Thursday, 15 August 2002: 4:59 PM
Mid-level dry intrusions as a factor in tornado outbreaks associated with landfalling tropical cyclones from the Atlantic and Gulf of Mexico
The potential for landfalling tropical cyclones to produce tornadoes has been documented by various researchers. Some storms produce outbreaks of tornadoes while others produce few or none. Various authors over the past three decades have suggested the probable role of mid-level dry intrusions in tornado outbreaks associated with landfalling tropical cyclones. It has been suggested that mid-level dry intrusions have the potential to substantially alter the thermodynamic structure of the tropical cyclone environment (enhancing CAPE and surface-based instability).
Defining an outbreak as twenty or more tornadoes occurring before, during and after landfall, examination of eleven historical outbreak cases (for storms making landfall along the Gulf of Mexico and Atlantic coast) found that nine of the eleven cases offered clear evidence of a mid-level dry intrusion over the area of the tornado outbreak. Recurrence of the distinctive pattern seen in these cases should heighten forecaster vigilance when seen operationally as a storm approaches and makes landfall.
Supplementary URL: http://www.vvm.com/~curtis/AMSTCTor.html