Tropical Waves

A far eastern Atlantic tropical wave is analyzed near 19W/20W based on satellite imagery and on model diagnostics. It is moving westward at 10-15 kt. Satellite imagery continues to show an ill- defined mid- level cyclonic circulation near 12N19W. Increasing scattered showers and thunderstorms are near the wave from 09N to 12N between 19W and 21W.

An eastern Atlantic tropical wave has its axis along 41W south of 20N moving westward at 15 to 20 kt. No significant convection is noted near this wave.

A central Atlantic tropical wave has its axis along 51W south of 20N moving westward at 15 to 20 kt. No significant convection is noted near this wave.

A central Caribbean tropical wave is along 75W south of 20N. It is moving westward at about 15 kt. A few thunderstorms are active near 15N76W.

Monsoon Trough/ITCZ

The monsoon trough enters the Atlantic near 18N16W and continues southwestward to 14N20W, then to 11N50W. The ITCZ extends from 11N55W to 11N63W. Outside of convection associated with tropical wave, scattered moderate to isolated strong convection is within 60 nm south of the trough between 32W-35W. Scattered moderate convection is from 10N to 12N between 31W and 38W, and from 09N to 12N between 45W and 48W.

Gulf Of America

A mid to upper-level trough stretches from Georgia southward along the Florida peninsula. Associated showers and thunderstorms are active over the north-central Gulf and off far southwest Florida along a surface trough. Another surface trough is analyzed over the far southwest Gulf off Veracruz. A 1018 mb high pressure area is centered over the central Gulf. This pattern is supporting moderate SE winds over the southwest where seas are 3-5 ft. Light to gentle breezes and 1-3 ft are noted elsewhere.

For the forecast, relatively weak high pressure centered over the central Gulf will prevail through early next week. A weak pressure pattern will support mostly gentle to moderate winds and slight to locally moderate seas across much of the basin. A surface trough will generate fresh to locally strong winds north and west of the Yucatan Peninsula in the early evenings. These winds will spread westward away from the peninsula at night as the trough migrates into the SW Gulf.

Caribbean Sea

See Tropical Waves section above for information on convection across the basin.

The pressure gradient between weak high pressure centered S of Bermuda and low pressure over northern Colombia is supporting fresh to strong trades over the south- central basin, with moderate to fresh trades elsewhere, except gentle over the NW basin. Seas are moderate, except 7 to 9 ft in the south-central portion and slight seas over the northwest Caribbean.

For the forecast, the pattern will continue to sustain fresh to strong trade winds and rough seas across the south-central Caribbean through much of the forecast period. Moderate to fresh trades and moderate seas will prevail over the north-central and eastern Caribbean through the weekend and into early next week. A tropical wave will move across the tropical Atlantic and into the far eastern Caribbean early next week enhancing the trade wind flow across those waters. Elsewhere, moderate or lighter winds and slight to moderate seas are expected.

Atlantic Ocean

A weak 1018 mb low is about 480 nm east-southeast of Bermuda near 30N56W, connected by a trough to another low pressure area farther to the northeast. A second trough is southeast of the first, extending from 30N49W to 26N65W. Scattered to numerous showers and thunderstorms are active near these features under diffluent flow aloft between an upper low to the southeast and an upper ridge to the northwest. Farther west, scattered showers and thunderstorms are also active north of 25N east of an upper trough extending across the Florida peninsula. Elsewhere west of 55W, the subtropical ridge dominates, anchored by 1021 mb high pressure between Bermuda and the central Bahamas near 26N68W. Fresh E to SE winds are funneling along the north coast of Hispaniola south of the ridge, supporting 3-5 ft seas. Elsewhere west of 55W, the pattern is supporting gentle to moderate breezes and 2-4 ft. Farther east, 1028 mb high pressure is centered over southwest of the Azores, supporting moderate to fresh NE to E winds and 5-7 ft seas, except fresh to strong NE winds and rough seas off the coast of Mauritania and Senegal.

For the forecast west of 55W, a weak pressure gradient will support mostly light to gentle winds over most of the waters north of 23N going into early next week. Moderate to fresh trades are expected south of about 23N, especially off northern Hispaniola through the period. These trades may pulse to fresh to strong speeds off northern Hispaniola at night through most of the forecast period. Meanwhile, the northern portion of a tropical wave is expected to move through the eastern portion of the area early next week enhancing the trades some.

Posted 0 minutes ago by NHC Forecaster Christensen