Tropical Waves

A far eastern Atlantic tropical wave has its axis along 21W from 03N to 16N. It is moving westward near 10 kt. Numerous moderate to strong convection is within 240 nm east of the wave from 07N to 13N. Scattered moderate to isolated strong convection is within 120 nm west of the wave from 07N to 11N.

An eastern Atlantic tropical wave has its axis along 35W from 02N to 16N moving westward at 15 to 20 kt. Isolated showers and thunderstorms are seen within 180 nm either side of the wave from 02N to 06N.

A central Atlantic tropical wave has its axis along 56W south of 18N to inland Suriname. Scattered showers and thunderstorms are within 120 nm east of the wave from 08N to 12N and close to the wave axis near 05N56W.

A central Caribbean tropical wave is along 77W south of 19N. It is moving westward at about 15 to 20 kt. An upper-level low west of the wave near 18N84W is providing upper divergence. This is helping to fire-up scattered moderate to isolated strong convection west of the wave to near 81W from 15N to 18N. Isolated showers and thunderstorms are within 60 nm east of the wave over Colombia.

Monsoon Trough/ITCZ

The monsoon trough axis enters the Atlantic off the coast of Mauritania, and continues southwestward to near 08N27W, then westward to 07N41W, where it transitions to the ITCZ to 08N46W and to 07N55W. Scattered moderate convection is from 04N to 08N between 23W and 33W.

Gulf Of America

Relatively weak high pressure ridging stretches westward from the western Atlantic to across Florida and to the central Gulf. A 1018 mb high center is along the ridge near 27N84W. The pressure gradient between the ridge, and a trough that extends from 25N88W to 22N92W and to inland Mexico at 18N92W has induced mostly fresh southeast winds offshore the northern Yucatan Peninsula, reaching north to near 26N and between 88W and 92W. Seas are 5 to 7 ft with these winds. Elsewhere, moderate to fresh east to southeast winds are over most of the basin west of 88W, while gentle to moderate or weaker winds remain east of 88W. Both buoy and satellite altimeter data indicate seas of 4 to 6 ft across the basin, except for slightly higher seas of 5 to 7 ft over the north-central and NW sections.

Scattered showers and thunderstorms are offshore the Texas coast from just northeast of Padre Island to near Matagorda Island. This activity extends east to near 96W. Meanwhile, isolated showers and thunderstorms, albeit less in coverage than a few hours ago, are over the southeast Gulf and near the lower Florida Keys.

For the forecast, the pressure gradient between the high pressure ridge and relatively lower pressures over Texas and northeastern Mexico will generally support mostly fresh southerly winds over the western and central Gulf through the weekend. These winds are expected to diminish to gentle to moderate speeds early next week. Slight to moderate seas will accompany these winds. Weak high pressure over the eastern Gulf will support light to anticyclonic winds and slight seas there through late Mon. A new high center will become established over the central Gulf by midweek, with similar conditions expected over much of the basin at that time.

Caribbean Sea

The pressure gradient between high pressure over the central Atlantic and relatively lower pressures in northern South America is sustaining fresh to strong trade winds over a good portion of the central Caribbean. Seas with these winds are in the range of 6 to 9 ft as detected by earlier satellite altimeter data passes across that portion of the sea. Fresh to strong trade winds are over the Gulf of Honduras surrounding waters. Seas are 6 to 8 ft over this area. Moderate to fresh trade winds along with seas of 5 to 7 ft in east swell are over the eastern section of the basin. Gentle to moderate east to southeast trade winds are over the north-central and northwestern portions of the sea along with seas of 4 to 6 ft, except fluctuating at times to 5 to 7 ft over the waters between Jamaica and 15N and from 18N to 15N between 70W and 76W. Mostly gentle trade winds are elsewhere along with seas of about 3 to 4 ft.

An area of recently developed scattered moderate to isolated strong convection is southwest of Jamaica from 15N to 17N between 77W and 81W. This activity is developing under upper divergence provided by an upper-level low near 18N84W as seen in water vapor imagery. Similar convection is confined to the southwestern section of the Caribbean south of 11N to along the coasts of Costa Rica and Panama, primarily due to the close proximity of the eastern segment of the East Pacific monsoon trough.

For the forecast, high pressure will prevail north of the area into next week. The pressure gradient between the high pressure and lower pressures in northern South America will support fresh to strong trade winds and moderate to rough seas in the central Caribbean through the forecast period, with highest winds and seas expected off the coast of Colombia. Pulsing fresh to strong winds and moderate to rough seas are expected in the Gulf of Honduras nightly well into the upcoming week. Moderate to fresh winds are expected over much of the remainder of the Caribbean through the middle portion of next week. A tropical wave currently east of the Lesser Antilles near 56W will move through the eastern Caribbean Sun through late Mon, and across the rest of the basin through late Wed. Scattered showers and thunderstorms are expected near the wave.

Atlantic Ocean

Three tropical waves are moving westward between West Africa and the Lesser Antilles. Please see the Tropical Waves section for details on these features.

High pressure dominates the Atlantic forecast region, with a 1022 mb high center analyzed near 27N57W. The pressure gradient between the high and relatively lower pressure to the south, including near the tropical waves, is sustaining mostly moderate to fresh trade winds over the majority of the waters south of about 22N as well as over the waters between the southeastern Bahamas and Hispaniola. A satellite scatterometer data pass from yesterday evening revealed fresh to strong north winds over the far eastern Atlantic between the coast of Africa and 20W from 18N to 24N as a tight gradient exists there between low pressures over Africa and the southeast periphery of Atlantic high pressure. Seas are in the range of 5 to 6 ft over these waters as suggested by a satellite altimeter pass from last night. Latest scatterometer satellite data passes indicate that light to moderate winds are elsewhere across the domain.

Isolated showers and thunderstorms are observed over and near the central Bahamas and between southeast Florida and Andros Island. Similar activity is seen north of 29N between 74W and 80W as a mid to upper-level trough slides eastward east of northern Florida. Isolated weak showers are north of 29N between 43W and 57W.

For the forecast west of 55W, the relatively weak high pressure will continue over the basin at least into the early part of next week. A weak frontal boundary will move offshore northeast Florida today, then stall and lift north as a warm front tonight into Sun. Fresh southwest winds north of 29N and between 65W and 74W will diminish this afternoon. Moderate to fresh trade winds will pulse to strong south of 22N into early next week, then be at mostly fresh speeds through the rest of the forecast period.

Posted 2 hours ago by NHC Forecaster Aguirre