Monster super typhoon Sanba aims at Okinawa and South Korea Satellite image of super typhoon Sanba in the western Pacific, south of South Korea and Japan (NOAA) A large, dangerous typhoon has rapidly gained strength in the western Pacific. Super typhoon Sanba, positioned 690 miles south of Kadena Air Force base, Japan, has peak winds of 155 mph, the equivalent of strong category 4 hurricane, on the cusp of category 5. The storm is headed due north, on a path to pass very near the island of Okinawa, Japan late Saturday or early Sunday local time. After that, the storm is forecast to continue due north towards the southern tip of South Korea Monday, although southern mainland Japan is within the range of possible tracks. The major concern with this typhoon is its destructive intensity. Joint Typhoon Warning Center (JTWC) commentary describes a "very symmetric system" with a "persistent" eye surrounded by "a thick ring of deep convection" - readily apparent in satellite imagery. JTWC says the environment "remains favorable" for additional intensification. Peaks winds are forecast to reach 160 mph in the next 12 hours - which is category 5 strength. The storm is predicted to maintain this intensity for up to 36 hours, before a slow weakening trend begins due to arrival in cooler waters. Forecast track for super typhoon Sanba (Joint Typhoon Warning Center) Assuming Sanba tracks near Okinawa as predicted, it may well contend with category-4 type conditions. "Oooh, baby, this storm is becoming a whopper, to borrow a 1930s expression," writes Stars and Stripes typhoon blogger Dave Ornauer. AccuWeather notes Okinawa has already dealt with two storms this typhoon season: Bolaven and Haikui. But this storm could pack a bigger punch. "While the island is well-prepared for typhoons, damage, power outages and flooding are likely in this scenario,"AccuWeather writes. Peaks winds may drop down to Category 2 levels by the time the storm makes landfall in South Korea or southern Japan, but extreme rainfall totals are possible. "The worst case scenario is a widespread flooding disaster," AccuWeather meteorologist Jim Andrews said. In the longer-range, the storm may have implications for the weather in the eastern United States, perhaps playing a role in the cool pattern forecast to develop writes Grand Rapids meteorologist Bill Steffen: Typhoons that move north and then northeast in the Western Pacific can change the upper level wind pattern...creating a trough south of Alaska, a ridge over the Western U.S. (where it gets quite warm) and then a trough over the Great Lakes/Northeast. I think Sanba will do that...