Tropical Waves

A far eastern Atlantic tropical wave has its axis along 20W from is in the far eastern Atlantic from 02N to 16N, moving westward at 10-15 kt. Scattered moderate to isolated strong convection is within 240 nm either side of the wave from 04N to 06N.

Another eastern Atlantic tropical wave has its axis along 35W from 02N to 16N, moving westward at about 15 kt. Isolated, mostly light showers are from 07N to 10N between 32W and 36W.

A central Atlantic tropical wave has its axis near 53W south of 19N. It is moving westward near 15 kt. No significant convection is currently occurring with this wave.

A central Caribbean tropical wave has its axis along 79W south of 18N, moving westward at 10 kt. Isolated showers are near the axis within 30 nm of 15N79W.

Monsoon Trough/ITCZ

The monsoon trough axis enters the Atlantic through the coast of Guinea-Bissau near 12N16W and continues southwestward to 07N26W where it transitions to the ITCZ extends to 05N35W. It resumes at 05N36W to the Brazil near 00.5N50W. Scattered moderate to isolated strong convection from 02N to 06N between 05W-16W. Scattered moderate convection is within 120 nm south of the ITCZ between 26W-30W, and within 60 nm north of the ITCZ between 26W-28W.

Gulf Of America

A persistent broad area of low pressure present is over the southwestern Gulf just offshore Mexico. Deep convection seen during the morning over the southwestern Gulf has diminished. Latest satellite imagery shows numerous moderate-type convection from 19N to 23N between 92W and 95W. Scattered showers and isolated thunderstorms are elsewhere from 19N to 25N west of 91W. At the surface, a tight pressure gradient between the low pressure area and the Atlantic ridge that extending westward into the north-central Gulf is generally maintaining fresh to strong southeast winds along with moderate to locally rough seas to around 9 ft south of 26N and west of 88W. Elsewhere, moderate or weaker anticyclonic winds and slight to moderate seas prevail.

For the forecast, the aforementioned broad area of low pressure will move inland northeastern Mexico by early Sun. The system could re-emerge over the NW Gulf on Tue or Wed while interacting with a frontal boundary, however, conditions there are also expected to be only marginally conducive for development. The pressure gradient between the low pressure area and a ridge over the NE Gulf will support fresh to strong SE winds and moderate to rough seas, accompanied by scattered showers and thunderstorms, through Sun night. Atlantic high pressure will build westward into the Gulf Tue and Wed, with the associated pressure gradient leading to moderate to fresh southerly winds basin-wide.

Caribbean Sea

The subtropical ridge over the central Atlantic extends westward near 27N to across Florida. The related pressure gradient is generally allowing for fresh to near gale-force trade winds along with moderate in the central and southeastern portions of the Caribbean and Gulf of Honduras as seen in the latest scatterometer data passes. Moderate to fresh trade winds along with moderate seas are elsewhere, except for lighter trades winds of gentle speeds over the waters between Cuba and 20N west of about 75W. Seas are in the 2 to 4 range with these winds. Moderate or lighter winds along with slight to moderate seas are elsewhere across the basin.

Isolated showers and thunderstorms are north of 18N between southwestern Haiti and 84W, including the approach to the Windward Passage, as divergence aloft sustains this activity. Strong convection across interior portions of the Gulf of Honduras and over southern Belize is along the southeast periphery of the area of broad low pressure that is in the southwestern Gulf of America.

For the forecast, the Atlantic ridge will generally remain in place through Sun, with its related pressure gradient allowing for a large area of fresh to strong trade winds and moderate to rough seas across the central Caribbean. Expect highest winds and seas off the coast of Colombia. Fresh to strong southeast winds and rough seas will also persist over the Gulf of Honduras and northwestern Caribbean west of 85W through tonight. The ridge north of the area will reorganize Sun night through Mon then shift slowly northeastward through midweek, leading to a slight decrease in wind and seas across the basin.

Atlantic Ocean

A stationary front extends from 31N36W to 29N41W, then dissipating to 29N43W and trough to 29N47W and to near 31N52W. Isolated rather weak showers are seen from 29N to 30N between 46W and 49W. The remainder of the tropical Atlantic is dominated by a broad subtropical ridge that extends across central Florida, and that is anchored by a 1026 mb high near 31N30W and a 1022 mb high near 26N58W, supporting moderate to fresh trade winds south of 21N west of 35W along with mostly moderate seas. Moderate to fresh northerly winds and moderate seas exist north of about 15N and east of 22W while moderate northeast winds are from 12N to 25N between 22W and 35W. Seas are in the moderate range are in these areas. Elsewhere, moderate or weaker winds and slight to moderate seas prevail.

For the forecast west of 55W, the Atlantic ridge will generally remain in place through Sun. The ridge will then reorganize along about 60W Sun night and Mon, then shift slowly NE Tue through Wed. This pattern will support moderate E to SE trade winds S of 22N and a gentle anticyclonic flow elsewhere through Sun. Fresh southwest winds will develop across the northwest waters north of about 29N and west of 74W Sun evening through Tue as a weak frontal system moves through the SE U.S. Expect fresh to strong winds each afternoon through late evening across Atlantic waters near Puerto Rico and Hispaniola.

Posted 1 hour, 29 minutes ago by NHC Forecaster Aguirre