Large Tropical Storm Krosa Moves Toward Southwest Japan;

Large Tropical Storm Krosa moved toward southwestern Japan on Tuesday.  At 5:00 p.m. EDT on Tuesday the center of Tropical Storm Krosa was located at latitude 28.7°N and longitude 133.4°E which put it about 330 miles (530 km) south of Kochi, Japan.  Krosa was moving toward the northwest at 8 m.p.h. (13 km/h).  The maximum sustained wind speed was 65 m.p.h. (105 km/h) and there were wind gusts to 80 m.p.h. (130 km/h).  The minimum surface pressure was 965.

The circulation around Tropical Storm Krosa was large.  Krosa has a broad center of circulation which spanned almost 120 miles (195 km).  Several bands of showers and thunderstorms appeared to be consolidating into a broken ring around the broad center.  The strongest winds were occurring in the broken ring.  Other bands of showers and thunderstorms were revolving around the broad center of circulation.  Winds to tropical storm force extended out about 265 miles (425 km) from the center of circulation.

Tropical Storm Krosa will move through an environment favorable for intensification during the next 12 to 24 hours.  Krosa will move over water where the Sea Surface Temperature is near 28.5°C.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear.  Tropical Storm Krosa is under an upper level ridge which is enhancing the upper level divergence.  However, the large, broad center of circulation will limit the rate of any intensification.  Krosa could strengthen into a typhoon before it reaches southwestern Japan.

Tropical Storm Krosa is moving around the western end of a subtropical ridge over the Western North Pacific Ocean.  Krosa will move more toward the north when it reaches the western end of the ridge.  On its anticipated track Tropical Storm Krosa could reach southwestern Japan within 18 to 24 hours.  Krosa could be a typhoon by that time.  Tropical Storm Krosa will bring gusty winds and heavy rain to parts of Kyushu, Shikoku, and western Honshu.  Heavy rain is likely to cause flooding in some location, especially in areas with steeper slopes.