Late winter and early spring are to see colder than average weather across the UK and in parts of western Europe and Norway, while the rest of Europe will see above-normal temperatures, Weather Services International (WSI) said on Monday.

The first half of winter has clearly been much milder than the last couple of winters, as a very strong polar vortex has controlled the pattern, and shielded Europe from any sustained cold. Recently, the vortex has weakened, WSI said, adding that this would allow seasonably cold weather across much of Europe in February.

This North Atlantic blocking, otherwise known as the negative phase of the North Atlantic Oscillation (NAO), will allow a return to, at least, seasonably cold weather across much of Europe in February, said WSI Chief Meteorologist Todd Crawford.

But WSI said that temperatures would only be slightly below normal, and that it would only affect the UK, Norway, and western parts of France, the Iberian peninsula, and the Benelux region (Belgium, Netherlands and Luxembourg).

Beyond that, we generally expect the negative NAO to be in control during the spring, with below-normal temperatures expected across the Nordic Region and parts of northern mainland Europe, Crawford said.

U.S.-based WSI is a weather forecast service specialised for use in the energy and aviation markets.

FEBRUARY:

Nordic Region - Warmer in Sweden/Finland, cool Norway

UK - Colder than normal

Northern Mainland - Warmer than normal, except Benelux

Southern Mainland - Warmer, except France/Iberia

MARCH:

Nordic Region - Warmer than normal

UK - Warmer than normal

Northern Mainland - Warmer than normal

Southern Mainland - Warmer than normal, except Iberia

APRIL:

Nordic Region - Warmer than normal

UK - Colder than normal

Northern Mainland - Warmer, except France/Benelux

South Mainland - Warmer than normal, except Iberia

WSI, is to publish its next seasonal outlook on 20 February.

(Reporting by Henning Gloystein; editing by Keiron Henderson)