A new paper has been accepted which documents a newly recognized relationship between a circulation pattern [the Madden-Julian Oscillation (MJO)] and hurricanes in the Atlantic Ocean basin. This study illustrates again why a simple climate metric such as the global average surface temperature trend cannot inform us of hurricane activity. Hurricanes depend on regional atmospheric and ocean conditions in their vicinity at any given time. This new paper offers promise of an improvement in hurricane forecasts out to a couple of weeks in the future.
The paper is
Klotzbach, Philip J., 2009: On the Madden Julian Oscillation – Atlantic Hurricane Relationship, Journal of Climate (accepted).
The abstract reads
“The large-scale equatorial circulation known as the Madden-Julian Oscillation (MJO) has been shown to impact tropical cyclone activity in several basins around the globe. In this paper, we utilize an MJO index created by Wheeler and Hendon to examine its impacts on tropical genesis and intensification in the Atlantic. Large differences in frequency and intensity of tropical cyclone activity are seen, both in the tropical Atlantic as well as in the northwest Caribbean and Gulf of Mexico depending on the MJO phase. Coherent changes in upper-and lower-level winds and relative humidity are likely responsible for these differences. Since the MJO shows potential predictability out to about two weeks, the relationships discussed in this paper may be useful for short-term predictions of the probability of tropical cyclone activity in the Atlantic as a complement to the already available longer-term seasonal predictions. “