OK - the performance fixes are in place and things are loading MUCH, MUCH faster. My thanks to the team for getting this done and deployed so quickly 
The number of weather forecast tiles that are requested is dependent on your screen size - the larger the screen, the more tiles that are needed to cover the map. On my 14" âretinaâ MacBook Pro display, with my normal browser window, that equates to 24 tiles per forecast. With layer blending enabled (which is likely what youâll want to have enabled), that means 48 tiles.
In my most recent test, all 48 loaded in under 2.5s, where I was the âfirst requesterâ - i.e. tiles had to be created from scratch.
Weâve also added map tile seeding which proactively goes off to âseedâ map tiles into the cache when the new forecast becomes available. Thatâs currently configured for most layers at only lower zoom levels 0-3. Weâll continue to tune that and will prioritize the more popular layers as we get as sense of usage patterns.
Please do send feedback/questions on the weather functionality - weâd love to hear from you.