Low pressure will continue to affect the North Sea at the start of the second week of 2025, causing unsettled conditions and occasional local uncertainties. By the weekend, high pressure will dominate, bringing calm conditions to most of the North Sea. However, the northern part of the region may still experience the passage of frontal troughs at times.
A deep low-pressure area to the northwest of Denmark will move northeast, lingering over southern Norway on Tuesday. By Wednesday, the system will shift eastward, merging with a newly developing secondary low over northwestern Russia.
The low-pressure system will result in unsettled weather across the entire North Sea. As shown in Figure 1 above, winds in the most parts of Fair Isles, Forties, Dogger, Fisher and German Bight regions are expected to exceed 35 knots, with gusts reaching over 50 knots. Significant wave heights in these areas may exceed 5 meters, making it a key factor to consider during this period.
The rest of the North Sea will be somewhat calmer, though winds may still rise to 30 knots, with gusts up to 40 knots. Wave heights in these regions may locally increase up to 4 meters.
As the previously mentioned low-pressure system moves away from the North Sea, a secondary low will develop southwest of Ireland on Wednesday night, moving east-northeast. This system will track over Germany on Thursday and continue northeast, lingering over the central Baltic Sea on Friday and Saturday. By Sunday, the low is expected to gradually shift southwest and weaken as it moves over Poland.
Figure 2: Northly/Northeasterly flow over the North Sea according to ECMWF weather model on Thursday, 9 January at 15UTC.
At the same time, a mobile high-pressure ridge will move eastward across the United Kingdom later on Thursday. The ridge will then split into two weaker highs: one over southern Norway and the other over western Europe. The high over western Europe will gradually dissipate by late Friday, while the high over southern Norway will remain mostly stationary, extending a ridge over the North Sea throughout the weekend.
It's important to note that, between the two systems mentioned above - the low-pressure system over Germany and the mobile ridge approaching from the west - relatively strong northwesterly flow will develop over the North Sea on Thursday (see Figure 2). However, as high pressure begins to dominate, calmer conditions are expected over the North Sea from Friday onward. By Sunday, a low-pressure system northeast of Iceland is expected, with an associated frontal trough impacting the northern part of the North Sea at the same time.
In summary, low pressure will dominate the North Sea at the beginning of the second week of 2025, leading to unsettled conditions initially. However, by the weekend, high pressure will take over, bringing calm weather across most of the North Sea, making conditions favorable for offshore operations.
