Tropical Waves

A tropical wave has its axis along 28W south of 19N moving westward at 10 to 15 kt. Scattered moderate to isolated strong convection is near the southern end of the wave axis from 05N to 10N between 26W and 32W.

Another tropical wave has its axis along 47W/48W south of 19N moving westward at 15 to 20 kt. A few showers are near the northern end of the wave axis.

A tropical wave is approaching the Lesser Antilles. Its axis is along 60W south of 20N. It is moving westward at 15 to 20 kt. Convection is limited near the wave axis at this time. However, moisture associated with this wave is forecast to reach mainly the Windward Islands tonight into Sun likely increasing the likelihood of showers.

A tropical wave is over the western Caribbean along 82W south of 20N. It is moving westward at 10 to 15 kt. The wave appears to enhance convection over parts of Panama and Costa Rica as well as over the Atlantic plains of Nicaragua.

Monsoon Trough/ITCZ

The monsoon trough axis enters the Atlantic through the coast of Mauritania near 18N16W and continues southwestward to 08N28W, and northwestward from there to 11N50W. The ITCZ extends from 11N50W to 11N59W. No significant convection is noted outside of what is described in the Tropical Waves section above.

Gulf Of America

Scattered showers and thunderstorms are active across most of the northern Gulf ahead of surface trough that extends from SE Georgia to the coast of Louisiana. Additional showers and thunderstorms are active over the Yucatan Peninsula. Elsewhere, a ridge continues to dominate the Gulf waters, anchored by 1018 mb high pressure located near 24N94W. This pattern is supporting light to gentle winds and slight seas, except for gentle to moderate winds and 3 to 5 ft seas over the Bay of Campeche east of the trough in that area.

For the forecast, weak high pressure will remain centered over the basin into late next week, leading to gentle to moderate winds and generally slight seas. A surface trough will generate fresh winds north and west of the Yucatan Peninsula in the early evenings, which will pressure further offshore through the Bay of Campeche during the overnight hours.

Caribbean Sea

The pressure gradient associated to high pressure over the western Atlantic and relatively lower pressure in northern South America is sustaining fresh to strong trades primarily over the south- central Caribbean. Seas in the range of 8 to 9 ft are with these trades as noted in recent altimeter data. Moderate to fresh trades and moderate seas are elsewhere, except in the NW Caribbean where light to gentle winds and slight to moderate seas are noted. Convection is flared-up over much of Central America and Cuba, and over parts of Dominican Republic.

For the forecast, the pressure gradient between western Atlantic high pressure and Colombia low pressure will support fresh to strong trades and resultant rough seas over the south-central Caribbean through next week. Elsewhere, mainly moderate to fresh trades and moderate seas will prevail, aside from light to gentle winds and slight seas in the NW part of the basin. A pair of tropical waves crossing the Caribbean Sea next week lead to periods of enhanced winds after their passages.

Atlantic Ocean

A 1021 mb high pressure centered between the Bahamas and Bermuda near 29N68W dominates the western Atlantic west of 60W. A surface trough extends from 31N75W to 28N80W. Showers and thunderstorms are associated with this trough. Satellite derived wind data indicate mainly gentle to moderate winds on either side of the trough axis. Moderate to locally fresh E to SE winds and seas of 3 to 5 ft are noted off Hispaniola and eastern Cuba, including approaches to the Windward Passage. Light to gentle winds and slight to moderate seas prevail elsewhere W of 60W. Farther east, a weak 1016 mb low pressure is located near 29N59W. A trough extends from the low center to near 27N60W based on scatterometer data. Scattered showers, with embedded thunderstorms, are ahead of these features. The remainder of the forecast area in under the influence of broad 1028 mb high pressure centered north of the region near 35N41W. This pattern is supporting moderate to fresh NE to E winds and 5 to 7 ft seas across the basin, with the exception of fresh to strong N to NE winds and rough seas from 19N to 23N E of 22W to the coasts of Mauritania and Western Sahara. A cold front is approaching the Madeira Islands. Some shower activity is along the frontal boundary.

For the forecast west of 55W, weak low pressure that has developed well SE of Bermuda will drift west through the weekend then lift northward and out of the region Mon. Otherwise, high pressure will maintain light to gentle winds N of 23N through the period. To the south, moderate to fresh trades will prevail, with locally strong winds pulsing at times offshore Hispaniola and into the Windward Passage. The northern portion of a tropical wave will move across the waters S of about 23N and E of the Bahamas early next week freshening the trades. By Wed, the northern portion of another tropical wave may move across the SE portion of the area, increasing the trades over those waters.

Posted 1 hour, 29 minutes ago by NHC Forecaster Gr