Hurricane Matthew has strengthened slightly as it has tracked slowly north towards Haiti. It is making landfall over the southwestern tip of Haiti as a category 4 hurricane on the Saffir-Simpson Hurricane Wind Scale with sustained winds near 145 mph. This makes it the strongest hurricane to make landfall over Haiti since Hurricane Cleo in 1964. In 1980 Hurricane Allen was a similar intensity as it passed close to Haiti, although the eye just kept offshore.
In addition to exceptionally strong winds near the centre, Matthew is expected to bring a storm surge of 2-3 metres to the coast of Haiti, the Dominican Republic and Cuba. Rainfall totals of 500 mm are widely expected and up to 1000 mm in mountainous areas. This is likely to result in severe flooding.
Matthew will pass over the eastern tip of Cuba later today and is then expected to take a leftward turn and start tracking across the Bahamas. Although it may weaken to category 3, it will still be a powerful hurricane and could bring a storm surge over many of the islands of 3-4 metres.
In the longer range there is now an increasing likelihood that Matthew will affect Florida and other parts of the USA east coast late in the week and over the weekend. If and when the eye of the hurricane makes landfall is still uncertain, but even if it is a glancing blow impacts can be expected from strong winds, heavy rain, storm surge and rough seas.
On the other side of the Atlantic, with high pressure dominating the UK weather for at least the next week, Matthew is not currently expected to have any direct impacts on the UK.
Yesterday Typhoon Chaba peaked at category 5 on the Saffir-Simpson Hurricane Wind Scale as it passed across the Ryukyu Islands in the western Pacific. Although the eye passed just to the west of Kume Island, a wind gust of 134 mph was recorded.
Chaba is continuing to track north with only slight weakening. It is expected to turn northeast and could pass over the Korean island of Jeju later today. The southern coast of mainland South Korea is also likely to see some impacts. It is then likely to accelerate along the northern coast of Japan, bringing a spell of heavy rain as it does so.
Official warnings for the latest tropical cyclones in the western North Pacific are produced by the Japan Meteorological Agency. North Atlantic warnings are issued by the US National Hurricane Center. The Met Office routinely supplies predictions of cyclone tracks from its global forecast model to regional meteorological centres worldwide, which are used along with guidance from other models in the production of forecasts and guidance. We also provide updates on current tropical storms via @metofficestorms on Twitter.