It may seem implausible at first glance, but current research in the Department of Atmospheric and Oceanic Sciences at UW-Madison is exploring connections between tropical cyclones (hurricanes) near the Philippines and extreme weather events in southern Wisconsin.
The connection appears to derive from unusual jet stream structures forced by the outflow from the hurricane at high levels in the atmosphere.
Hurricanes are well-organized collections of tropical thunderstorms that take warm, moist air from the lowest levels of the tropical atmosphere and very quickly thrust it nine miles or more above the surface. This rapid upward motion substantially distorts the shape of the tropopause which, in turn, intensifies the normal jet stream located on the northern periphery of the vast hurricane outflow.
The intensified jet, often a very long-lived structure, can become a major weather event produced in the central United States several days later. Currently, we think this type of connection is most likely to occur in spring and fall.
Our incredible windstorm in October 2010 was a clear example of this tropical connection to Wisconsin weather. We are just beginning to explore these ideas in detail and will keep you informed of our results.
