Tropical Waves

The axis of a tropical wave is along 35W, to the south of 12N, moving west at 10 kt. Scattered showers and isolated thunderstorms are observed from 04-07N between 35-40W.

Monsoon Trough/ITCZ

The monsoon trough exits the coast of western Africa near 15N17W and extends southwestward to near 05.5N22W. The ITCZ extends from 05.5N22W to 05N33W, where it is broken by a tropical wave. The ITCZ then resumes at 4.5N37W and extends southwestward to the coast of Brazil near 1.5N50W. Aside from the convection associated with the tropical wave, numerous moderate and isolated strong convection is observed from 02-11N between 10-30W. More scattered showers and isolated thunderstorms are observed from 00-07N between 45-52W.

The East Pacific monsoon trough extends into the far SW Caribbean reaching the Colombian Low. Scattered moderate and isolated strong convection is seen over the far SW Caribbean S of 12.5N.

Gulf Of America

A cold front extends from near Tampa Bay WNW to near 28.5N88W where it becomes a stationary front, with the stationary front then extending to the coastal border of Texas and Louisiana. A pre-frontal trough is analyzed from 29N91W to 27N96W to 23N97W to the SW Bay of Campeche. These features are supporting scattered showers and isolated thunderstorms across much of the Gulf N of 26N. The diurnal surface trough originating from the Yucatan is analyzed from 25N91W to the Mexican coast near 18N93W. This trough as well as the previously mentioned trough are supporting scattered showers across the Gulf S of 26N and W of 88W. Moderate to locally fresh winds are seen from 88W to the diurnal Yucatan trough and S of 24N, with moderate or weaker winds elsewhere across the Gulf. Slight seas prevail across the basin. Smoke from agricultural fires in southeastern Mexico continues to maintain hazy sky conditions across the Bay of Campeche and western Gulf this morning and afternoon.

For the forecast, a slowly moving front extending W to E over the northern Gulf coastal waters will sink southward across the NE Gulf today, then stall and dissipate tonight. High pressure will develop across the NE Gulf in the wake of this front and dominate the basin through Sun, before Atlantic high pressure builds into the Gulf Sun night and Mon and strengthens the ridge. Gentle to moderate winds will freshen in the western Gulf starting Fri night. E winds will pulse fresh to locally strong along and just north of the Yucatan Peninsula each afternoon and evening through the period as a trough develops daily and drifts westward at night. Smoke from agricultural fires in southeastern Mexico are expected to maintain hazy sky conditions across the Bay of Campeche and western Gulf through the period.

Caribbean Sea

The pressure gradient between a weak 1017 mb high north of the area and the Colombia Low is supporting fresh to strong E winds in the central and SW Caribbean, generally S of 17N between 70-80W, where seas are 6-9 ft. Moderate to fresh trades prevail across the remainder of the eastern, central, and SW Caribbean as well as the Gulf of Honduras, where seas are 3-6 ft. Moderate or weaker trades and seas of 2-5 ft prevail elsewhere. Please see the Monsoon Trough/ITCZ section for details on convection in the basin.

For the forecast, weak high pressure prevails across the Atlantic along 25N tonight between the Bahamas and 60W and will shift NE through tonight. High pressure across the NE Atlantic will gradually build westward along 25N and into the Bahamas Fri through the weekend, which will strengthen the ridge. This pattern will support fresh to strong trade winds south of 15N through the upcoming weekend, gradually expanding westward to Nicaragua. Winds will pulse to fresh to strong across the Gulf of Honduras each evening and night through the period. Moderate trades in the eastern Caribbean and tropical Atlantic will freshen Thu night into the weekend, with large swell over the Atlantic waters east of the Windward Islands starting Sat.

Atlantic Ocean

A cold front enters the discussion waters near 31N48W and extends southwestward to 24N59W. A few showers are noted along the front. Moderate to fresh S to SE winds extend out ahead of the front to about 44W and N of 29N. Seas in this area are 6-8 ft. Another cold front has entered the waters off the SE US coast near 31N76W and extends southwestward to the Florida coast near Cape Canaveral. A pre-frontal trough is also analyzed from 30.5N75.5W to 24N81W. Scattered showers and isolated thunderstorms are seen ahead of the pre-frontal trough out to about 72W and N of 26N. Moderate to fresh SW winds are seen ahead of the trough to about 68W and N of 28N, with seas of 4-6 ft in this area.

Elsewhere across the Atlantic, convergent surface winds are aiding in the development of widely scattered showers and thunderstorms in two areas: one from 16-25N between 36-53W, and the other off the northern coasts of Guyana and Venezuela. Otherwise, a 1032 mb high centered near the Azores extends a ridge across much of the subtropical and tropical Atlantic away from the aforementioned frontal boundaries. Recent scatterometer data indicate fresh to strong NE winds and seas of 6-8 ft ongoing off the coast of Morocco as well as through the Canary Islands, generally N of 20N and E of 20W. Moderate to fresh trades and seas of 4-7 ft prevail across much of the Atlantic S of 20N, as well as from 20-31N between 20-40W. The remainder of the Atlantic N of 20N and W of 40W away from the frontal boundaries is seeing moderate or weaker winds and seas of 2-5 ft prevail.

A plume of Saharan Dust continues to be very evident over the E Atlantic on satellite imagery. Lofted dust is observed across a large region from 05-23N and E of 38W, with the highest dust concentrations noted E of 25W.

For the forecast west of 55W, a surface ridge along 25N will shift eastward through late today ahead of a cold front moving off the coast of Florida. The front will stall and dissipate across the northern Bahamas overnight, as the subtropical ridge builds westward along 26N-27N into the region. The resultant pressure gradient south of the strengthened ridge will support fresh winds south of 22N, mainly along the northern coast of Hispaniola through early next week. A series of weak frontal troughs will sweep eastward across the waters N of 28N through the period.

Posted 4 hours ago by NHC Forecaster Adams