Typhoon BANYAN just made landfall near Kamogawa City in Boso Peninsula, according to Japan Meteorological Agency. This seems to be just a barely landfall, but in any case, this typhoon became the first typhoon that made landfall on Japan during the 2005 typhoon season.

Typhoon BANYAN is heading toward Kanto, but its maximum wind is getting smaller. Rainy clouds, however, are stretching around the periphery rather than the core, so it may be more important to pay attention to where the clouds are, rather than where the center of the typhoon is. By the way, due to the approach of the typhoon to Tokyo, the web site is extremely congested today, which may result in your inconvenience. In particular around 9:00 AM, some servers stopped due to the excessive amount of traffic, so we added one server to cope with the traffic. We hope this will improve the response time.

Looking at the latest animation of Geostationary Meteorological Satellite Image Around Japan, (e.g. Infrared 1), rainy clouds that have been in the east of the typhoon started to turn around (?) to the north of the typhoon this evening, and they are drawing near between Tokai and Kanto areas. Or it may be that the clouds of the typhoon merged with the clouds of the front. This situation indicates that we should be on the alert for heavy rains, even if the wind, or pressure, of the typhoon may not seem to be strong. It is very likely that the typhoon will make landfall tomorrow, so please refer to early warnings issued by Japan Meteorological Agency.

Typhoon BANYAN is now approaching mainland Japan without intensifying too deeply. Thick clouds have been formed in the east, while less clouds were generated in the west, and the typhoon is still showing im-balanced shape. If we check the surface wind, the areas of strong winds and weak winds are interlaced, so in spite of the large area of strong winds, the structure of this typhoon is not well balanced. These facts indicate that this typhoon is a pan-bottom-type typhoon, which has the larger slope of pressure (stronger wind) in the periphery rather than the core. In the end, the gigantic spiral in the first could not concentrate on the single center.

Typhoon BANYAN yesterday showed a loose shape due to its bulky size, but the cloud system is now gradually being organized into two parts, the core cloud in the center and the thick cloud band in the east. The area of 50kt winds or more extends almost to this cloud band, and this indicates that the structure of the typhoon may cause strong winds and heavy rains in distant areas from the center.

Typhoon BANYAN's clouds are still dispersed, but gradually thick clouds are beginning to be formed in the center. It seems the typhoon starts intensification moderately from today.

Typhoon BANYAN was born in east of Philippines. This typhoon shows a gigantic spiral much larger than the previous typhoon, Typhoon NALGAE. Looking at images on the time Typhoon BANYAN was born, the central pressure was the identical value of 992hPa for Typhoon NALGAE and Typhoon BANYAN, but the size is completely different, and Typhoon BANYAN was much larger than the other. If you compare the maximum sustained wind, however, you find that the smaller one, Typhoon NALGAE, was 45kt, while the larger one, Typhoon BANYAN, was only 35kt. You may guess that the larger one has the stronger wind, but, generally speaking, the wind speed is dependent on the slope of pressure, so a larger typhoon may have a weaker wind. A typhoon, which is gigantic from the beginning, has the possibility of intensifying into a very large and strong typhoon. But in other cases, a too large typhoon results in a typhoon whose center cannot be sharply identified, and becomes a large but not a strong typhoon. The current forecast says the central pressure will not deepen steeply, so the latter case might be assumed. The forecast may change from time to time, however, so we need to keep attention on this typhoon.