European weather outlook until April 2025

The European weather trend into early spring 2025

Although a stubborn high-pressure pattern will continue to have some influence over parts of eastern, south-eastern Europe, along with a cold spell, including across Turkey and the Black Sea region firstly, a more active Atlantic pattern starts to develop from the west.

Consistent with this, the North Atlantic Oscillation (NAO) is trending stronger positive, with a renewed risk of passing intense low-pressure systems causing heavy rainfall, strong winds and possibly leading to disruptive weather, especially in Northwest Europe, Great Britain and Ireland, and parts of Western and Northern Europe.

The stratospheric polar vortex (SPV) is strengthening again after temporarily dropping to near-normal levels. Because there is a persistent and strong low-pressure signal between Iceland and Greenland (as feedback from a strong SPV), the probability of stronger downstream high-pressure ridging remains.

A vivid way to visualize dominant weather regimes is the weather regime frequency forecast (W.R.F.). The latest ECMWF weather regime ensemble forecast (see below) shows a European high-pressure regime at first. It also indicates a recurring and stronger positive NAO background flow starting soon.

The main frontal zone should move further north or northwest than the climatological average, especially in the eastern North Atlantic-Scandinavia region. This favors a brisk and fairly mild south-westerly flow. The stronger recovery of the SPV supports a stronger positive NAO index, which is apparently returning and could even persist until around mid-March.

There is a probability of either a negative NAO or an Atlantic Ridge from the beginning of March, which could indicate a cold snap risk. For the time being, there are only vague indications.

 

What about later in March and through early April?

Above-average temperatures are expected through March, with a positive NAO regime more likely, at least at first. An active westerly jet stream could remain, albeit shifted northward of the climate mean, in line with higher pressure at mid-latitudes. Thus, there are mixed signals for positive NAO and intermittent high-pressure blocking regimes. Blocking is unlikely to materialize at high latitudes, meaning a low risk for widespread, long-lived and significant cold outbreaks until around mid-March.

However, the predicted set-up (e.g. high pressure over parts of continental Europe) could lead to cut-off low pressure systems held southwards in and around the Mediterranean and south-east Europe/Turkey. This could suppress temperature anomalies in those areas and lead to stronger winds and heavy convection-enhanced precipitation.

Things will change later in March. The expected state of the SPV plays an important role here (see the zonal mean zonal wind state at 10hPa/60N, and ECMWF’s seasonal outlook).

Apart from a postulated weakening of the SPV by early March, the SPV could remain, or recover, stronger until around mid-March or even beyond (low confidence), followed by a weaker SPV towards end-March and an earlier-than-usual final stratospheric warming possible in early April. This seems plausible given a stronger-than-usual SPV this winter.

Of course, the latter could lead to more frequent high latitude high pressure blockings in the eastern North Atlantic or Scandinavian-Ural sector, which in turn carries the risk of colder spells in other parts. In view of this, less positive temperature anomalies or even close average temperatures are likely in larger parts of Europe later in March and through April seem plausible.

The risk of high-pressure blockings increases towards the end of March and into April according to ECMWF’s W.R.F., potentially meaning drier and calmer periods across larger parts of Europe.

There is also the possibility of some late Arctic cold air outbreaks, consistent with an increasing risk of a negative NAO pattern.

Source: Copernicus Climate Change Service

The latest temperature, precipitation, and wind departure forecasts for March and April are below.

 

Bottom line

Widespread milder at first, more pronounced across northern, north-eastern and parts of eastern Europe. Wetter and windier, especially UK to Scandinavia (storm track includes passing intense LP systems with the risk of disruptive weather).

Later in March and early April will find a drier and calmer trend with temperatures closer to average, notwithstanding the risk of late Arctic cold air outbreaks.

About the author

Dr. Jens Bonewitz

Dr. Jens Bonewitz is an experienced long-range energy meteorologist at DTN. He consults with utility and renewable energy clients to help plan and prepare for the impact of weather. He combines research and its practical applications to produce meaningful weather forecasts within the S2S range.