Tropical Waves

An eastern Atlantic tropical wave has its axis along 26N, south of 17N, moving westward at 5 to 10 kt. Scattered moderate convection is about the wave from 07N to 13N between 23W and 30W.

A central Atlantic tropical wave has its axis near 44W, south of 18N, moving westward at 15 kt. No significant convection is associated with this wave at this time.

An eastern Caribbean tropical wave has its axis near 65W, south of 19N, moving westward at around 15 kt. Scattered moderate convection is observed over Venezuela from 03N to 10.5N between 60W and 67W.

A western Caribbean tropical wave has its axis along 86W, south of 20N, moving westward at about 15 kt. Scattered moderate convection is noted, mostly over land, from 09N to 16N between 80W and 87W.

Monsoon Trough/ITCZ

Th monsoon trough enters the Atlantic through the coast of Senegal near 14N17W and continues southwestward to 10N33W to 11N43W. The ITCZ extends from 08N52W to 12N64W. Scattered moderate isolated strong convection is evident from 05N to 14N and east of 22W. Scattered moderate convection is noted from 11N to 14N between 30W and 38W. Widely scattered moderate convection is noted from 07N to 10N between 51W and 62W.

Gulf Of America

Weak high pressure centered across the Gulf waters south of the mouth of the Mississippi River supports moderate W-NW winds across the NE Gulf, and mainly moderate NE to E winds across the southern Gulf. Slight seas to 3 ft dominate the basin. An upper level low across the NW Gulf of combining with a low level wind surge moving across the western Bay of Campeche to produce squattered moderate convection there. Meanwhile, scattered to locally numerous moderate to strong afternoon convection has fired up across the western portions of the Yucatan Peninsula and the adjacent Gulf waters, and is gradually shifting westward.

For the forecast, high pressure will prevail across the Gulf waters through the remainder of the week into the weekend. A weak pressure pattern will support mostly gentle to moderate winds across much of the basin. A diurnally induced surface trough will generate fresh to locally strong winds north and west of the Yucatan peninsula early each evening. These winds will spread westward away from the Yucatan at night as the trough migrates into the SW Gulf. Slight to moderate seas are expected through the forecast period.

Caribbean Sea

The subtropical ridge recently north of the Caribbean has shifted eastward as a frontal system has moved southward of 30N and become stationary along about 27N, from east of the Bahamas into the central Atlantic. The remnants of the ridge extend from the central Atlantic to N of Puerto Rico along 22N. This weakened pressure pattern is supporting moderate to fresh easterly trade winds and seas of 5-8 ft from 68W into Central America, with light to gentle winds and slight to moderate seas are found elsewhere. Thunderstorms area active across the coastal waters and inland from Costa Rica to NE Honduras, behind a tropical wave.

For the forecast, central Atlantic high pressure will begin to build westward and into the Bahamas tonight through Fri. The pressure gradient between this ridge N of the basin and the Colombian low will support fresh to strong trade winds and rough seas offshore of Colombia tonight, then expand across much of the south- central Caribbean through the remainder of the forecast period. Moderate to fresh trades and moderate seas will prevail in the north- central and eastern Caribbean into the weekend. Elsewhere, moderate or lighter winds and slight to moderate seas are expected.

Atlantic Ocean

A cold front enters the local waters near 31N50W and extends southwestward to a 1015 mb low center near 28N64.5W then continues to near 27N72W. Scattered moderate isolated strong convection is noted along within 150 nm S and SE of the front and low. Moderate to locally fresh SW winds and seas of 4-7 ft are noted south of the front to 24N between 44W and 70W. The remainder of the tropical Atlantic is dominated by a broad ridge centered on a 1027 mb high near 40W32W, that extends southwestward to just north of the NE Caribbean. Trade winds across the Atlantic S of 22N and W of 30W are moderate or lighter winds and moderate seas. However, fresh northerly winds and seas of 5-8 ft are found in the far eastern Atlantic off NW Mauritania and southern Western Sahara. Saharan Air continues to dominate the Atlantic basin N of 15N and east of the Caribbean, as well as the southern Bahamas, NW Caribbean and into the SE Gulf of America.

For the forecast west of 55W, the aforementioned front will weaken into a trough tonight and gradually dissipate as it lifts northward through Thu. Central Atlantic high pressure will then build westward into the area. A weak pressure gradient will support mainly light to gentle winds, locally moderate, across much of the area N of 22N through the week and into the weekend. Moderate to locally fresh easterly trade winds can be expected S of 22N.

Posted 47 minutes ago by NHC Forecaster Stripling