The National Hurricane Center (NHC) issued their first tropical cyclone advisory of 2018 Thursday afternoon, with the initiation of advisories on Tropical Depression One-E over the Eastern Pacific. Invest 90E, which remained poorly organized on Wednesday, became better organized Thursday with the formation of a sufficiently well defined circulation to be classified as a tropical depression. One-E is not expected to become a named tropical storm, and is likely to degenerate into a remnant low by late Friday. One-E is no threat to any land areas.

As of 2:00 PM PDT (5:00 PM EDT) Thursday, Tropical Depression One-E was centered near 12.4°N 126.5°W, and was moving west-northwestward at only 5 mph. Maximum sustained winds were 30 knots (35 mph), with an estimated minimum pressure of 1007 mb. One-E is not particularly well organized at the moment, with a cluster of deep convection to the east of the circulation center. One-E is currently located over a marginally favorable environment, with wind shear about 20 knots, sea surface  temperatures just above 27°C (80.6°F), and mid-level relative humidity values of about 65 percent. Wind shear is expected to increase to over 40 knots by Friday afternoon, and this should lead to the demise of One-E by late Friday, if not sooner. In addition, One-E is expected to cross the 26°C (78.8°F) isotherm late Friday, which should limit the development of deep convection after that time.

This makes 2018 the third year in a row that a tropical cyclone formed in the eastern or central Pacific before the season officially begins. The 2018 Pacific hurricane season does not officially begin until May 15, with the exception of the central Pacific, where the season does not officially begin until June 1.

Although One-E is not likely to become a named storm, it certainly cannot be ruled out, because of its somewhat unexpected formation in a fairly unfavorable environment. In the unlikely scenario where One-E acquires maximum 1-sustained winds of at least 39 mph, it would be named Aletta.

I will be back with another blog tomorrow.