Special Features

Former Invest-AL93 has formed into Tropical Storm Humberto, and is centered near 20.1N 54.9W at 24/2100 UTC or about 480 nm ENE of the Northern Leeward Islands, moving WNW at 13 kt. Estimated minimum central pressure is 1008 mb. Maximum sustained wind speed is 35 kt with gusts to 45 kt. The cloud pattern of the cyclone, as seen in satellite imagery, is gradually becoming more symmetrical. In addition, numerous moderate to strong convection is increasing over the center and within 120 nm NW and 90 nm SE of the center. Scattered moderate to isolated strong convection is within 30 nm either side of a line from 17N55W to 19N53W. Humberto is forecast to maintain its present motion over the next several days with a slower forward motion. Steady strengthening is forecast during the next several days.

Please read the latest HIGH SEAS FORECAST issued by the National Hurricane Center at website - https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml and the latest Humberto NHC Forecast/Advisory and Public Advisory at www.hurricanes.gov for more details.

A tropical wave, Invest-AL94, is along 67W south of 22N. It is moving westward at about 15 kt. Satellite imagery shows that numerous moderate to strong convection south of Puerto Rico from 14N to 17N between 65W and 68W. Numerous moderate to isolated strong convection is elsewhere from 14N to 19N between 63W and 69W. An area of numerous moderate to isolated strong convection is north-northeast of Puerto Rico and Virgin Islands from 18N to 22N between 60W and 67W. The observed convection has become better organized since yesterday. This wave is expected to move west-northwestward spreading heavy rainfall and gusty winds across Puerto Rico and the Dominican Republic through early tomorrow. The system is then expected to slow down and turn northwestward when it reaches the southwestern Atlantic. A tropical depression is likely to form when the disturbance is in the vicinity of the Bahamas late this week. Interests in Puerto Rico, the Dominican Republic, the Turks and Caicos Islands, and the Bahamas should monitor the progress of this system. The wave has a medium chance of a becoming a tropical cyclone during the next 48 hours. Please refer to he latest Tropical Weather Outlook issued by the National Hurricane Center at website: www.hurricanes.gov for more information.

Tropical Waves

A central Atlantic tropical wave has its axis near 41W from 02N to 15N, moving westward at 10 to 15 kt. Scattered moderate convection is within 120 nm either side of the wave from 07N to 10N.

Monsoon Trough/ITCZ

The monsoon trough axis enters the Atlantic along the coast of Africa near 16N17W, and extends southwestward to 09N32W, where it transitions to the ITCZ to 07N39W. It continues from 07N43W to 06N54W. Aside from convection related to the tropical wave near 42W, scattered moderate convection is within 60 nm either side of the ITCZ between 43W and 48W.

Gulf Of America

A broad upper-level trough extends southwestward from the southeastern U.S. To an elongated upper low near 24N89W, and continues southwestward to the northern Yucatan Peninsula. Divergence aloft east of the trough is helping to sustain isolated showers and thunderstorms over the southeastern Gulf and Straits of Florida. Clusters of showers and thunderstorms are along and just inland the northwest part of Cuba. Scattered showers and isolated thunderstorms are over some sections of southwestern part of the basin. Elsewhere, weak high pressure is present over the basin. A weak trough extends from near 30N84W to 27N86W. Isolated weak showers are near the trough. The pressure gradient in place is supporting light to gentle variable winds with 1 to 2 ft seas for the central and eastern Gulf, including the Straits of Florida. Gentle to moderate east to southeast winds and seas of 2 to 4 ft remain across the western Gulf, and also in the Bay of Campeche.

For the forecast, weak high pressure across the eastern U.S. Will continue to extend its ridge into the NE Gulf into Thu allowing for gentle to moderate east to southeast winds and slight seas across the Gulf waters. A weak cold front is forecast to enter the NW Gulf by early Fri, reach from the northeast Gulf to near Cabo Rojo, Mexico by Sat evening, then weaken and stall over the southeast Gulf by late Sun.

Caribbean Sea

PLease see the Tropical Waves section above for information on a tropical wave (Invest-AL94).

The pressure gradient over the area remains fairly weak allowing for generally gentle to moderate trades and 4 to 6 ft seas across the basin. Moderate to occasionally fresh trades are over the far south-central Caribbean and to along the coast of Colombia. Seas over this part of the seas are 5 to 7 ft. Lower seas of 1 to 3 ft are in the the lee of Cuba, and near Costa Rica and Panama.

Scattered showers and thunderstorms confined to south of 12N and west of the coast of NW Colombia to inland Costa Rica and Panama are being enhanced by the eastern extension of the eastern Pacific monsoon trough. Other scattered showers and thunderstorms are over Cuba and over the southern part of Haiti and the southwestern section of the Dominican Republic.

For the forecast, the tropical wave, Invest-AL94, over the eastern Caribbean will move move west-northwestward around 10 to 15 mph, spreading heavy rainfall and gusty winds across Puerto Rico and the Dominican Republic through early tomorrow. The system is then expected to slow down and turn northwestward when it reaches the southwestern Atlantic. Interests in Puerto Rico, the Dominican Republic, the Turks and Caicos Islands, and the Bahamas should monitor the progress of this system. Moderate to fresh east winds and moderate seas will then prevail through the weekend and early next week.

Atlantic Ocean

Please read the Special Features section for information on recently formed Tropical Storm Humberto in the central Atlantic.

The persistent broad upper-level trough across the southeastern United States and the Bahamas continues to enhance shower and thunderstorms in the vicinity of a surface trough across the western Bahamas. No significant winds or seas are noted with the trough at this time. Elsewhere outside of Special Features, the subtropical ridge controls the general weather pattern allowing for gentle to moderate trades and seas of 4 to 7 ft.

For the forecast west of 55W, Tropical Storm Humberto has developed, centered near 20.1N 54.9W at 5 PM EDT, and is moving west-northwest at 13 kt. Maximum sustained winds are 35 kt with gusts to 45 kt, and the minimum central pressure is 1008 mb. Humberto will move to 20.9N 56.0W Thu morning, 21.6N 57.0W Thu afternoon, 22.0N 57.5W Fri morning, 22.5N 58.2W Fri afternoon, 22.9N 59.0W Sat morning, and strengthen to a hurricane near 23.6N 60.6W Sat afternoon. Humberto will change little in intensity as it moves to 26.0N 64.3W by Sun afternoon.

Posted 47 minutes ago by NHC Forecaster Aguirre