The hypothesis that JAE events can occur outside of the western North Pacific TC context with similar downstream impacts to those associated with TCs is tested next. The global climatology showed that JAEs were found throughout the year, particularly in fall and winter months, and in four preferred regions: near Japan, in the central North Pacific Ocean, over the Great Lakes region of North America and just east of Australia. Composite increases in downstream meridional index and 250-hPa wind speed were similar to those reported by A2013 for western North Pacific recurving TCs. This suggests that a prolonged period of strong negative PV advection by the divergent component of the wind at any time of year can engender high impact downstream weather. A few illustrative winter examples are shown.
Heather M. Archambault, Lance F. Bosart, Daniel Keyser, and Jason M. Cordeira, 2013: A Climatological Analysis of the Extratropical Flow Response to Recurving Western North Pacific Tropical Cyclones. Mon. Wea. Rev., 141, 2325–2346.
Supplementary URL: http://meteo.pr.erau.edu/gfs/loop_pmap_gfs_jet.gif