After the unsettled conditions caused by storm Ashley over the past weekend, calm weather will return to the North Sea this week. As a result, workable windows will emerge for many offshore operations. However, heading into the weekend, the uncertainty in the forecast increases significantly.
A strong high-pressure area will build over the Bay of Biscay on Tuesday, slowly tracking ENE over the far south of the North Sea and reaching central Europe later on Wednesday. The associated ridge will mostly linger over the North Sea until at least Friday.
Due to the position of the high-pressure system, wind speeds across large parts of the North Sea will mostly remain below 20 knots. At the same time, significant wave height (Hs) in the southern half of the North Sea will stay below 2 meters. In the north, however, Hs can reach up to 3 meters, mainly due to a longer fetch.
From the weekend onwards, the uncertainty in the forecast increases significantly. A front over Ireland moves westward and settles over the UK. The American weather model shows the front moving further eastward across the North Sea, leading to a significant increase in wind speed and Hs rising to 3.5 meters over the southern North Sea. In the European weather model, however, high pressure over central Europe remains stronger, causing the front to dissipate over the UK, which would result in calm conditions over the North Sea during the weekend.
Which of the two weekend scenarios will materialize is still uncertain. However, until Friday afternoon, calm weather is expected over most of the North Sea. During this period, there will be plenty of workable windows available. Not bad at all for the end of October.
Figure 1: Mostly calm weather this week.
