Weather tracker: Pacific hosts two hurricanes and a typhoon
The Pacific Ocean has become a theatre of dynamic meteorological activity this week, showcasing two hurricanes in the north-east, and a typhoon in the north-west. Hurricane Gilma underwent rapid intensification into a powerful category 4 storm on Sunday as it tracked west through the Pacific. Fortunately, Gilma’s path was spared significant damage, but instead generated turbulent sea conditions over the weekend; 3.5-metre-high swells and sustained winds reaching 130mph made it a feature to be avoided by marine vessels. Gilma will eventually approach the Hawaiian archipelago, with models suggesting it will pass to the north of the islands by Friday. By then, however, Gilma is expected to have dissipated into a remnant area of low pressure with little destruction in its path.
In contrast, Hurricane Hone made its presence felt on the Hawaiian islands this weekend, passing just 50 nautical miles south of Hawai’i – the Big Island – with sustained winds towards the centre nearing 80mph on Sunday. Despite being classified as a category 1 hurricane, Hone has made a significant impact through elevated surf and sea swells, causing strong breaking waves of up to 4.3 metres, as well as strong winds gusting around 60mph. However, the biggest threat is that of flash flooding and landslides on steep slopes, especially on the eastern windward side of the island.
Weather stations on the eastern side of the Big Island reported 110mm of rainfall within six hours from 9pm on Saturday. Many stations recorded around 250mm within the first 24 hours of the onset of the rain, and one station in Mountain View, situated on the windward side of the island, recorded 350mm – nearly three times the average monthly precipitation for August. The effects of Hone should ease on Monday as it continues its westward journey.
As the two hurricanes churn in the north-eastern Pacific, Typhoon Shanshan is encroaching on southern Japan in the north-west. On Sunday, sustained wind speeds were recorded at 75mph, and were accompanied by gusts reaching approximately 110mph. The storm is anticipated to strengthen further as it nears landfall, with projections indicating it will attain very strong typhoon status by Tuesday. To be classified as such, sustained winds must exceed 97mph, and forecasts suggest Shanshan could reach maximum speeds of 125mph.
The destructive potential of these winds poses a significant threat to infrastructure as the typhoon traverses Japan during the middle of this week. However, the associated rain is equally concerning, with some meteorological models predicting that more than 300mm could fall within 24 hours around Thursday. This deluge raises the risk of flash flooding and heightens the potential for landslides, particularly in mountainous regions.
