Tropical Depression Co-May (11W) – Tropical Cyclone Advisory #16: 0000 UTC 31 July 2025

…Co-May’s long and strange journey is nearly at an end…

Current storm information:

• Position: 31.2°N 120.4°E

• Movement: WNW at 5 knots (10 km/h)

• Intensity: 30 knots (55 km/h)

• Central pressure: 988 hPa

Trend:

• Rapid weakening is forecast during the next 24 hours, and Co-May should become a remnant low later today.

Discussion:

Co-May has continued to push inland over eastern China and has recently crossed Taihu Lake. Crossing the lake has actually helped Co-May redevelop some convection, but it’s only a small amount, and Co-May is well on its way to becoming a remnant low. The circulation remains fairly well defined, but is almost fully embedded in a dry air mass, and so it’s only a matter of time before Co-May is no longer able to generate convection. There have not been any recent reports of tropical storm force winds, so the intensity is lowered to 30 kts.

Co-May is forecast to continue moving slowly west-northwestward under the influence of a TUTT cell to the southwest and a mid- to upper-level ridge to its east. The circulation should continue to spin down as it moves further inland, and Co-May should become a remnant low later today. The remnant low should dissipate on Friday. 

Forecast positions and maximum winds

• 00 hrs: 31.2°N 120.4°E – 30 kts inland

• 12 hrs: 31.6°N 119.5°E – 25 kts Post-tropical/remnant low inland

• 24 hrs: Dissipated