Tropical Waves

A tropical wave is analyzed near 39W, S of 18N. This is an adjustment from previous analyses and combined two analyzed wave to better reflect current and forecast conditions. The combined wave is moving W at 10 kt, and is inducing scattered moderate convection from 05N to 10N between 33W and 43W.

An Atlantic tropical wave is near 56W, S of 17N, moving W at around 20N. Scattered moderate convection associated with this wave is noted S of 12N between 51W and 59W.

A Caribbean tropical wave axis is near 81W, south of 18N, moving W at around 10 kt. Scattered moderate to isolated strong convection is noted S of 15N and W of 80W.

Monsoon Trough/ITCZ

The monsoon trough enters the Atlantic near 18N17W and continues to 11N19. The ITCZ stretches from 09N22W to 07N33W and from 07N41W to 07N53W. Aside from convection associated with the tropical waves, described above, scattered moderate convection is noted within 120 nm of the segment of the ITCZ that extends from 22W to 33W.

Gulf Of America

Subtropical ridging continues to be the dominant feature over the basin, with the axis extending into the central Gulf from the east. A surface trough that extends from near Tampa Bay to Mobile Bay is generating scattered moderate convection across the northern Gulf. Winds are moderate or weaker, mainly anticyclonic, through the basin, with generally slight seas, with the except of some 3 to 5 ft seas in the Bay of Campeche.

For the forecast, surface ridging will prevail across the basin through the forecast period, thus supporting gentle to moderate winds over the western half of the Gulf, except for fresh to strong ENE winds offshore the Yucatan peninsula at night. Moderate or weaker winds are forecast for the eastern half of the Gulf while slight seas are forecast basin-wide.

Caribbean Sea

The pressure gradient between the subtropical ridge and lower pressure over northern South America continue to support fresh to strong trades over the central basin, with moderate to fresh E winds elsewhere. Seas of 8 to 11 ft are present in the central basin, with slight seas in the NW basin, and 5 to 7 ft seas elsewhere. Convection in the far SW basin is associated with a tropical wave and is described in the above section. Scattered moderate convection is noted between the Cayman Islands and western Cuba, being induced by upper-level divergence.

For the forecast, the pressure gradient between the Atlantic ridge north of the basin and the Colombian Low will continue to support fresh to strong trade winds and moderate to rough seas over the central Caribbean through the week. The aerial extent of these winds will continue to increase today as the Atlantic ridge continues to build westward. By Wed, the fresh to strong winds are expected to extend across most of the east, central and SW Caribbean. Expect winds to reach near-gale force at night offshore of Colombia and in the Gulf of Venezuela through Fri. Moderate or weaker winds will prevail over the NW part of the basin, except in the Gulf of Honduras where fresh to strong E to SE winds are forecast at night through the forecast period.

Atlantic Ocean

The Atlantic subtropical ridge dominates the Atlantic north of 20N, and is anchored by 1026 mb high pressure centered near 29N39W. The pattern is supporting gentle to moderate breezes and 3-5 ft seas for waters N of 22N, with mainly fresh trades and 5 to 7 ft seas to the south. Upper level divergence to the east of a trough aloft is leading to scattered moderate convection N of 23N and W of 65W, including in the vicinity of the Bahamas.

For the forecast west of 55W, the Atlantic subtropical ridge will stay in place through the forecast period, developing a center of high pressure E of the Bahamas by Fri. This pattern will continue to support moderate to fresh E to SE trade winds S of 23N, and moderate or weaker winds elsewhere. Strong winds, with moderate to rough seas are expected at night north of Hispaniola, including approaches to the Windward Passage, through Fri night

Posted 0 minutes ago by NHC Forecaster Konarik