Reasons for Different Predictability of Tropical Cyclone Tracks in the Western NorthPacific and Atlantic Oceans

Recent several studies have focused on the predictability of tropical cyclone track forecast. As a response to the question issued by Landsea and Cangialosi (2018) about "the approaching limit of predictability for tropical cyclone (TC) track prediction is near or has already been reached", Zhou and Toth (2020) (short for ZT20) and Yu et al. (2022) (short for Y22) have found that the limit of predictability for TC track
prediction has not been reached both in Atlantic (ATL) and Western North Pacific (WNP) basins. However, the predictabilities are different in two basins, as ZT20 found that the 1 day's improvement can be obtained through 10 years in ATL, while Y22 found that 2 days' improvement can be obtained through 15 years in WNP. What causes this difference?
This study first checks the predictability of TC track in WNP using the same method as ZT20. Then the results in both two basins are compared and analyzed. The track error growth rate in WNP is found to be higher than that in ATL, suggesting a low predictability in WNP. Possible reasons for the difference are explored.
The results suggested that TCs in WNP basin have averagely larger sizes, stronger intensities, lower-latitude locations, and poorer forecast skills of their guided flows. All these factors contribute to the larger track error growth rate. Moreover, it is pointed out
that as the improvement of forecast skills mainly due to the reduction of initial analysis errors, although a lower predictability is found in WNP, the forecast skill improvement in WNP is faster than that in ATL.