On Saturday, the National Hurricane Center started issuing advisories on a new tropical depression that formed to the east of Florida. Early Sunday morning it was upgraded to a tropical storm, earning the name Arthur and becoming the first named storm of the season. It is headed to the north and is expected to brush North Carolina’s Outer Banks before making a sharp east turn, heading out to sea, and losing its tropical characteristics.
As of writing, portions of North Carolina’s coast are under tropical storm warnings (marked in blue on the map). Not shown on this map is that wide swaths of the Atlantic where Arthur is expected to pass over are also under a tropical storm watch. This storm is not expected to become a hurricane. At Cape Hatteras, winds are expected to reach near 50 mph with gusts around 60 to 65 mph on Monday, which is the highest wind speed currently expected to impact land.
Rainfall will arguably be a bigger player for those living in Eastern North Carolina, but because of the projected path and speed of Arthur flooding isn’t a huge concern. Many areas east of I-95 will see one to three inches of rain with isolated amounts up to five inches possible. If Arthur’s center does make landfall (which some models are showing will happen), there will also be a threat for tornadoes. The most likely place to find tornadoes in a tropical cyclone in the Northern Hemisphere is what’s called the right-front quadrant, which for this storm will be roughly the northeastern quarter, so if it doesn’t make landfall the tornado threat is significantly lower.
More interesting than this storm itself is the fact that its formation makes 2020 the sixth year in a row that has had a tropical storm form in the North Atlantic before the official start of hurricane season, which is June 1. A storm forming before June 1 isn’t all that exceptional on its own with a lengthy list on Wikipedia dedicated to the subject.
A tropical storm is defined as being a tropical cyclone with winds at or in excess of 39 mph. Cyclones with winds below 39 mph are called tropical depressions, and those with winds at or above 74 mph are called hurricanes if they occur either in the Atlantic Ocean or in the North Pacific east of the International Date Line. The last pre-season hurricane in the Atlantic was 2016’s Hurricane Alex. This storm formed in January of that year and reached Category 1 strength with 85 mph winds at its peak. Alex crossed the Azores and went on to impact Greenland after losing its tropical characteristics.
Forecast and warning information on this post are accurate as of 8pm Eastern Time on May 17. For current information, please visit the National Hurricane Center’s website.
