Tropical Waves

The axis of a tropical wave is near 42W, S of 15N, moving west at 10 to 15 kt. No significant convection is observed near this wave.

The axis of a tropical wave is near 55W, S of 15N, moving westward at around 15 kt. Scattered moderate convection is observed S of 10N between 53W and 58W.

The axis of a tropical wave is near 62W, S of 18N, moving westward at 10 to 15 kt. No significant convection is associated with this wave at this time.

Monsoon Trough/ITCZ

The monsoon trough extends off the coast of Africa near 12N16W and extends SW to 05N30W. The ITCZ extends from 05N30W to 02N51W. Numerous moderate to strong convection is along and within 150 nm of the monsoon trough and ITCZ from 30W eastward. Scattered showers and isolated thunderstorms are along and within 100 nm of the remainder of the ITCZ.

Gulf Of America

Moderate to fresh E to SE winds persist over the Gulf south of 25N, driven by the pressure gradient between a weak subtropical ridge and T.S. Cristina in the Eastern Pacific near the coast of El Salvador. Seas are 5-7 ft in the south-central Gulf, and 2-5 feet elsewhere. A surface trough is analyzed from the Bay of Campeche along the Mexican coast from near Veracruz to Tampico, and is supporting scattered moderate to strong convection. Another surface trough analyzed along the eastern Yucatan Peninsula supports scattered moderate convection near the Yucatan Channel. Lastly, another surface trough extending off the southern FL Peninsula supports scattered moderate convection in the FL Straits.

For the forecast, a modest surface ridge will continue to support gentle to moderate E to SE winds over the eastern and north- central Gulf into early next week. A trough or weak low pressure center may emerge from the Yucatan Peninsula into the Bay of Campeche on Thu night and then track slowly northwestward through the weekend. It will enhance the gradient with the surface ridge, causing fresh to strong SE winds across the south-central and northwestward Gulf. It will also trigger scattered to numerous thunderstorms and rough seas across the west-central Gulf into Sun.

Caribbean Sea

At 1200 UTC, T.S. Cristina was located in the Eastern Pacific near the coast of El Salvador. A surface trough analyzed along the eastern Yucatan Peninsula is interacting with moisture from T.S. Cristina, and supports scattered moderate convection N of 15N and W of 80W to the coasts of Belize and Mexico, including the Gulf of Honduras. Scattered moderate convection is also ongoing in the SW Caribbean along the East Pacific monsoon trough. The pressure gradient between the Atlantic ridge and T.S. Cristina supports moderate to fresh winds with moderate seas from the central Caribbean to the northwest Caribbean. Winds are locally fresh to strong in the south-central Caribbean offshore Colombia, as well as in the Gulf of Honduras. Gentle to moderate trades and moderate seas prevail elsewhere.

For the forecast, the pressure gradient between the ridge of high pressure at the western Atlantic and T.S. Cristina in the Eastern Pacific offshore of El Salvador will sustain fresh to strong E to SE winds with moderate to rough seas from the south-central to northwestern Caribbean into early week. During the weekend, the high over the western Atlantic is expected to strengthen further, and cause fresh E trades to expand northward into the north- central basin.

Atlantic Ocean

A weak 1017 mb low at 25N64W and surface trough extending from 31N56W through the low to 22N67W are helping to develop scattered moderate convection from 22N to 28N between 60W and 65W. To the northwest, a weak cold front is analyzed along 28-29N between 60W and 79W. Another surface trough extending off the southern FL Peninsula supports scattered moderate convection in the waters SW of the Bahamas and the FL Straits. These features are also helping to maintain a weaker pressure gradient across much of the Atlantic N of 20N and W of 40W, where gentle to moderate trades and 3-6 ft seas prevail, except for 1-3 ft seas from the Bahamas to the FL Straits. Ridging from the Azores high expands across the rest of the Atlantic, supporting moderate to fresh trades and moderate seas across much of the basin S of 20N. Scatterometer data indicates fresh to strong NE winds and 6-9 ft seas across areas N of 20N and E of 40W, with the strongest winds occurring in between the Canary Islands.

For the forecast west of 55W, thunderstorms persist near a weak 1017 mb low pressure at 25N64W on the southern end of a surface trough extending to 31N56W. The low pressure will dissipate as it moves northeastward along the trough through Thu. Meanwhile, a weak frontal boundary currently between northeast Florida and Bermuda will shift northward Thu ahead of the weak low pressure. The Atlantic ridge will build across the region late Thu through Fri along roughly 25N. Looking ahead, this pattern will support moderate to fresh E to SE winds north of Hispaniola at night from Fri night through Sun night.

Posted 44 minutes ago by NHC Forecaster Adams