Featured Research

from universities, journals, and other organizations

European winter weather harder to forecast in certain years

Date:
May 15, 2013
Source:
National Oceanography Centre
Summary:
Weather forecasters have a tougher job predicting winter conditions over Europe in some years over others, concludes a new study.

Widespread snowfall in the UK in December 2010.
Credit: Credit NASA / Jeff Schmaltz

Weather forecasters have a tougher job predicting winter conditions over Europe in some years over others, concludes a new study carried out by the National Oceanography Centre.

The study revealed that the relationship between our winter weather and the strength of the airflow coming in from the Atlantic -- one of the factors used by forecasters to predict the weather -- is stronger in some years than others. The results were recently published in the Royal Meteorological Society publication Weather.

Co-authors Drs Joël Hirschi and Bablu Sinha from the National Oceanography Centre explain: "There are two major atmospheric pressure systems centred around Iceland and the Azores that are very influential for the weather in Europe. Air flows between these two systems, bringing mild air from the North Atlantic to Europe. The pressure difference between the two pressure systems -- and the corresponding airflow -- fluctuates and scientists call this phenomenon the 'North Atlantic Oscillation', or NAO, which is by convention positive when the pressure difference is a stronger than average and negative when it is weaker than average.

"When there is more air coming from the Atlantic, we get milder, wetter winters, as in 2007 and 2008. And when the airflow is weaker, our weather is influenced by air masses from Siberia and the Arctic, bringing colder and drier conditions."

But the scientists wanted to know how reliable the relationship is between the pressure systems over Iceland and the Azores, and European weather. The results show that when the airflow is weaker -- due to a smaller pressure difference between the two systems -- European weather is harder to predict than when it is stronger.

"It's like a guitar string," says Dr Hirschi. "When there is tension in the string, it stays straight. If you slacken the tension enough, the string goes wobbly.

"So when we have a vigorous airflow driven by a large pressure difference, it tends to stay straight and the weather is easy to define. When weaker, the airflow meanders, leading to more complicated weather patterns. You get big differences in weather over Europe, switching between cold Arctic/Siberian air masses, and milder subtropical air masses. This is why in December 2010, the UK suffered from low temperatures and heavy snowfall, while other European regions such as the Balkans experienced warm and wet conditions."

In this study, the researchers looked at the strength of the NAO during each year between 1880 and 2009 and compared this with observations of winter weather conditions over the same period.


Story Source:

The above story is based on materials provided by National Oceanography Centre. Note: Materials may be edited for content and length.


Journal Reference:

  1. Roger Heape, Joël Hirschi, Bablu Sinha. Asymmetric response of European pressure and temperature anomalies to NAO positive and NAO negative winters. Weather, 2013; 68 (3): 73 DOI: 10.1002/wea.2068

Cite This Page:

National Oceanography Centre. "European winter weather harder to forecast in certain years." ScienceDaily. ScienceDaily, 15 May 2013. <www.sciencedaily.com/releases/2013/05/130515085226.htm>.
National Oceanography Centre. (2013, May 15). European winter weather harder to forecast in certain years. ScienceDaily. Retrieved August 31, 2014 from www.sciencedaily.com/releases/2013/05/130515085226.htm
National Oceanography Centre. "European winter weather harder to forecast in certain years." ScienceDaily. www.sciencedaily.com/releases/2013/05/130515085226.htm (accessed August 31, 2014).

Share This




More Earth & Climate News

Sunday, August 31, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: Volcano Erupts on Papua New Guinea

Raw: Volcano Erupts on Papua New Guinea

AP (Aug. 29, 2014) — Several communities were evacuated and some international flights were diverted on Friday after one of the most active volcanos in the region erupts. (Aug. 29) Video provided by AP
Powered by NewsLook.com
Raw: Small Volcanic Eruption in Iceland

Raw: Small Volcanic Eruption in Iceland

AP (Aug. 29, 2014) — Icelandic authorities briefly raised the aviation warning code to red on Friday during a small eruption at the Holuhraun lava field in the Bardabunga volcano system. (Aug. 29) Video provided by AP
Powered by NewsLook.com
As Drought Continues LA "water Police" Fight Waste

As Drought Continues LA "water Police" Fight Waste

AFP (Aug. 29, 2014) — In the midst of a historic drought, Los Angeles is increasing efforts to go after people who waste water. Five water conservation "cops" drive around the city every day educating homeowners about the drought. Duration: 02:17 Video provided by AFP
Powered by NewsLook.com
Killer Amoeba Found in Louisiana Water System

Killer Amoeba Found in Louisiana Water System

AP (Aug. 28, 2014) — State health officials say testing has confirmed the presence of a killer amoeba in a water system serving three St. John the Baptist Parish towns. (Aug. 28) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins