Category 2 Francisco Brushing Guam, and is a Long-Range Threat to Japan

Category 2 Typhoon Francisco is steadily intensifying over the warm waters of the Western Pacific about 160 miles southwest of Guam. The typhoon is expected to make its closest approach to Guam on Friday morning (local time), bringing sustained winds of 35 - 45 mph and heavy rain, as the storm heads north-northeast at 9 mph. Long range radar out of Guam and satellite loops show that Francisco is well-organized with an impressive area of heavy thunderstorms and a prominent eye. With warm waters that extend to great depth and low wind shear, continued strengthening is likely, and Francisco is forecast to become a major Category 4 typhoon by Saturday as it turns northwest towards Japan. Both the GFS and European models predict that Francisco will hit Japan on Wednesday or Thursday next week, though there is very high uncertainty in the storm's track that far into the future. Francisco's formation gives the Western Pacific 27 named storms so far in 2013, which is the average number of named storms for an entire year. The last time there were more than 27 tropical storms or typhoons in the Western Pacific was in 2004, when there were 32.


Figure 1. View of Typhoon Francisco from the long range radar out of Guam.


Figure 2. MODIS satellite image of Typhoon Francisco, taken at approximately 03 UTC on October 16, 2013. At the time, Francisco had top winds of about 85 mph. Image credit: NASA.

18 dead, 40+ missing in Japan after Typhoon Wipha
Typhoon Wipha roared past Japan on Tuesday as a Category 1 typhoon, bringing destructive winds and high rains that triggered flooding being blamed for at least 18 deaths. Most of the deaths occurred on Izu Oshima island, about 75 miles south of Tokyo. An astonishing 33.44" (824 mm) fell in just 23 hours on the island, triggering flash floods and mudslides that killed 17 people and left at least 40 missing. During one incredibly wet 6-hour period, 549.5 mm fell, setting a new 6-hour precipitation record for Japan. The previous record was 502.0 mm at Tarama, Okinawa, on April 28, 1988. According to weather records researcher Maximiliano Herrera, the 24-hour total at Oshima Island was the third highest 24-hour rainfall for Japan on record; the record is 851.5 mm at Yanase (Kochi Prefecture) on 19 July 2011, and 2nd place is the 844 mm that fell at Takeshi (Nara) on 1 August 1982. Wipha is the fourth named storm to hit Japan so far in 2013, and the deadliest typhoon to hit Japan since Typhoon Tokage of October 2004. An average of 2.8 tropical storms or typhoons per year hit Japan during the period 1951 - 2003. Japan's record busiest year was 2004, when ten named storms hit, six of them at Category 1 or higher strength. Jeffrey Hayes has put together a nice summary of Japan's typhoon history.

The Atlantic is quiet
None of the reliable computer models for forecasting tropical cyclone genesis is predicting development over the next five days. NHC is giving 10% odds that an area of disturbed weather (Invest 99L) about 200 miles north-northeast of Bermuda headed northeast out to sea, will develop. During the last few days of October and the first week of November, the Madden Julian Oscillation (MJO), a pattern of increased thunderstorm activity near the Equator that moves around the globe in 30 - 60 days, is predicted to transition into a phase that will bring an increase in upward-moving air over the Atlantic, boosting the odds of tropical storm formation. The most likely area for formation will be in the Western Caribbean or Gulf of Mexico.

Jeff Masters