While we’re looking at our own wintry weather later this week, a separate weather system is about to bring some very disruptive winter weather on the other side of the Atlantic.
A low pressure system, which is due to bring the severe conditions to the U.S.A., is currently developing over the southeastern United States. It is expected to deepen very quickly later today. All the ingredients are there: firstly, as it starts to move out over the Atlantic, it taps into the energy provided by warm waters of the Gulf Stream. Secondly, its position relative to the strong jet stream is just right to ensure a rapid development. And thirdly, as it develops, it pulls intensely cold air from Canada into its circulation, which turns much of the rain to snow.
So by Tuesday morning we are expecting an intense depression to be centred off coastal Maine, bringing a combination of hazards. In some areas, especially towards the south and near coasts, heavy rainfall could be an issue but for most places it’s going to be the combination of heavy snow and severe gales which lead to truly atrocious conditions – indeed the word “historic” figures in quite a lot of the American press today.
Blizzards are likely to affect many of the northeastern States from Pennsylvania (Philadelphia) up to Maine and crossing over the border into Canada, with major disruption expected for some communities, including potentially larger cities such as New York and Boston.
As well as posing a major hazard for the road network, impacts on air travel are already starting and are only likely to increase, with knock-on effects for areas quite remote from the weather, including some of the European hubs.
The worst of this particular severe weather should be over by Wednesday but the rest of the week stays very cold in the US, with the risk of renewed snowfall later.