Winter Road Retrospective Report 2018/19: How Did We Do?
The amount of effort a winter road maintenance service needs to exert is naturally dependant on the weather conditions themselves, but also on the accuracy of weather information services they consult to plan their activities.
The Winter Roads Retrospective Report 2018/19 evaluates the weather conditions and forecast performance experienced in different locations around Europe and, for the first time, also includes North America.
The winter of 2018/19 shows how different the weather conditions can be around the globe, during the same period. While Canada and the USA were suffering under extreme cold in many regions, temperatures in Europe were mainly above average.
Whatever the specific weather conditions were, our customers also benefited in that winter from excellent forecast quality, delivered through our meteorological experts in the different weather rooms. In many cases, our hit rate for the prediction of the minimum road surface temperature was well above 90%.
Weather Conditions During the 2018/2019 Winter Season
Winter in the Northern Hemisphere runs from December through February – unless you are forecasting its weather. To monitor and warn customers of hazardous wintry weather the season is extended in both directions to include at least November and March. For the colder regions under, October and April are also included.
Despite some concerns about the possible cold impacts of a Sudden Stratospheric Warming event, the November 2018 to March 2019 period was warmer than the climate average across most of the Northern Hemisphere, with the highest anomaly seen in Europe’s February temperatures. January 2019 stood out as slightly colder than average over a significant portion of Europe and North America, and the most difficult for winter maintenance in Europe because of abundant snowfall in western countries.
Surface air temperature anomalies summary
Europe had a positive temperature anomaly through November, December, February and March, with exceptions for eastern Europe in November and December. Northern parts of the continent also bucked the trend, with cold anomalies in February and March.
January was generally close to or just below average in Europe, with some extremes like night-time temperatures below -30° C in Sweden for nine nights in a row.
Temperature anomalies were highly variable across Canada: Except for March, in the central and eastern part of the country, it was colder than average and extremely cold in February (which happened to be Europe’s warmest month!). Western regions, especially British Columbia, experienced milder than usual conditions before New Year before cooling below average for the first months of 2019.
Unlike most of Northern Hemisphere, much of the US was also colder than average in November, February, and March. Aside from some regional exceptions, such as warmth in California during November and a frequent warm anomaly in the Southeast, which very occasionally surged northwards – but this brought freezing rain and ice storm hazards to some central and north-eastern regions.
The most challenging conditions are often associated with mixed precipitation, including freezing rain. Some spectacular examples of these phenomena were observed as early as November in Poland and the USA, in mid-December in the UK and at the end of January in Switzerland. In January we dealt with significant amounts of snow in the Alps, the Sudetes and Tatra mountains, and over a large part of western Europe during the last days of January and the very beginning of February, while not forgetting the UK and northern Spain. Switzerland saw further snow right into early April.
Stormy conditions occurred several times and caused costly damage totalling several billion Euro. In total, 23 storms reached gusts of at least 97 km/h and up to 189 km/h. The strongest gales have been observed in connection with Leslie and Adrian in November, Diana in December, and Helena in February.
To find out more, download the "Winter 2018 - 19 End of Season Report for Europe and North America". It covers the weather conditions experienced during the season, the forecast performance, and how the experts help support winter maintenance teams.