Shortwaves
move from day-to-day and are ÒsteeredÓ by the longwaves. Upper-level regions very supportive of
cyclone development (red shading) Shortwave
troughs (1, 3) along jet axis, near base of longwave troughsÉ They
contain strong upper-level divergence that initiates cyclogenesis!
Longwaves and Shortwaves
Ahrens Fig. 8.23