Over the open eastern Pacific, Hurricane Fabio is likely peaking in intensity as a high-end Category 2 hurricane. A weakening trend is likely to commence for Fabio on Wednesday. The quiet period over the Atlantic basin is likely to end, with two disturbances with a chance of development over the next five days. The first, an area of disturbed weather near Bermuda, could gradually acquire some tropical characteristics later this week over the subtropical western Atlantic. The second – a strong tropical wave located southwest of the Cabo Verde Islands (designated Invest 95L), has a window to develop into a weak, short-lived tropical cyclone before conditions become less favorable this weekend.

As of 2:00 p.m. EDT (5:00 p.m. EDT) Tuesday, Hurricane Fabio was centered near 15.8°N 116.5°W, and was moving west-northwestward at about 15 mph. Maximum sustained winds were 95 knots (110 mph), with an estimated minimum pressure of 964 mb. This makes Fabio a Category 2 hurricane, and just below major hurricane status. Fabio is likely at its peak intensity, since the storm will be moving over cooler waters soon and convective cloud tops have begun to warm during the past couple hours. Although wind shear is expected to remain light, Fabio is expected to cross the 26°C (78.8°F) isotherm tomorrow, and this should gradually degrade the storm’s deep convection. Fabio is likely to degenerate into a post-tropical remnant low on Saturday, if not sooner. Fabio continues to pose no threat to land. After Fabio, the National Hurricane Center (NHC) does not anticipate any additional development over the eastern Pacific basin over the next five days.

First African tropical wave of year to be marked on the Tropical Weather Outlook may develop

The first “Invest” over the Atlantic Main Development Region (MDR) has been designated by the NHC. Invest 95L is given a 20 percent chance of development, both within 48 hours and five days. It is unknown why NHC designated the tropical wave Invest 95L, because the next number should be 92L. As of 00:00 UTC Wednesday, Invest 95L was located near 9.3°N 32.0°W, and was moving generally westward. Maximum sustained winds were 25 knots (30 mph), with an estimated minimum pressure of 1010 mb. The 18z Tuesday GFS model run predicted development of 95L into a tropical storm, though the 12z Tuesday UKMET, ECMWF and CMC models showed little to no development. Sea surface temperatures are only marginally warm, at around 26°C (78.8°F). Wind shear is expected to remain low (less than 10 knots) for the next 72 hours or so, but is expected to quickly increase to above 25 knots (30 mph) as 95L approaches the Lesser Antilles. Dry air intrusion from the Saharan Air Layer (SAL) may also limit development. I highly doubt 95L will become anything more than a weak tropical storm at the most, and it is unlikely to be a tropical cyclone when it approaches the Caribbean. It is somewhat surprising that we may have a tropical cyclone form in the deep tropical Atlantic this early this season, since the region is significantly cooler than normal.

Farther west in the Atlantic, an area of disturbed weather, producing disorganized showers and thunderstorms, is located southeast of Bermuda. NHC gives this system a 20 percent chance of development within 48 hours, and a 50 percent chance within five days. Global models do not predict much development with this system, but environmental conditions are expected to become more conducive for development late this week.

I will be back with another post tomorrow.