Tuesday evening, Invest 96E was classified as Tropical Depression Six-E over the Eastern Pacific. Today, Six-E strengthened into Tropical Storm Fernanda, the sixth named storm of the 2017 Pacific hurricane season.  The average formation date of the sixth named storm in the Eastern Pacific is July 30, which means that the start of the 2017 season has been above average. Fernanda is likely to become a hurricane over the open Pacific waters by this weekend as it continues on a mostly westward path.

Forecast for Fernanda

As of 3:00 p.m. MDT (5:00 p.m. EDT) Wednesday, Tropical Storm Fernanda was centered near 11.8°N 112.2°W and was moving westward at about 9 mph. Maximum sustained winds were estimated at 35 knots (40 mph), with an estimated minimum pressure of 1005 mb. Fernanda is currently in an environment of wind shear of about 10 knots, and the circulation center is on the northeastern edge of the deep convection. Intensification should be slow for the next 12 hours or so. After that time, wind shear is expected to drop slightly, and remain low throughout the forecast period. Sea surface temperatures are also warm, around 28-29°C (82.4-84.2°F), which favors strengthening. In addition, relative humidity values are expected to be above 70 percent for the next three to four days. All of these factors should allow at least steady strengthening throughout the forecast period, and the National Hurricane Center (NHC) expects Fernanda to peak as a strong category 2 hurricane. However, I would not be surprised if Fernanda strengthens into a category 3 or 4 hurricane, due to the very favorable conditions. NHC also noted the possibility of rapid intensification. By Day 5-6, sea surface temperatures decrease slightly and the environment is expected to become drier, and a slow weakening trend is likely to begin shortly thereafter.

Global models continue to indicate that Fernanda is likely to be in the vicinity of the Hawaiian Islands in about ten days, possibly as a tropical cyclone. Hawaii should monitor the development of Fernanda. However, usually increasing wind shear, cooler sea surface temperatures and drier, more stable air limit strong hurricanes from making landfall in the Hawaiian Islands. When Fernanda emerges into the Central Pacific basin, the NHC will terminate advisories and the Hawaii-based Central Pacific Hurricane Center (CPHC) will take over advisories.

Aside from Fernanda, deep convection associated with what was formerly Eugene has dissipated, and is now a remnant low. Another area of low pressure in the Eastern Pacific is likely to form south of Mexico this weekend, and the NHC gives this system a near zero percent chance of development within 48 hours and a 20 percent chance within five days. The tropical Atlantic looks very quiet for the next week at least. I will be back tomorrow for an update on Fernanda, and I will also take a look at the conditions in the Atlantic.