2015 has brought a number of weather oddities with Hurricane Fred being the latest. Is the strong El Nino the cause of all the weirdness? The Washington Post has the scoop…
Hurricane Fred, which formed over the weekend in the far eastern Atlantic, is truly one of a kind. Not only has Fred set the record for easternmost hurricane in the tropical Atlantic Ocean, it prompted the very first hurricane warning for the Cape Verde Islands and has provided the first satellite view of a hurricane in the region since weather satellites were launched into space in the early 1960s.
Hurricane Fred was born from Tropical Depression Six, which formed early Sunday morning just west of the coast of Africa. The system was quickly upgraded to Tropical Storm Fred, remarkably far east in the Atlantic. Then on Sunday night, forecasters at the National Hurricane Center saw enough strength in Fred to make it the second hurricane of the 2015 season, which also made it the easternmost hurricane formation on record in the Atlantic Ocean.
Sort of. A slight qualifier is needed: Fred now holds the record for the easternmost hurricane formation in the tropics. Looking back through the annals, just 11 hurricanes formed east of 30 degrees west, and of those, 10 were in the deep tropics (classic “Cape Verde” hurricane formations). Back in 2005, Hurricane Vince briefly reached hurricane intensity while tracking toward Portugal and was further east than Fred when it did so. It was also much farther north, and outside the tropics. These records extend back to 1851.
The other 10 storms — the classic Cape Verde hurricanes in the tropics — quickly recurved to the north, but Hurricane Fred is the first to actually pass over the Cape Verde Islands as a hurricane.
Hurricane Fred is forecast to track to the northwest. On Monday morning, Fred’s peak winds were 85 mph, estimated from satellite, and the storm was moving northwest at 12 mph.
Two more firsts from Hurricane Fred: for first time ever, the Cape Verde Islands are under a hurricane warning. It’s also the first time we have a satellite image of a hurricane over the islands. The only other time a hurricane formed over the islands was in 1892 — long before the satellite era.
Although environmental conditions favor Fred to strengthen on Monday, a combination of factors will weaken the hurricane over the next few days, including drier air, cooler water temperatures and increasing wind shear, which acts to tear tropical cyclones apart.
Hurricane Fred formed from what we call an African easterly wave — an area of low pressure that moves west off the coast of Africa in the trade winds that can serve as the seed for hurricane formation. Interestingly, for easterly waves to make the long journey across the Atlantic Ocean and become a threat to land, they must remain relatively weak at first to avoid getting steered northward through weaknesses in the vast area of high pressure that tends to dominate the Atlantic in the summer.
The current model analysis of the mid-tropospheric steering winds shows this area of high pressure — the subtropical ridge (below). The gray streamlines show the high-level winds that steer stronger storms. Weaker storms are steered by winds lower in the atmosphere, thus they are able to make it farther west toward North America.
Looking at the seasonal activity so far, Hurricane Fred is the season’s sixth named storm and formed on Aug. 30. The average date for the formation of the sixth storm is Sept. 7. The second hurricane of the 2015 season formed on Aug. 31, compared to the average of Aug. 29. While those dates look somewhat “average,” the short duration of those storms means that the total activity for the season is still well below average for this date at just around 58 percent — typical for a strong El Niño, which tends to decrease hurricane activity in the North Atlantic.
Folks in Florida are enjoying the calm weather. Let’s hope it persists!