TEAMG warns Bangkok and surrounding provinces could get 100-150 mm of rain a day on 26-27 September, well above the drainage design of about 60 mm a day. Canals such as Lat Phrao, Rangsit and Saen Saep are near or over their banks. Expect water of 10-20 cm on roads near canals and up to 50 cm in low basins, possibly lasting into Sunday 27 September. The cause is rainwater not draining, not river flooding; the Chao Phraya is at safe levels. For shops and workshops in low-lying or canal-side areas, move stock off the floor, plan for delivery and staff disruption, and keep vehicles out of flooded roads.