Published March 24, 2013
March has been a wild month for weather across the United Kingdom and Ireland, departing wildly from normal.
Snowstorms, heavy rain, damaging wind and bitter cold have marked much of the winter throughout Europe, but especially the U.K., as multiple pushes of cold Arctic air have arrived in the region and brought significant departures from normal.
On the other side of the coin, the storminess responsible for the cooler temperatures has also led to well-above-normal precipitation. Rain and snow have been almost twice the normal amount for much of the U.K. and Ireland.
So why has this March been so cold and wet? The reason is a combination of two factors, according to Long-Range Team Member Meteorologist Mark Paquette.
"The first factor is a weather signal over the Atlantic, which meteorologists refer to as a 'Negative NAO.' When the NAO [North Atlantic Oscillation] signals negative, it is common for storms to reach south into both the eastern United States, as well as western Europe."
"The second factor is a second weather signal over the polar region, which meteorologists refer to as a 'Negative AO.' When the AO [Arctic Oscillation] signals negative, cold air that is usually locked up over the Arctic is allowed to spill out across the remainder of the Northern Hemisphere."
"When you put the two together, you get cold and wet weather for both western Europe and the eastern United States."
The bad news for the region will continue over the coming days. The London forecast will be at least largely dry through the coming weekend, with cold temperatures expected and not a single day even close to normal.