Tropical Waves

A tropical wave has been introduced in the far eastern Atlantic, along 24W, south of 13N, based on wave guidance data. The wave is moving westward at 15-20 kt. No significant convection is noted near the trough axis.

A central Atlantic tropical wave is along 44W, south of 17N, moving westward at 15-20 kt. Scattered moderate to isolated strong convection is present from 02N to 11N and between 33W and 51W.

Another central Atlantic tropical wave is along 57W, south of 18N, moving westward at 15 kt. Scattered moderate to isolated strong convection is observed from 02N to 13N and between 51W and 59W.

A western Caribbean Sea tropical wave along 84W, south of 18N, moving westward at 10 kt. No significant convection is noted near the trough axis.

Monsoon Trough Itcz

The monsoon trough enters the Atlantic through the coast of Mauritania near 21N16W and continues southwestward to 09N26W. The ITCZ extends from 09N26W to 07N43W, then continues from 07N45W to 07N56W. Numerous moderate to isolated strong convection is evident from 06N to 15N and east of 21W.

Gulf Of America

Diurnal storms that formed over the western Yucatan peninsula are racing westward at about 25-30 kt as a squall line over the eastern Bay of Campeche. Mariners in these waters can expect gusty winds to 30 kt, suddenly higher seas and some lightning strikes. A few showers are also noted in the eastern Gulf waters.

At the surface, a 1018 mb high pressure system situated south of the mouth of the Mississippi River supports fresh to locally strong easterly winds and seas of 2-4 ft south of 23N and between 89W and 95W. Elsewhere, moderate or lighter winds and slight seas prevail.

For the forecast, relatively weak high pressure extending westward across the basin from the Atlantic will change little through Thu night, then shift northward to near the northern Gulf coast Fri through Sat night. The related pressure gradient will generally maintain gentle to moderate winds east to southeast winds across the Gulf south of about 26N, and light to gentle southeast to south winds north of about 26N, except for fresh to strong northeast to east winds offshore the Yucatan peninsula at night. Slight seas are forecast throughout the basin for the forecast period.

Caribbean Sea

A strong subtropical ridge over the central Atlantic is forcing strong to near gale-force easterly trade winds and rough seas across the central Caribbean Sea. The strongest winds and highest seas are found off NW Colombia. Moderate to fresh easterly breezes and moderate seas are present in the eastern Caribbean, Windward Passage and Gulf of Honduras. Elsewhere, moderate or lighter winds and slight to moderate seas are prevalent.

For the forecast, the pressure gradient between Atlantic high pressure and relatively lower pressures in Colombia will continue to support fresh to strong trades across the central Caribbean through the period, while mostly fresh trades will be elsewhere south of 18N. Moderate to rough seas will accompany these winds. Expect winds to pulse to near-gale force at night offshore of Colombia and in the Gulf of Venezuela through Sat, except on Thu. Moderate or weaker winds will continue over the northwestern part of the basin, except in the Gulf of Honduras where fresh to strong east to southeast winds are forecast at night through the forecast period. A tropical wave currently near 56W will move across the eastern Caribbean Wed and Wed night, across the central Caribbean Thu through Fri night, and across the eastern part of the western Caribbean Sat and Sat night. Scattered showers and thunderstorms are expected to accompany the wave.

Atlantic Ocean

Divergence aloft is producing isolated showers north of 26N and west of 44W. The tropical Atlantic is under the influence of a broad subtropical ridge along 27N. Moderate to fresh easterly trade winds and seas of 4-8 ft are found south of 24N and west of 30W. However, strong winds are noted off northern Hispaniola. Moderate to locally strong N-NE winds and seas of 4-8 ft are evident from 18N to 29N and east of 30W. Elsewhere, moderate or weaker winds and moderate seas prevail.

For the forecast west of 55W, high pressure over the area will change little through the forecast period. The associated gradient will continue to support moderate to fresh trades south of 23N, and moderate or weaker winds elsewhere. Strong winds along with moderate to rough seas are expected at night north of Hispaniola, including approaches to the Windward Passage through Sat night.

Posted about 3 hours ago by NHC Forecaster Delgado