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No doubt with time joining the ranks of retired ‘M’ hurricanes Mitch, Matthew, Maria and last season’s Milton, Major Hurricane Melissa set numerous records on its way to becoming probably the most devastating tropical cyclone to have ever impacted the west of Jamaica. Melissa began life as a westward propagating African Easterly Wave, as many of these systems do, quickly moving into the Caribbean Sea late on 19 October (all dates/times utc), and became a tropical storm by 21 October, south of Haiti and the Dominican Republic. It was at this point Melissa slowed and began a northward turn towards Jamaica. Initially, in the presence of strong westerly shear, Melissa struggled to get organised, and its centre began to move erratically, relocating eastwards several times. Ensemble graphics at the time exhibited exceptionally large spread, given weak steering currents, with the additional complication that the steering flow ‘felt’ by the cyclone varied significantly depending on how vertically deep and developed the cyclone could get (a facet which is often much harder to predict in developing tropical cyclones). By 25 October, with the westerly shear relaxing, Melissa was free to take full advantage of the 30–31°C sea surface temperatures and high oceanic heat content. It resumed its journey westwards to the south of Jamaica, whilst rapidly strengthening into the third Category 5 hurricane of the 2025 Atlantic season by 27 October. 2025 is now the only season to have recorded three Category 5 hurricanes, one short of 2005’s record of four, and at least one more than any other season on record. Over the following hours, all eyes were watching the confluence of an extending upper trough dipping down from the Eastern Seaboard of the US and the westwards moving Melissa – the interaction of the two was expected to alter Melissa’s steering currents, causing it to make a sharp turn to the north-northeast. This turn did indeed occur during the early hours of 28 October, west of most expectations, but not sufficiently far west as to prevent a catastrophic impact on Jamaica becoming an inevitability. By around 1700 utc on 28 October, Melissa made landfall near New Hope, with devastating 160kn sustained winds, and a staggeringly low central pressure provisionally set at 892hPa (having reached and maintained this intensity just offshore some 2h earlier). This made it the most intense landfalling Atlantic hurricane on record, tied with the 1935 ‘Labor Day’ hurricane, and the third most intense hurricane ever observed anywhere over the Atlantic basin. Perhaps somewhat unusually, Melissa did not undergo an eyewall replacement cycle, like many strong cyclones of its type, which is one factor that allowed it to maintain such ferocity. Its peak sustained wind speeds of 160kn have only been surpassed in the Atlantic basin by Hurricane Allen in 1980. Gusts are likely to have been in excess of 200kn, and a dropsonde recorded an incredible peak wind of 219kn in Melissa’s southern eyewall, the highest such measurement ever made by a dropsonde. It is possible that Melissa also experienced a record rate of lightning flashes as observed by the NOAA’s Global Lightning Mapper, peaking at 699 flashes per minute as the cyclone approached maximum intensity, although of course the period over which these have been observed is short. It is worth noting, however, that all of these records are subject to revision as the data will be more thoroughly analysed in the National Hurricane Center’s (NHC) post-storm report. Melissa then continued northeast over the following few days across Cuba, the Bahamas and towards Bermuda, but as a steadily weakening cyclone. Impacts were felt widely across the central Caribbean, with severe flooding affecting Haiti and the Dominican Republic, leading to the loss of dozens of lives. But it was Jamaica that bore the brunt of Melissa with numerous fatalities, widespread demolition of buildings and infrastructure, accompanied by severe flooding that will take some communities months, if not years, to recover from. (Sources: NHC, Met Office, BBC News, Sky News, Yale Climate Connections, Colorado State University, Nahel Belgherze (@WxNB_ on X).) Until recently, Iceland has remained one of the few remaining mosquito-free havens on Earth. Despite its countless marshes and ponds – prime mosquito breeding grounds – the island’s cool climate has long kept the biting bugs at bay. Now, with the Arctic warming nearly four times faster than the global average, conditions are shifting. A hardy, cold-resistant mosquito species has recently been discovered in Iceland, capable of surviving winters by sheltering in basements and barns. For now, these newcomers pose little health risk as they are not known carriers of the Zika virus. Their timing, however, was less than ideal. Just days after their discovery, Iceland was blanketed by record-breaking October snow. Reykjavik saw accumulations of up to 27cm by noon on 28 October, prompting orange alerts for heavy and blowing snow in and around the capital. The last time October snowfall reached such depths in the capital was in 1921. (Sources: The Guardian, Iceland Review, RUV.) October brought a mix of extremes to the Iberian Peninsula. Storm Alice, the first named storm of southwest Europe’s season, lashed eastern Spain with torrential rain and gale-force winds. The Spanish meteorological agency, AEMET, issued red rain alerts for parts of Valencia, where up to 160mm of rain fell in just 24h. Flash flooding inundated the streets in Catalonia as well, where orange alerts were in force, sweeping away vehicles in torrents of brown, muddy water. In the Balearic Islands, operations at Ibiza airport were briefly suspended as runways flooded under relentless downpours. Yet, October was not a total washout. A late-month heatwave gripped southern Iberia, bringing record-breaking temperatures once more. Alicante recorded its warmest October night on record, with lows of 22.4°C, just topping the previous record from 2013. Daytime highs soared to 36.6°C in Manilva, Malaga, just 1.5°C shy of Spain’s all-time October record of 38.2°C in 2023. Across the border, Gibraltar sweltered too, reaching 31.0°C on 24 October, the warmest October day since 1997, with mean monthly temperatures running 2.2°C above the 1991–2020 average. (Sources: BBC News, Euronews, AEMet.) Following the Trump administration’s shutdown of Climate.gov in May 2025 (see Weather news, September 2025), which resulted in job losses and loss of public data access, the non-profit organisation Climate Central has stepped in to relaunch NOAA’s Billion-Dollar Weather and Climate Disasters database. Led by former NOAA lead scientist Adam Smith, the group aims to create a new interactive tool to help users explore historic disaster costs, with plans to expand coverage to smaller events as well. The original, archived data remain available through the National Centers for Environmental Information (NCEI) website. (Sources: Climate Central, Fox News.) High in Italy’s Dolomites, the thawing of permafrost is turning once stable peaks into ticking time bombs. Drone footage has recently revealed widening fractures where ice once bound the rock together. In the summer of 2025, nearly 100 tourists were evacuated following a series of rockfalls in the Brenta Dolomites, underscoring the growing danger. Entire summits are now destabilising as permafrost – nature’s natural glue – melts under rising temperatures. The repeated freeze–thaw cycles that follow are prying open cracks, creating wedges of space and fractures that weaken mountain faces. The result has been more frequent avalanches and landslides, not only in the northern Dolomites but also across the entire mountain range. Scientists warn this is part of a larger global change. If warming continues at its current rate, nearly 93% of the world’s near-surface permafrost could vanish by the end of this century. For the Dolomites, this could mean dramatic reshaping of their iconic mountain peaks and increasing risks for the communities and visitors who depend on them. (Source: Earth.org.) It has been a busy typhoon season in the western Pacific, with, at the time of writing, 27 systems escalating to named-storm status. According to Colorado State University, the Northwest Pacific is experiencing an active season, with several storms reaching significant intensity. Ragasa (Figure 1) arrived in September as the nineteenth named storm and the first to exceed Category 3 strength. It peaked as a Category 5-equivalent super typhoon, with sustained winds of 145kn and central pressure 905hPa. Ragasa caused widespread devastation as it crossed the Philippines and Taiwan, before slamming into southern China. As it weakened, it swept across Hong Kong and into northern Vietnam, triggering Hong Kong to raise its typhoon warning to Level 10 – the maximum level – grounding all flights for 36h. Flooding reached second-storey windows in places, and tidal surges devastated coastal communities. Hot on Ragasa’s heels, Typhoon Bualoi formed over the central Pacific and followed a similar track across the Philippines before veering towards Vietnam. Although less intense, its torrential rains compounded damage in areas already battered by earlier storms. Flooding, landslides and infrastructure damage further strained emergency services and slowed recovery. In October, Typhoon Halong also reached Category 4-equivalent status, but it was Typhoons Kalmaegi and Fung-wong that brought a fresh reminder of how late-season systems can still bring catastrophic devastation. Crossing the central Philippines as a Category 3-equivalent storm, Kalmaegi’s 80kn winds tore roofs from homes, whilst torrential rain turned roads to rivers. The flooding, described as among the worst in decades, has left at least 188 people dead in the Philippines. As Kalmaegi barrelled through central Vietnam, killing a further 5 people, Fung-wong was wreaking further havoc across the Philippines, mere days after the devastation left by Kalmaegi. Whilst long-range forecasts had suggested a ‘near-normal’ 2025 season, the impacts of Ragasa, Bualoi, Kalmaegi and Fung-wong show how averages can mask extremes. Across coastal Asia, this season has proved that ‘normal’ is never synonymous with safe. (Sources: Severe Weather, Earth Observatory, Reuters, BBC News.) Now expected to be implemented in the first quarter of 2026, the latest iteration of ECMWF’s Integrated Forecasting System will come with a number of significant changes. These will include better representation of sea ice and ocean dynamics with the introduction of the NEMO4-SI3 model, upgraded data assimilation, improvements to its ensemble stochastic perturbation scheme and better parameterisation of convection. It is this latter change that may be most evident to the majority of users; currently, convective precipitation can be seen to build up unrealistically along coastlines due to the inability of the model to advect it inland, but in Cycle 50r1, a portion of this precipitation will be treated by the cloud scheme where it can both advect and evaporate in a more realistic fashion. Another small but notable change is that the deterministic ‘HRES’ − which became identical to the ensemble control in Cycle 49r1 − will no longer be distributed and will be called ’ENS Control’ instead. For further details, see ECMWF’s Autumn 2025 newsletter1. (Source: ECMWF.)