Over the weekend Hurricane Matthew made headlines as it became the first hurricane in the Atlantic or Caribbean to reach category 5 on the Saffir-Simpson Hurricane Wind Scale since Felix in 2007. Although its intensity soon dropped back slightly, it is still maintaining category 4 strength with sustained winds currently near 130 mph.

Matthew is moving slowly northwards in the Caribbean Sea with the eye expected to move over or just to the west of the western tip of Haiti on Tuesday. However, in advance of this bands of heavy rain are already moving across Haiti, the Dominican Republic and Jamaica. Rainfall totals of 400-600 mm are likely in many areas with 1000 mm possible in isolated locations. This is likely to cause flash flooding and mudslides. Coastal areas in the region will also see a storm surge of 1-2 metres widely with 4-5 metres possible in some locations.

The last hurricane to directly impact Haiti was Tomas in 2010. Tomas caused flooding, property damage and some loss of life, although was less intense than Matthew is expected to be at its closest approach to the country.

Matthew is expected to remain a ‘major’ hurricane (at least category 3) as it crosses eastern Cuba and the southern Bahamas by mid-week. Beyond that there is some uncertainty as to the track of Matthew. The latest consensus of forecasts is that the centre of the hurricane will stay offshore of the USA, but at this stage landfall cannot be completely ruled out.

Hurricane Matthew south of Haiti and Jamaica on 3 October 2016 . Image courtesy of NOAA

Since high pressure is set to dominate the UK weather for at least the next week, no direct impacts of Matthew on the UK are expected at this time.

Typhoon Chaba

Whilst attention has been focused on Hurricane Matthew, Typhoon Chaba has been strengthening in the western Pacific and is now a stronger tropical cyclone than Matthew having just attained category 5 status on the Saffir-Simpson Hurricane Wind Scale.

Chaba is expected to pass to the west of the Japan’s Okinawa Island today, but could pass directly over the smaller island of Kume which has about 8000 residents. As is often the case with tropical cyclones of this strength and size, storm surge and rainfall of several hundred millimetres is likely to accompany the exceptionally strong winds near the centre of the typhoon.

Typhoon Chaba seen southwest of Okinawa Island on 3 October 2016. Image courtesy of NOAA

The latest forecast track takes Chaba north then northeast. It is likely to pass very close to south-western Japan and South Korea on Tuesday and Wednesday. Japan in particular could see some large rainfall totals with the risk of flooding as Chaba moves along the length of the country during mid-week.

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.