Special Features

Heavy Precipitation in South Central America and Colombia: Two tropical waves will propagate into Central America over the next several days. The waves will interact with enhanced divergence aloft and an active monsoon trough. The first wave is located near 88W. As this wave continues westward, expect heavy precipitation to continue in Costa Rica, the Darien region of Panama and into Choco-Colombia into Sun. The second tropical wave will enter the western Caribbean tonight into Mon and strengthen the cyclonic rotation over Panama and Colombia, which will favor an increase in available moisture into Colombia and moist easterly flow into the eastern portion of Costa Rica. The heaviest precipitation is expected in Costa Rica through this morning, while the heaviest precipitation is expected in southwest Panama, the Darien Region, and Choco-Colombia late today into Monday. There is some uncertainty on how far south the heaviest rainfall could reach, particularly due to how far south the available moisture and the westerly flow enters the region.

Please refer to the WPC International Desk and local weather services for more information.

Tropical Waves

A tropical wave is west of the Cape Verde Islands extending from 07N to 19N with axis near 31W, moving west at 15 kt. Scattered moderate convection is from 09N to 15N between 25W and 37W.

A tropical wave is over the central waters, extending from 04N to 20N with axis near 47W, moving west at 15-20 kt. Scattered moderate convection is from 09N to 14N between 46W and 52W.

A tropical wave is over the central Caribbean with axis near 69W south of 20N, moving westward at 15-20 kt. Numerous moderate tothe approaches to the Windward Passagestrong convection is from 12N to 19N between 66W and 73W.

Monsoon Trough/ITCZ

The monsoon trough enters the Atlantic near 17N16W, and extends southwestward to 11N30W to 10N41W. The ITCZ begins near 09N48W and continues to 07N58W. Aside from the convection discussed in the Tropical Waves section above, scattered moderate convection is offshore W Africa from 06N to 14N between 11W and 20W.

Gulf Of America

A 1021 mb high is over the Florida Panhandle coastal waters extending a ridge axis southward to 23N. A generally weak pressure gradient supports light to gentle variable winds and slight seas N of 23N. Over the SW Gulf, a surface trough moves across the Bay of Campeche enhancing winds to moderate speeds and building seas from slight to moderate. Scattered showers are offshore Veracruz, ahead of the trough.

For the forecast, a center of high pressure will remain over the north-central Gulf through Mon, then moves toward the SE Gulf by Tue while weakening some. This pattern will continue to support mostly gentle to moderate E to SE winds across the basin, with pulses of fresh winds occurring north and west of the Yucatan Peninsula and into the Bay of Campeche each night, as a surface trough migrates from the Yucatan Peninsula westward across the SW Gulf. Slight to moderate seas are expected through the forecast period.

Caribbean Sea

The main feature over the basin is a tropical wave moving across Hispaniola and central Caribbean this morning, which is bringging strong winds, rough seas and heavy showers to this region. Scattered moderate convection is across the Costa Rica and Panama offshores associated with the eastern extension of the E Pacific monsoon. Fresh to strong trade winds are across much of the basin along with moderate to rough seas, except for moderate to fresh NE to E winds over the NW Caribbean where seas are moderate. This is due to a relatively strong gradient of pressure over the region influenced by high pressure E of the Bahamas. This is also accelerating the winds across the Windward Passage to strong speeds, which has built seas to 9 ft.

For the forecast, surface ridging N of the area combined with the Colombian low will continue to support fresh to strong winds over most of the east, central and SW Caribbean through this evening. A strong tropical wave, with axis near 68W, will impact the central Caribbean today through Mon. Fresh to strong winds, moderate to rough seas and locally heavy rain will be associated with the wave, forecast to reach the western part of the basin Mon night into Tue. Another tropical wave will approach the Leeward Islands by Tue.

Atlantic Ocean

The subtropical Atlantic waters remain under the influence of the Bermuda-Azores High, which is supporting mainly moderate or weaker winds, except across the Great Bahama Bank, the approaches to the Windward Passage, and the adjacent waters of Puerto Rico and Hispaniola S of 23N where winds are moderate to fresh from the E, except locally strong in the the approaches to the Windward Passage. Moderate to fresh SW to W winds are also ongoing over the NE offshore waters N of 28N and E of 74W ahead of an approaching cold front which is also generating scattered showers and tstms over this region. Moderate seas are across the western, central and eastern subtropical Atlantic waters.

For the forecast west of 55W, the Bermuda-Azores High, combined with the passage of a tropical wave through the Caribbean Sea will cause fresh to strong NE to E winds south of 22N including the approaches and in the Windward Passage through tonight. Looking ahead, a cold front will slowly push across the northern forecast border east of 70W late today, and move across the northern forecast waters on Mon while dissipating into a trough by Tue. Fresh to strong SW to W winds are expected ahead of the front and E of 70W today and tonight.

Posted 53 minutes ago by NHC Forecaster Ramos