Marine Institute

Record individual wave measured in South East by M5 weather buoy during Ophelia

Record wave heights were captured by the Irish Weather Buoy Network during Hurricane Ophelia on Monday 16th October, causing one of the five weather buoys to break it moorings. The highest wave was recorded off the Irish coastline at 16.00 on Monday when the M5 weather buoy off the South East coast, measured a record individual wave (Hmax) of 17.81m* and a record significant wave height (Hs) of 12.97m **. The M5 weather buoy subsequently broke away from its mooring and the Marine Institute coordinated the retrieval process as a matter of urgency. The M5 was recovered yesterday by the MV Puffin of Fastnet Shipping (Waterford) and brought ashore last night.

As Ophelia moved northwards, the M2 buoy to the east of Dublin also experienced a record significant wave height (HS )** of 6.64m measured at 18.00 on Monday 16th.The Irish Weather Buoy Network

Earlier in the day, at 12.00, the M3 buoy, off the South West coast measured an individual wave height of 13.59m, although this was not a record wave for this buoy.

In addition to measuring the waves, the weather buoy network, which is managed by the Marine Institute provides further vital atmospheric (including wind speed) and oceanographic information to support both maritime safety and, importantly in storm events such as Ophelia, help to validate the weather forecast models run by Met Éireann providing guidance to the national emergency planning efforts.

The Irish Weather Buoy Network is designed to improve weather forecasts and safety at sea around Ireland. The buoy network also provides operational ocean models, shipping bulletins, gale and swell warnings as well as data for general public information and research.

The network is managed by the Marine Institute in collaboration with Met Éireann, the UK Met Office and the Irish Department of Transport, Tourism and Sport (DTTAS). Real time data from the network can be found here.

Ends

*Hmax = the highest individual wave.
**HS = significant wave height = the average of the highest one-third (33%) of waves (measured from trough to crest) that occur in a given period.