Tropical Waves

A tropical wave is near 62W from 22N southward across the Lesser Antilles to northeastern Venezuela. It is moving west near 15 kt. Scattered showers and isolated thunderstorms are seen near and northeast of the Virgin Islands to near 23N.

A central Caribbean tropical wave is near 73W from 20N southward, and moving west near 15 kt. Scattered moderate convection is inland over western Venezuela.

A western Caribbean tropical wave is near 83W from near the Island of Youth southward across Honduras, Nicaragua and It is moving west at 15 to 20 kt. Scattered showers and tstorms are inland across Nicaragua and NE Honduras.

Monsoon Trough Itcz

A monsoon trough enters the Atlantic along the Mauritania coast near Nouakchott, then curves southwestward across 13N20W to 08N30W. An ITCZ continues westward from 08N30W to 07N50W. Scattered moderate convection is occurring near and south of the monsoon trough from 07N to 09N between 30W and the Guinea- Bissau/Sierra Leone. Widely scattered showers and isolated thunderstorms are found up to 150 nm along either side of the ITCZ.

The eastern end of the East Pacific monsoon trough is triggering scattered showers and isolated thunderstorms at the Caribbean waters near western Panama.

Gulf Of America

A diurnal surface trough is causing scattered heavy showers and isolated strong thunderstorms at the southeastern Bay Campeche. A surface trough over Florida is triggering similar convection near Naples, Florida. Otherwise, a modest 1020 mb high over the east- central and southeastern Gulf is promoting light to gentle winds and seas of 1 to 3 ft for most of the Gulf, except gentle to moderate NE to ENE winds and seas at 2 to 4 ft for waters near the Yucatan and north coast of Cuba.

For the forecast, modest high pressure will dominate the basin through the forecast period, supporting mostly gentle to moderate winds and slight to moderate seas. Scattered showers and thunderstorms are expected to increase across the northern Gulf this weekend into Mon as a weak low pressure develops in the vicinity of SE Louisiana, along a stalling frontal boundary.

Caribbean Sea

Convergent trades are producing widely scattered showers near the lee of Cuba and Windward Passage. Refer to the Tropical Waves and Monsoon Trough/ITCZ sections for additional weather in the Caribbean Sea. A 1027 mb high near 29N53W continue to channel trade winds across much of the basin. Fresh to strong ENE to E winds and seas of 9 to 11 ft are present at the south-central basin. Moderate to fresh NE to E winds and 6 to 9 ft seas are noted at the north-central and part of the southwestern basin. Gentle to moderate NE to E winds with seas of 3 to 5 ft prevail for the rest of the Caribbean Sea.

For the forecast, the pressure gradient between the 1027 mb high and the Colombia low will continue to allow for fresh to strong winds and rough seas over the south-central basin through Wed night. The strongest winds will occur off the coast of Colombia, occasionally pulsing to near gale-force at night. Moderate to fresh trades will prevail over the eastern basin while moderate or weaker winds are forecast for the northwestern basin. Otherwise, a tropical wave accompanied by scattered showers and thunderstorms, currently moving across the Lesser Antilles, will move across the eastern basin on Sat, the central basin Sat night into Sun and across the southwestern basin Sun night into Mon.

Atlantic Ocean

The tail end of a surface trough originated from the north-central Atlantic is creating widely scattered moderate convection north of 28N between 41W and 48W. Otherwise, a large dome of 1027 mb high near 29N53W is supporting light to gentle winds and 2 to 4 ft seas north of 26N between 35W and the Florida/southern Georgia coast, except gentle to moderate NE winds with seas at 3 to 5 ft north of 26N between 35W and 40W. To the south, moderate to fresh NE to ESE winds and seas at 4 to 7 ft are present from 12N to 26N between 35W and the Bahamas/Lesser Antilles. Mainly gentle E to SE winds and seas of 3 to 6 ft prevail elsewhere in the Atlantic Basin west of 35W.

For the forecast west of 55W, high pressure will dominate the weather pattern through midweek next week, supporting a gentle to moderate anticyclonic flow and slight to moderate seas across the western Atlantic. The pressure gradient between a tropical wave currently moving across the Lesser Antilles and the 1027 mb high will support an area of fresh to locally strong E to SE winds with moderate to rough seas that will move north of the Leeward Islands and Puerto Rico through Sat, and north of Hispaniola Sat night into Sun. Winds and seas will diminish Sun as the high pressure weakens.

Chan Posted 26 minutes ago by NHC Forecaster