Heavy snow fell in parts of New England this week. New York’s Central Park received a few centimetres of snow, while 21cm (8.5in) was dumped in parts of Long Island. This is the earliest New York has experienced snowfall since 2018.
New York narrowly missed out on widespread snowfall a few weeks ago. The low-pressure system tracked ever so slightly to the north of New York, enabling the warmer air to edge in. Meanwhile, upstate New York and other parts of New England were on the colder side of the system and received significant snow accumulations.
This week, however, the synoptic picture was different. Bitterly cold air plunged down from Canada into the north-east of the US. In tandem with the cold air, a low-pressure system began to track eastwards. As the cold air was already embedded over New York, any precipitation that fell was snow.
Southern Spain was hit by Storm Emilia this week. In the early hours of Tuesday morning, a tornado, along with heavy rain, wreaked havoc in the seaside town of La Cala de Mijas, Málaga. The tornado swept through the town, tearing down the £67,000 Christmas lights along the main high street. It is estimated the storm caused £500,000 in damages.
Rain falls in Málaga, Spain. Photograph: Lorenzo Carnero/Zuma Press Wire/Shutterstock
The tornado formed as warm, less dense, moist air rose, while colder, drier air sank. A process known as “wind shear” allowed winds at different altitudes, blowing at different speeds and directions to create an invisible horizontal tube of rotating air. An updraft, created by the rising moist air, lifted this tube of air and shifted its orientation vertically. This forms a “mesocyclone”, a rotating column of air within a storm. Cold, sinking air facilitated downdrafts which wrapped around the mesocyclone, causing it to intensify and focus the rotation downward, providing the perfect conditions for localised wind gusts to reach 80mph (130km/h). Outside the tornado column, winds were strong but not of debris-shifting strength, highlighting the hyper-localised nature of this phenomenon.
