While the remnants of hurricanes occasionally affect the British Isles, Hurricane Ophelia is going to be much stronger than the average United Kingdom (U.K.) storm. As of early this Sunday morning, Ophelia, still a category 2 hurricane (Saffir-Simpson Hurricane Scale), was forecast to become extra-tropical before land-falling in Ireland on Monday. Still, Ophelia, with a large storm force wind field (winds 39 to 73 miles per hour), will affect much of the U.K. and Ireland during the next two days, regardless of its actual path (Fig. 1). In fact, strong winds and heavy rains will be arriving well in advance of the storm.
Ophelia remains a well-formed hurricane (Fig 2), even though it is over fairly chilly northeast Atlantic waters. Its interaction with an approaching upper level trough from the west and the trough’s associated strong upper-level jet stream winds are both helping to accelerate the storm to the northeast (moving at 35 miles per hour) and transform it to an extra-tropical storm. Extra-tropical storms can have hurricane-force winds, but lack a warm central region and an eye wall with concentrated high-speed winds. Instead, extra-tropical storms (such as winter storms) have larger regions covered by high winds.
Ophelia is likely to cause considerable tree damage and produce widespread power outages, especially near and just to the east of the storm’s center. Storm surge and pounding waves can be expected along south-facing coasts (ahead of the storm) and west-facing Atlantic coasts (in the wake of the storm). Much of the U.K. will see lesser effects of the storm.
© 2017 H. Michael Mogil
Originally posted 10/15/17
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