Table 1: Periods 𝑇 𝑑 𝑟 and growth rates 𝜔 𝑑 𝑖 of selected modes for the 1949–68 NCEP/NCAR basic state with standard parameterizations ( 𝐾 𝑑 = 2 . 3 3 8 × 1 0 1 6  m4 s−1, 𝑄 𝑑 𝐹 = 1 5 0 0 K, 𝐶 𝑑 𝐹 = 5 × 1 0 4 K m−1), their mode number, and class of mode. Also shown are the largest pattern correlations 𝐴 𝑐 between a given mode and the modes for the 1975–94 NCEP/NCAR basic state with standard parameterizations and the 1975–94 mode for which the pattern correlation is largest as well as the change in the growth rate Δ 𝜔 𝑑 𝑖 .

ClassMode 𝑇 𝑑 𝑟 𝜔 𝑑 𝑖 𝑇 𝑑 𝑟 𝜔 𝑑 𝑖 𝐴 𝑐 Mode Δ 𝜔 𝑑 𝑖

SH cyclogenesis11.200.42501.300.28240.91489−33.5%
ML blocking306.110.25666.250.22790.459721−11.2%
HL blocking87.400.34958.020.33170.83424−5.1%
HL blocking115.220.31845.080.31010.84686−2.6%
African EW224.140.28813.830.30710.79597+6.6%