Satelite image of Typhoon on Ma-on along with forecast track. (Cooperative Institute for Meteorological Satellite Studies)

The Joint Typhoon Warning Center (JTWC) describes a healthy storm with “excellent equatorward outflow as well as enhanced northwesterly outflow.” This outflow serves as an important mechansim for releasing energy and supporting storm intensification.

JTWC projects the storm will reach peak intensity in about 48 hours, with winds to 140-145 mph. Should the storm attain maximum winds of 150 mph, it would be classified as a super typhoon. Even as the storm nears mainland Japan and encounters some hostile wind shear, only slight weakening is forecast due to warm sea surface temperatures.

Landfall intensity is predicted to be around the category 3 hurricane level, with maximum sustained winds of 125 mph. The JTWC forecast indicates Ma-on will come ashore over central Shikoku, but there is a large cone of uncertainty and landfall could occur over almost any area along Japan’s east coast, or, if the storm makes a strong enough right turn when it turns poleward, may only skirt coastal areas.

But it is unlikely Ma-on will elude Japan entirely and a direct strike appears to be the most likely scenario. Coastal areas should be prepared for the possibility of a major storm surge, damaging winds and flooding rain. And flooding rains may well affect inland areas as well.

The storm threatens to come on the heels of not only the March earthquakes and tsunami, but also a major heat wave that has afflicted the country. Bloomberg reported Thursday: “Deaths from heatstroke in Japan quadrupled in the early part of summer as temperatures rose and air conditioners were switched off in line with government appeals to curb electricity usage to avoid power blackouts.” In the last 10 days of June, temperatures were nearly four degrees above average in Tokyo, the highest since at least 1961 according to the Bloomberg article.