Scandinavia is due to experience a cold spell this week, due to the current position of the polar jet stream to the south, combined with an area of high pressure becoming more dominant. This will allow colder polar air to flow southwards into the region, with temperatures plummeting to up to 20C below the seasonal norm from Tuesday onwards. Wednesday and Thursday are likely to be the coldest days, with temperatures forecast to fall below -20C in parts of central Sweden and Norway overnight. The low temperatures are expected to persist through the weekend and possibly into next week. However, there will be a shift to more unsettled weather from Friday, with lower pressure moving in from the west, thus creating the potential for significant snowfall over the weekend. In contrast, parts of South America have once again seen some unusually high temperatures in the past few days. Bolivia, Brazil and Paraguay have been particularly badly affected, with daytime temperatures peaking at over 40C in places, more than 10 degrees above the seasonal average. A variety of heat warnings have been issued by the respective national meteorological organisations, most of which extend to 12 November. But some areas are warning that the heat could last through to 15 November with further extensions not yet ruled out. This is the eighth heatwave Brazil has experienced in 2023, with this event expected to have greater consequences than those seen in August, September and October of this year. El Niño has been suggested as a possible catalyst for the warmer conditions here, given that warmer Pacific Ocean waters can inhibit cold fronts from reaching the region. Meanwhile, in the south Pacific, a tropical depression to the east of the Solomon Islands is strengthening as it moves south-east towards Fiji. This is expected to reach tropical cyclone intensity by late on Monday, at which point it will likely be named as Cyclone Mal by the Fiji meteorological service. The storm is forecast to track to the south-west of Viti Levu, Fiji’s largest island, which is home to about 70% of the population. Gale and storm force wind warnings have been issued, valid through to Wednesday daytime. High amounts of precipitation are also likely, with 100-200mm possible in western Viti Levu over the course of the storm.