MET forecasts for Irish coastal waters

The Sea Area Forecast issued by Met Éireann covers Irish coastal waters out to 30 nautical miles. It also includes the Irish Sea area.

Sea Area Forecasts are issued and broadcast live on RTÉ Radio 1 at:

• 06:02
• 12:55
• 16:57
• 23:55

Irish Coast Radio Stations make a prior announcement of weather forecasts on Marine VHF Radio Ch16 and then broadcast the forecast on the named relevant VHF Radio working channel.

Met Éireann Sea Area Forecasts are broadcast every 3 hours. They begin at;

• 01:03
• 04:03
• 07:03
• 10:03
• 13:03
• 16:03
• 19:03
• 22:03

GaleWarning broadcasts are also preceded by an announcement on Marine VHF Ch16. They are broadcast on receipt and are repeated at the next one of the following times:

• 00:33
• 06:33
• 12:33
• 18:33

Small Craft Warnings

Small Craft Warnings are issued (April-September inclusive) if winds of Beaufort Force 6 (min. mean of 22 knots) are expected up to 10 Nautical miles offshore.

The latest Sea Area Forecast and Gale Warnings (if any) are available from Met Éireann.

A description of the meteorological situation over Ireland at the stated time and of adjacent weather systems, e.g. depressions, anticyclones or frontal troughs, which are expected to have an influence on the forecast areas during the following 24 hours.

Explanation of some terms used here are:

• imminent: within 6 hours
• soon: between 6 and 12 hours
• later: between 12 and 24 hours.

The speed of movement of pressure and frontal systems is described as follows:

• slowly: up to 15 knots
• steadily: 15 to 25 knots
• rather quickly: 25 to 35 knots
• rapidly: 35 to 45 knots
• very rapidly: greater than 45 knots

The general forecast follows giving wind, weather and visibility for all coastal waters and the Irish Sea.

Descriptions of visibility mean the following:

• good: more than 5 nautical miles (9km)
• moderate: 2 5 nm (4 9 km)
• poor: 0.5 to 2 nm (1 to 4km)
• fog: less than 0.5 nm (1,000metres)

(From a selection of the following stations)

• Malin Head
• Dublin Airport
• M2 Buoy at 53.5˚ North, 5.4˚ West [53˚ 28.8N, 05˚ 25.5W]
• Rosslare
• Roches Point Automatic
• Valentia
• M3 Buoy at 51.2˚ North, 10.5˚ West [51˚ 13N, 10˚ 33W]
• M1 Buoy at 53.1˚ North, 11.2˚ West [53˚ 07.6N, 11˚ 12W]
• Belmullet
• M4 Buoy at 54.7° North, 9.1°West [54° 40N, 9° 04W]

The coastal reports, at the stated time, include:

1. Wind direction on the 16 point compass and speed in knots

2. Weather

3. Visibility in nautical miles and tenths of,

4. Pressure in hectopascals (millibars).

5. Pressure tendency, which describes the change in pressure over the past 3 hours, according to this scale:

• 0.0 0.4hPa = steady
• 0.5 1.9hPa = rising/falling slowly
• 2.0 3.4 hPa = rising/falling
• 3.5 5.9 hPa = rising or falling rapidly
• 6.0hPa or greater = rising /falling very rapidly.

Met Éireann issues Gale warnings for Irish coastal waters, which are regarded as extending 30 miles out from the coastline, and the Irish Sea or part thereof as shown on the map.

• gale warnings are issued if winds of Beaufort Force 8 are expected
• strong gale warnings are issued if winds of Beaufort Force 9 or frequent gusts of at least 52 knots are expected
• storm force warnings are issued if winds of Beaufort Force 10 or frequent gusts of at least 61 knots are expected
• violent storm force warnings are issued if winds of Beaufort Force 11 or frequent gusts of at least 69 knots are expected
• hurricane force warnings are issued if winds of greater than 64 knots are expected