from Thursday, November 24 at 3:00 p.m. until Thursday, November 24 at 6:00 p.m.

The situation

In connection with a very deep low pressure near Ireland, the sea near the Atlantic has become strong, with waves of 6 to 9 meters reaching Cape Breton since this morning. Stronger afternoon winds increase this swell as an active disturbance passes. This situation would have been classic for this season, but it coincided with spring high tide (high tidal coefficients at 96 at 5 o’clock high tide in Brittany). Hence extreme caution is required as there is a possibility of heavy flooding at high tide (up to 2 hours before and 2 hours after) along the coast.
Winds are blowing this afternoon at normal speeds for this time of year. Maximum winds are forecast this afternoon between 80 and 90 km/h, turning west from the south-west sector, with peaks of 100 km/h on the headings.

monitoring

At 3 p.m., Cold front Stretching from the northern Bay of Biscay to southern England, now crossing Brittany with temporarily heavy rain. Southerly winds blow strongly from the front, with gusts of 70 to 80 km/h from southern Finistère to the Cotentin. The sea is still very strong with waves of 6 to 7 meters off the Finistère and Morbihannais coasts. The risk of drowning increases with the onset of high tide.

in the afternoon, Disturbance reached Brittany due to the strength of the wind and the onset of rain, which at first was very light. Southwesterly winds 60 to 70 km/h and 80 to 90 km/h offshore (Finister and Morbihan). Wind gusts of 100 km/h at Point du Raz (29). The sea continued to be strong with waves at 7m off Finistère. There was no impact on the coast as the tide receded in the afternoon.

Today at 7 o’clock in the morning, A deep depression at 970 hPa was approaching Ireland. Its vast area brought strong winds to large areas of the North Atlantic, causing very strong and prolonged swells (this region is called a “fetch”). Waves reached 8 to 9 meters with a period of 13 seconds at the Piers Noires buoy near Ossant Island.

The low pressure cyclone was already clearly visible in satellite images. On the other hand, the disturbance, bringing strong winds and rain, was rapidly approaching the tip of Brittany, 100 km away.

evolution

A disturbance with rain and wind passes over Brittany this afternoon. But the risk defined in this alert is really about strong waves and the potential for inundation around high tide (3pm to 6pm). Then the wind will slowly die down and the tide will be low so the waves will die very slowly overnight.