Tropical Waves

A tropical wave is added to the 1800 UTC analysis/surface map along 18W S of 15N. The wave shows up well on satellite imagery and model diagnostic guidances. The cloud pattern is exhibiting some cyclonic circulation. Scattered moderate isolated strong convection is noted from 06N to 10N between 18W and 23W. Similar convective activity is also noted over W Africa.

A tropical wave is along 33W S of 16N moving west at 15 to 20 kt. Scattered moderate convection is noted where the wave meets the monsoon trough.

Another tropical wave is along 53W S of 18N moving west at 15 to 20 kt. The associated convective activity shows an inverted "V" pattern, particularly from 08N to 12N between 48W and 57W.

A tropical wave is moving across the eastern caribbean at 10 to 15 kt. Its axis is along 68W/69W S of 17N. The wave appears to enhance convection over western Venezuela.

Monsoon Trough Itcz

The monsoon trough axis enters the Atlantic off the coast of Mauritania, and continues southwestward to near 08N27W, then westward to 07N40W. The ITCZ extends from 07N40W to 07N50W. Most of the convective activity across the area is related to the tropical waves described above.

Gulf Of America

The Atlantic ridge extends westward across Florida into the Gulf region. The pressure gradient between the ridge and lower pressures across Mexico and southern Texas supports moderate to fresh SE to S winds across the west and central Gulf, and gentle to moderate winds across the eastern Gulf. Seas are 5 to 7 ft W of 90W, and 3 to 5 ft E of 90W, except 1 to 3 ft across the offshore waters of west Florida south of Tampa Bay, and between western Cuba and the Florida Keys where seas are in the 1 to 3 ft range. Numerous showers and thunderstorms located near the southeastern United States coast and adjacent offshore waters are associated with a trough of low pressure (the remnants of Arthur). Similar convective activity is also noted over parts of the State of Florida.

For the forecast, as previously mentioned, the pressure gradient between the ridge and relatively lower pressures over Texas and northeastern Mexico will generally support mostly fresh southerly winds over the western and central Gulf. These winds over the western and central Gulf will diminish to gentle to moderate speeds early next week. Winds over the eastern Gulf will become light to gentle tonight.

Caribbean Sea

The pressure gradient between the Atlantic high pressure and lower pressures in northern South America is generally sustaining fresh to strong trade winds over the central Caribbean where an altimeter pass indicates seas of 8 to 11 ft. Similar winds speeds are also noted over the western Caribbean W of 85W, including the Gulf of Honduras, with seas of 5 to 8 ft. Moderate to fresh trades and seas of 4 to 6 ft are over the eastern Caribbean. Elsewhere, gentle to moderate winds and seas of 3 to 5 ft prevail. Scattered showers and thunderstorms are over the SW Caribbean. Some convective activity is flared-up over parts of the Greater Antilles likely due to daytime heating, local sea breezes and mountain slope lifting.

For the forecast, high pressure will prevail north of the area into next week. The pressure gradient between the area of high pressure and the Colombian low 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 through Mon, pulsing briefly to near gale-force tonight. Moderate to fresh winds are expected over much of the remainder of the Caribbean through Mon night.

Atlantic Ocean

Three tropical waves are moving westward between W Africa and the Lesser Antilles. Please, see the Tropical Waves section for more details.

High pressure dominates the entire Atlantic forecast region, with a 1024 mb center near 28N57W. Under the influence of this system, a light to gentle anticyclonic flow is noted N of 22N and E of 70W while moderate to fresh southwest winds are over the waters east of northern Florida to near 70W. Seas are in general moderate with these winds. Moderate to locally fresh trades prevail over the tropical Atlantic along with seas of 5 to 7 ft.

For the forecast west of 55W, high pressure across the basin will shift slightly eastward tonight as a cold front moves across the southeastern U. S. The front will move offshore northeast Florida during the weekend, then stall and weaken. Fresh to strong southwest winds are expected north of 30N and W of 72W through tonight. Moderate to fresh winds will pulse to strong south of 22N into early next week.

Posted about 1 hour ago by NHC Forecaster GR