Table 4 Regional comparison of the changes in intensities, translation speeds, and direction of motions of landfalling TCs over Luzon, Visayas, and Mindanao. The results for Luzon Island were based on Wu and Choy (2015)
| Â | Luzon | Visayas | Mindanao |
|---|---|---|---|
Data and methods | Landfalling Luzon TCs at > 15° N are recorded 50 TCs from 1980 to 2014 More frequent storms during JJASO than NDJFM | TC passing through the defined demarcation lines between 10 and 15°N 39 TCs from 1979 to 2020 More frequent storms during NDJFM than JJASO | Landfalling Mindanao TCs 8 TCs from 1979 to 2020 More frequent storms during NDJFM than JJASO |
Intensity | Average intensity at AP is 69.2 kts Decrease in TC intensity at AP versus DP (logarithmic relationship) Estimated intensity drop for TD and TS is less than 10 kts, while for TY is greater than 10 kts 6 cases with intensity increase for Luzon TCs (TS & TD Category) 11 RI and 3 RW (24 h before AP and AP − 6) Intensity drop levels off at DP + 6 | Average intensity at AP is 67.95 kts, while DP is 54.36 kts Decrease in TC intensity at AP versus DP (linear relationship) Average intensity drop for TS is 8.13 kts (− 20.5%), while for TY is 24.29 kts (− 45.5%) Average intensity increase for TS is about 7.5 6 cases with intensity increase for Visayas TCs (6 TS) 21 RI and 3 RW (from genesis to AP) Intensity drop levels off at DP | Average intensity at AP is 63.38 kts, while DP is 53.13 kts Decrease in TC Intensity at AP versus DP (linear relationship) Average intensity drop for TS is 6.67 kts (− 25.0%), while for TY is 23.33 kts (− 25.4%) Average intensity increase for TS is 5 kts 2 cases with intensity increase for Mindanao TCs (TS) 2 RI and 1 RW (from genesis to AP) Intensity drop levels off at DP + 6 |
Translational Speed | Average TS at AP is 12.8–14.8 kts (95% CI) TC takes about 6 to 9 h to transverse Luzon TC accelerates (decelerates) as it approaches (departs) from Luzon Island | Average TS at AP is 11.09–13.79 kts (95% CI) TC takes about 17 to 30 h to traverse Visayas TC decelerates as it approaches and departs Visayas | Average TS at AP is 11.12–16.24 kts (95% CI) TC takes about 7 to 14 h to traverse Mindanao TC decelerates as it approaches and departs Mindanao |
Direction of Motion | Weaker TCs have a greater tendency to be deflected at AP compared to stronger TCs Stronger TCs have a greater tendency to be deflected at DP than AP Negative correlation at DP versus AP direction change (opposite deflection) Higher TC deflection tendency at DP than at AP | Weaker TCs have a greater tendency to be deflected both at AP and DP compared to stronger TCs No correlation at DP versus AP direction change Similar TC deflection tendency at AP and aYangt DP | Stronger TCs have a greater tendency to be deflected at AP than DP All TCs at TY are deflected to the right at AP Two TCs deflected to the left at DP Positive correlation at DP versus AP direction change (same direction deflection) Higher TC deflection tendency at AP than at DP |