I thought that I would take a quick look back at the cold spell that started shortly after Christmas and lasted into the first two weeks of February using reanalysis temperature anomalies. It’s quite amazing how quickly the cold and warm surges come and go across western Europe. For at least five of the eight weeks there has been an intense cold pool across southern Norway, but on the face of it that in the end wasn’t the source of the cold air in the second week of February. What is amazing is how quickly the very cold conditions in the second week across the southeast turned into very mild during the third week. Here’s the thermogram for Wattisham to show just what happened.