Atlantic Hurricane Watch

  • Figure 1: Track of Hurricane Ernesto, showing the areas affected by tropical storm force wind speeds (in yellow), and hurricane force winds (in red). Source: NOAA.

    Figure 2: Satellite image of Hurricane Ernesto on 7th August 2012, as it tracked eastwards across the Gulf of Honduras towards Belize and Mexico's Yucatan Peninsula. Source: NASA

    Figure 3. Forecast storm track of Tropical Depression 7, which will be called Gorden when and if it strengthens into a tropical storm. Source: NOAA

  • Atlantic Hurricane Watch
    11.08.2012 13:21


    This year the Atlantic hurricane season got off to a very active start in May and June, with the first time since the records began in 1851 that 4 named storms had formed before the start of July.

    However, despite this early flourish of activity, there was then an extended period of inactivity with no new named storms forming during the whole month of July. This all changed in August with 2 named storms forming since the start of the month. One of these storms, Ernesto, strengthened into a hurricane on the 7th August.

    Hurricane Ernesto formed from a tropical wave in the central Atlantic on August 1st.  It travelled westwards and slowly gained strength, hitting the Lesser Antilles as a tropical storm on the 3rd August. Heavy rains and gusty winds affected the islands with a maximum wind gust of 63mph recorded on St Lucia. No significant damage was reported, but ferry services were cancelled and the airport on the island of Dominica was closed for 2 days.

    The storm then moved away westwards, tracking across the Caribbean Sea between Hispaniola and the northern coast of South America. As the system drew closer to the coast of Belize and the Yucatan Peninsula of Mexico, Ernesto strengthened into a hurricane shortly before making landfall early on the 8th August with mean wind speeds on 85mph.

    The storm produced heavy rain as it tracked across the Yucatan Peninsula and the coast of Campeche Bay, before weakening over the Mexican Highlands. 230mm rain fell at Tuxapan (160 miles north-east of Mecico City) in 24 hours up to 12UTC on August 10th, with 166mm of this falling in just 6 hours. Unsurprisingly this lead to flooding and landslides in places, leading to the deaths of at least 7 people.

    Ernesto then weakened considerably over the Mexican Highlands before entering the Pacific Ocean, where it is expected to regain tropical storm status within the next day. As the system has moved over a new ocean, it will be renamed Hector if it does indeed re-strengthen.

    Currently, another tropical depression is located just to the east of Barbados, and is expected to strengthen into a tropical storm later today or early tomorrow (when it will then be called Gordon), as it takes a very similar track to that of Ernesto a few days ago (see figure 3 for the forecast track). Another area of low pressure is currently close to the Cape Verde islands off the west coast of Africa and is being watched for any future development.

    Closer to home, the weather across the UK is also expected to take a turn for the worse into next week. The high pressure which has produced the warm and fine weather over much of the country during the last couple of days is expected to slowly drift away to the east.

    This will allow low pressure systems to once again move in off the Atlantic. This will begin with a few sharp showers pushing into the far south-west of England later today, with these expected to gradually spread north-eastwards tomorrow.

    An isolated shower is possible in London for the final day of the Olympic Games, but it should stay largely dry with hazy sunshine and temperatures into the mid 20s. It is also likely that conditions will remain dry for the closing ceremony tomorrow evening.

    By: Chris Burton