Upper air balloon soundings, observed strong directional wind shear, cooling temperatures at high atmospheric levels and the increased potential of CAPE values potentially exceeding 4000 j/kg, levels that are considered favorable for supercells and tornadoes.
the 1999 Oklahoma tornado outbreak – one of the most prolific tornado outbreaks in Oklahoma history
1999 | Oklahoma | 1999 in music | Oklahoma City | Tulsa, Oklahoma | University of Oklahoma | Oklahoma! | Norman, Oklahoma | Governor of Oklahoma | Space: 1999 | The Mummy (1999 film) | 1999 in film | 1999 Pan American Games | Oklahoma City bombing | 1999 ATP Tour | 1999 ICF Canoe Slalom World Championships | tornado | Panavia Tornado | Ontario general election, 1999 | Muskogee, Oklahoma | Ada, Oklahoma | 1999 World Championships in Athletics | 1999 Rugby World Cup | Oklahoma Sooners football | Oklahoma House of Representatives | Oklahoma City Thunder | Stillwater, Oklahoma | Oklahoma Senate | Oklahoma City University | House of Lords Act 1999 |
1999 Oklahoma tornado outbreak – produced an F5 tornado which had winds estimated at 511 km/h (318 mph) by the doppler data of the weather radar