Tropical Waves

A tropical wave is along 20W from 13N southward, moving westward at 5-10 kt. Scattered moderate convection, enhanced by the Monsoon Trough and nearby ITCZ, is from 01N to 06N between 10W and 23W.

A tropical wave is analyzed along 48W, south of 12N, moving westward at 10-15 kt. Scattered moderate convection is from the equator to 05N between 47W and 51W, including coastal regions of far NE Brazil.

A tropical wave in the western Caribbean is near 81W, south of 15N and into the Eastern Pacific region to near 05N. This wave is nearly stationary, with surface and upper air data from San Andres Island indicating the wave remains east of the island. Scattered showers and tstorms are along the coasts of Panama and Costa Rica.

Monsoon Trough Itcz

The monsoon trough enters the Atlantic near 14N17W and continues southwestward to 04N23W. The ITCZ extends from 04N23W to 01N43W, east of a tropical wave. Outside of the convection related to the tropical waves, scattered moderate convection is within 120 nm north and south of the ITCZ.

GULF OF AMERICA,

Scattered moderate convection is along the coast of Louisiana, north of 28N between 88W and 94W. Scattered moderate convection is also moving off the south Texas coast. These unsettled areas of weather will persist for the next several hours over water. Elsewhere, the subtropical Atlantic ridge extends across Florida and much of the central and eastern Gulf waters. Satellite scatterometer data indicates gentle to moderate SE winds across the basin. Seas are analyzed to range from 2-4 ft. The diurnal trough in the Bay of Campeche dissipated earlier this morning.

For the forecast, high pressure extending from the western Atlantic to the northern Gulf will change little through late Mon, then weaken into midweek. The related pressure gradient will maintain a gentle to moderate east to southeast wind flow through early Sun, except for light to gentle southeast winds W of about 94W Sat night through Tue as a weak trough develops off the Texas coast. Winds then generally become southeast at gentle to moderate speeds across the basin through midweek, with slight to moderate seas, with the exception of fresh to strong winds pulsing off NW Yucatan from the late afternoons and into the night time hours due to local effects associated with a thermal trough. Scattered showers and thunderstorms are expected near the above mentioned trough.

CARIBBEAN SEA,

The pressure gradient between high pressure N of the region and the Colombian Low supports fresh to locally strong trades in the south-central Caribbean, where seas are 7 to 9 ft. Elsewhere, satellite scatterometer data received this morning indicates moderate to fresh trades across the basin. Satellite altimeter data supports an analysis of 4-7 ft seas across the Caribbean. Pockets of low-level moisture, embedded in the trade wind flow, are affecting the remainder of the region by generating isolated passing showers.

For the forecast, the pressure gradient between high pressure north of the area and relatively lower pressures in northern South America will support fresh to strong trades over the south- central Caribbean into early next week creating rough seas over these waters. Fresh to strong trades will also pulse each evening over the Gulf of Honduras. Mostly moderate trades elsewhere across the basin will begin to increase in coverage starting early next week as stronger Atlantic high pressure begins to shift southeastward tightening the pressure gradient.

ATLANTIC OCEAN,

High pressure dominates the Atlantic waters, providing for gentle to moderate trades and 4-7 ft seas across the basin. Pockets of low-level moisture embedded in the trade wind flow may generate a few passing showers, especially in the western Atlantic.

For the forecast west of 55W, high pressure will continue to dominate most of the forecast region this weekend into early next week. Fresh to strong trades will pulse north of Hispaniola during the afternoons and evenings going into early next week. The western part of a backdoor cold front will push south across the eastern portion of the area from Sun afternoon into Mon before stalling near 26N, then begin to weaken, dissipating on Tue. Fresh to strong northeast winds along with moderate to rough seas will follow the front, subsiding late Tue. Elsewhere, trades are forecast to increase over most of the western half of the area starting Mon, including the waters between Cuba and the Bahamas as well as the entrance to the Windward Passage as stronger Atlantic high pressure begins to shift southeastward tightening the pressure gradient.

Posted about 5 hours ago by NHC Forecaster Mahoney