05/16←  2025-05-17 CWB twsfc map  →05/18

2025-05-17 00 UTC	2025-05-17 03 UTC
2025-05-17 06 UTC	2025-05-17 09 UTC
2025-05-17 12 UTC	2025-05-17 15 UTC
2025-05-17 18 UTC	2025-05-17 21 UTC