The 2017 Atlantic hurricane season, so far, has been full of surprises and it managed to pull off another one. On Saturday morning, Ophelia strengthened into a category 3 major hurricane located south-southeast of the Azores. This makes Ophelia the sixth major hurricane of this hyperactive 2017 Atlantic hurricane season (the most since 2005), and the easternmost (but not the northernmost) Atlantic major hurricane on record. Only nine Atlantic hurricane seasons have featured as many or more major hurricanes than 2017.

As of 11:00 a.m. EDT Saturday, Ophelia was centered near 34.8°N 26.6°W, and was moving northeastward at about 25 mph. Maximum sustained winds were 100 knots (115 mph), with an estimated minimum pressure of 960 mb. Although Ophelia is located over cool sea surface temperatures of about 25°C (77°F), low wind shear, baroclinic influences, and very cool upper-level temperatures likely were responsible for Ophelia strengthening into a major hurricane. Some slight additional intensification is possible today. However, on Sunday, Ophelia is expected to transition into an extratropical cyclone and weaken slowly as it moves into cooler waters and wind shear increases quickly. Ophelia is likely going to pass over Ireland as a hurricane-force extratropical cyclone on Monday, before moving towards Scotland on Tuesday as a weakening extratropical cyclone. Ophelia is not expected to be a tropical cyclone when it nears the British Isles, however, heavy rains and strong winds are likely, especially in Ireland and Scotland.

Invests 92L in the Atlantic and 91E in the East Pacific may develop

Aside from Ophelia, there are two other disturbances that could develop into tropical cyclones. The first, Invest 92L in the Atlantic, is given a 10 percent chance of development within 48 hours and a 40 percent chance within five days by the National Hurricane Center (NHC). As of 12:00 UTC Saturday, Invest 92L was centered near 17.6°N 60.9°W. Maximum sustained winds were 30 knots (35 mph), with an estimated minimum pressure of 1007 mb. 92L is producing winds to just under tropical storm force, but development seems fairly unlikely due to strong wind shear, especially in the short term. Global models do not show much, if any, development with 92L, likely as a result of the strong shear. Residents of Bermuda should monitor the progress of 92L. The next name on the Atlantic naming list is Philippe. If the name Philippe is reached, 2017 will become the first Atlantic season since 2012 to reach the “P” named storm.

In the Eastern Pacific, Invest 91E has a high chance of developing into a tropical cyclone, but poses no threat to land. The NHC gives 91E a 70 percent chance of development within 48 hours, and an 80 percent chance within five days. As of 12:00 UTC Saturday, Invest 91E was centered near 13.2°N 112.7°W. Maximum sustained winds were 25 knots (30 mph), with an estimated minimum pressure of 1007 mb. The ECMWF and GFS models, however, show only slight development, so it is unlikely that 91E will become a hurricane. The next name on the East Pacific naming list is Selma.

I will be back with another post tomorrow.