A 15-hour weather warning has been issued for Devon and Cornwall due to heavy rain, starting at 18:00 BST on Friday, April 18, 2025, and lasting until 09:00 on Saturday, April 19, 2025. The Met Office has warned of a "prolonged spell of rain" moving across the two counties, with forecasts indicating that up to 75mm (2.95 inches) of rain could fall, particularly around the Dartmoor area. Additionally, conditions are expected to be "quite windy," heightening concerns about flooding and other disruptions.
According to the Met Office, flooding, power supply interruptions, and public transport disruptions are anticipated across the warning area, which encompasses most of Cornwall and parts of south, central, west, and east Devon. The forecasters stated, "Rain developing early Friday becomes heavier and more persistent later on Friday and persists into Saturday before easing from Saturday late morning." Residents are advised to remain vigilant as the inclement weather approaches.
In New Zealand, Cyclone Tam has caused significant disruptions, especially in Northland, where thousands remain without power due to the storm's aftermath. Restoration of electricity services may take two to three days, as crews work to clear debris and restore power. The cyclone has directed unstable fronts and troughs onto the country, leading to fresh weather warnings from MetService.
As the cyclone continues to impact New Zealand, forecasters are monitoring a potential second weather system forming over the Tasman Sea. MetService reported a moderate risk of thunderstorms over the upper North Island on April 18, 2025, with localised heavy rain expected. "This afternoon and evening, the risk of thunderstorms increases to moderate for northern Northland and Bay of Plenty from Rotorua eastwards," MetService stated. Heavy rainfall intensities of 10 to 25mm per hour are predicted, with a low risk of downpours reaching 25 to 40mm per hour in some areas.
In the Coromandel region, residents are no longer isolated after Cyclone Tam caused flooding and slips on key routes, which had previously cut off access to several townships. State Highway 25 was closed overnight due to rising waters, but has since reopened, although caution is still advised due to residual surface water on the roads. The NZ Transport Agency (NZTA) confirmed that crews are working diligently to clear any remaining slips.
As the storm's effects continue, the forecast indicates that the weather will gradually improve. However, the remnants of Cyclone Tam are expected to linger, bringing muggy conditions and potential record-breaking temperatures across the country. MetService has predicted daytime highs in the mid to high 20s for Saturday and Sunday, particularly in the eastern and lower North Island.
Looking ahead, meteorologists are keeping a close eye on a second weather system that could develop in the tropics. MetService meteorologist Mmathapelo Makgabutlane explained, "With the low-pressure system itself, the real key will be where it forms and that will determine how deep it becomes once it forms." Although the chances of this system developing into another tropical cyclone are low, it remains a possibility as the cyclone season is still active.
As Cyclone Tam weakens, the MetService has updated its warnings and watches, lifting alerts for Northland and Auckland while issuing more severe warnings for areas in the lower North Island. Mount Taranaki and Tasman are bracing for nearly 40 hours of heavy showers, with forecasts predicting up to 200mm of rain. The heavy rain warnings for Tasman came into effect at 9am on April 18, while Taranaki's warnings will start at midnight.
In summary, the weather systems affecting both Devon and Cornwall in the UK and New Zealand's North Island are prompting significant precautions and preparations among residents and authorities. With heavy rains expected to cause potential flooding and disruptions, communities are urged to stay informed and heed any warnings issued by meteorological agencies.
