On the relationship between North Atlantic baroclinic growth rate regimes and surface cyclogenesis
Concentrating solely on the cold season months (DJFM), we find 103 events with standardized anomalies greater than two. Most events last one day, with a maximum length of 10 days. Cyclone data are provided by the National Snow and Ice Data Center for the years 1958-2008. Each of the extreme DJFM σm areal coverage events within this time period are lag-correlated with both cyclone numbers and cyclone deepening rates in the basin on each day. The DJFM events lasting longer than 3 consecutive days (n=8) are characterized by above average occurrences of explosive cyclogenesis near the end of the events. For the duration of each event the number of surface cyclones within the basin was fewer than average, with the extant cyclones deeper than average and anomalously high frequencies of explosive cyclogeneses.