Invest 94L – a broad area of low pressure located about 650 miles southwest of the Cabo Verde Islands – is likely to develop into a tropical cyclone later this week as it moves west-northwestward across the tropical Atlantic at about 5-10 mph. In the Eastern Pacific, three systems (including Invest 94E) have a chance of development this week as well. In the West Pacific, Severe Tropical Storm Nanmadol could pose a threat to Japan tomorrow.

Invest 94L: Likely to Develop, could be near Leeward Islands by this weekend

Invest 94L in the central tropical Atlantic is gradually becoming better organized. In their 8:00 p.m. EDT Tropical Weather Outlook, the National Hurricane Center (NHC) gave this system a 40 percent chance of development within 48 hours and a 70 percent chance of development within five days. Model support for the development of 94L is high, with nearly all reliable models – including ECMWF, UKMET and GFS – predicting the development of a tropical depression within 48 hours. Because model support is so strong, I believe that NHC’s chances are too low, and I give 94L a 60 percent chance of development within 48 hours and an 80 percent chance within five days. 94L is likely to develop into a weak to moderate tropical storm before weakening near the Lesser Antilles due to increasing wind shear. A strong subtropical ridge is likely to push 94L on a west-northwestward path, but a weakness in the ridge could cause 94L to begin to recurve to the northeast without reaching the United States. The track and intensity of 94L is highly uncertain as of this time, and residents in the Lesser Antilles, Puerto Rico, Bahamas, and Southeastern United States should monitor the development of this system. A hurricane in the long range cannot be ruled out, but it is not a likely scenario as of this time.

As of 00:00 UTC Tuesday, Invest 94L was centered near 8.8N 33.2W and was nearly stationary. Maximum sustained winds were estimated to be 25 knots (30 mph) with a minimum pressure of 1011 mb.

Invest 94E and two other systems could develop in East Pacific

The East Pacific has not one, not two, but three areas that could develop into tropical cyclones during the next five days. One of them – Invest 94E – is given a 60 percent chance of development within both 48 hours and five days by the NHC. 94E is likely to develop into a tropical depression soon before encountering cooler water later this week. As of 00:00 UTC Tuesday, Invest 94E was centered near 13.9N 111.0W, and was moving west-northwestward. Maximum sustained winds were estimated at 25 knots (30 mph) with a minimum pressure of 1009 mb.

In addition to 94E, two other areas of disturbed weather in the East Pacific have chances to develop into tropical cyclones. A tropical wave located  south-southwest of the Gulf of Tehuantepec is given a near zero percent chance of development within 48 hours and a 70 percent chance of development within five days. In addition, a third area of disturbed weather is located in the far Eastern Pacific and is given a near zero percent chance of development within 48 hours, and a 20 percent chance within five days. It seems very likely that the East Pacific will get active soon, as is typical for early July. The next three names on the East Pacific naming list are Eugene, Fernanda and Greg.

Tropical Storm Nanmadol near southern Japan, should turn post-tropical soon

Tropical Storm Nanmadol in the Western Pacific peaked near typhoon intensity early Monday morning with maximum 10-minute sustained winds of 55 knots (65 mph) and maximum 1-minute sustained winds of 60 knots (70 mph). The estimated minimum pressure at peak was 985 mb. This makes Nanmadol the strongest storm so far of the somewhat quiet 2017 Pacific typhoon season. Nanmadol is likely to continue on a northeastward path and could bring some rain and high winds to southern Japan. Nanmadol should transition into a post-tropical cyclone soon before dissipating later this week. Nanmadol has weakened this evening, with maximum 1-minute sustained winds now estimated at 40 knots (45 mph), with the cyclone centered near 32.8N 130.3E.

I will be back tomorrow for another post on these systems. The tropics are getting very active!