________________ Mark A. Thornton © 2012 KAPX 0428Z * 65 2, ASOS 59 of 65

Chicago-Mackinac Race ____________________________________________________________________________ Mark A. Thornton © 2012 Meanwhile, Near Mackinac Island KAPX 0243ZKAPX 0315Z KAPX 0347ZKAPX 0415Z 60 of 65

Chicago-Mackinac Race ____________________________________________________________________________ Mark A. Thornton © 2012 Impact On The Fleet Two (2) deaths during the capsize of WingNuts Forty-seven (47) boats withdrew from the race due to the storms. Thirty-seven (37) boats reported being knocked down, many repeatedly for several minutes at a time. Two (2) boats collided, while twelve (12) boats reported coming very close to a collision. One (1) boat was dismasted. Forty-nine (49) boats reported damage to sails and/or rigging. Six (6) boats indicated their sails were destroyed. 61 of 65

Chicago-Mackinac Race ____________________________________________________________________________ Mark A. Thornton © 2012 The Fleet Was Aware Of The Approaching Storms The potential for storms was mentioned at the pre- race meeting on Friday night. Most of the competitors (85%) indicated they were aware of the approaching storms. Approximately 70% of the boats were tracking the storms on radar. Many long-time sailors reported the lightning was the most intense they had ever experienced. Many sailors mentioned confusion regarding the warnings issued by KAPX and KGRB. 62 of 65

Chicago-Mackinac Race ____________________________________________________________________________ Mark A. Thornton © 2012 Maximum Wind Gusts Across The Region 63 of 65

Chicago-Mackinac Race ____________________________________________________________________________ Mark A. Thornton © 2012 Day Three Severe Weather Probability Issued on Friday, July 15, Storm Reports for July 17-18, A Well-Forecasted Event 64 of 65

Chicago-Mackinac Race ____________________________________________________________________________ Mark A. Thornton © 2012 Thank You 65 of 65