Halong rapidly intensified this weekend, becoming a super typhoon early Saturday night, local time.
Though it has since weakened, Halong is expected to remain a very dangerous typhoon as it approaches Japan later this week.
There is currently some wind shear affecting the storm which, if strong enough, typically weakens tropical systems. However, Halong is managing to overcome this shear enough to remain a powerful typhoon, even though some minor weakening is possible through Wednesday.
Beyond Wednesday, shear will lessen which could allow Halong to strengthen as it moves through the Ryukyu Islands.
Halong has also enhanced monsoonal rains across the northwest Philippines where flooding will remain a problem through Wednesday; 50-100 mm (2-4 inches) of rain have fallen across Metro Manila since Saturday with local amounts over 300 mm (12 inches) northwest of the city.
http://www.accuweather.com/en/weather-news/japan-in-harms-way-from-super/31488164