Typhoon Rammasun (WP092014) went through a rapid intensification cycle over the last 24 hours, increasing from 65 to 100 knots (120 to 185 kph). The impact estimates for the Philippines likewise increased dramatically, from around $1 Billion to $4.3 Billion, based on the Joint Typhoon Warning Center track and intensity estimates. Manila is still directly in the path of the storm:
Rain and flooding are always an issue in the Philippines with tropical cyclones. How much damage depends on the exact track, especially for storm surge flooding. Lamon Bay can expect 2 to 3 meters, and the northwestern parts of Manila Bay could see 2 meters – but if the track wobbles north of the Capital, the peak surge location could shift to the Manila shorefront.
While the tracks across the islands are almost the same, the Japan Meteorological Agency forecast is somewhat less enthusiastic than the JTWC with respect to intensity, and on that forecast track/intensity the impacts to the Philippines are just over $2.3 Billion USD. The HWRF objective track model generated $2.7 Billion in impacts.
When looking at impacts, and trying to put things in perspective, the raw numbers don’t tell the full story. A $2 or even $5 Billion USD storm, while obviously a disaster for those in the path, is not a catastrophe for a country like the United States. However, based on the difference in relative size and development of the economies, $4.3 Billion event in the Philippines is roughly the equivalent of a $50 Billion USD storm; in other words, on the order of a Sandy type event. So this is potentially a big deal.
Looking ahead, the storm is forecast to make landfall on northern Hainan Island (if the JTWC forecast holds, and their intensity estimates have been way off on this storm, that would mean Hong Kong would be on the fringes of the wind field). China could expect nearly $2 Billion USD in damage. Vietnam would be up next, and damages of $800 Million, with the decaying storm passing over Hanoi. Again, a lot of uncertainty in those forecasts because, while the track guidance is fairly consistent, the intensity estimates are not. The HWRF model forecasts a bit stronger intensity on landfall in China, and my ISTANU model estimates over $3 Billion in damage. But Vietnam is the big question – HWRF maintains the intensity further inland, with a direct hit on Hanoi and a whopping $5 Billion in damage for Vietnam (that would be a Katrina sized disaster for the country). I don’t think I believe that forecast, but it’s possible.