HURRICANES

Special Features

Atlantic Gale Warning: A deep-layered upper trough extending across the W Atlantic and into the W Caribbean will aid in strengthening of a low pressure currently located near 29N59W. This system will move NE and exit the forecast waters Wed morning. Strong to minimal gale-force SW winds are expected ahead of this low pres this evening and tonight. Seas are forecast to build to 10 or 11 ft within these winds.

Please read the latest HIGH SEAS FORECAST issued by National Hurricane Center at web-site https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml for more details.

Heavy Rainfall in Hispaniola, Jamaica, and Eastern Cuba: A persistent upper-level trough over the western Caribbean will sustain a diffluent pattern aloft across the area through Friday. This will support the generation of strong thunderstorms capable of producing dangerous lightning, heavy rain, and gusty winds through Friday. Heavy rain can lead to flash flooding and mudslides, especially in areas of Hispaniola where the ground remains saturated from recent heavy rain events. Latest model guidance indicates that the most significant precipitation are expected over north-central Dominican Republic. There are also indications that significant rainfall could occur over parts of east and central Cuba where abundant moisture will linger through the rest of the work-week. The rainfall over Hispaniola and Cuba will be heavily influenced by diurnal heating and the local and effects. As a result, the heaviest rainfall will occur in the afternoon and evening hours each day. Please refer to products from your local weather service for more information.

Tropical Waves

A far eastern Atlantic tropical wave is near 27W from 11N southward, and moving west at 10 kt. Scattered moderate convection is noted where the wave meets the ITCZ from 03N to 07N between 25W and 31W.

A second tropical wave is near 38W from 11N southward, and moving west at 10 kt. Scattered moderate convection is near the southern end of the wave axis from 03N to 07N between 36W and 40W.

Another Atlantic tropical wave is near 55W from 12N southward to Suriname, moving west near 10 kt. Scattered moderate convection is behind the wave axis from 05N to 08N between 50W and 55W.

Monsoon Trough/ITCZ

A monsoon trough enters the Atlantic near 12N15W then continues southwestward to 05N26W. The ITCZ extends from 05N26W to 05N36W to 05N52W. Aside from the convection associated with the tropical waves, scattered moderate convection can be found from 08N to 11N between 15W and 20W, from 05N to 10N between 20W and 24W, and from 04N to 08N between 40W and 50W.

The eastern end of the East Pacific monsoon trough is generating scattered moderate to isolated strong convection over parts of Panama and regional waters, particularly S of 12N between 76W and 80W.

Gulf Of Mexico

High pressure of 1017 mb located near 31N72W extends a ridge across Florida into the Gulf of Mexico. The pressure gradient between the ridge and lower pressures over Texas and Mexico is resulting in moderate to fresh SE winds and seas of 4 to 7 ft over the western Gulf, and gentle to moderate SE winds and 1 to 3 ft seas over the eastern Gulf. Hazy conditions due to agricultural fires in southern Mexico persist across most of the western Gulf, including the Bay of Campeche, where medium concentration of smoke is noted on the smoke graphic recently issued by SAB.

For the forecast, a weak Atlantic ridge extends SW into the NE Gulf, and will dominate the basin through the next several days. This pattern will support generally moderate to fresh SE to S winds in the western Gulf, fresh to occasionally strong near the Yucatan Peninsula and in the NW Gulf, and gentle to moderate winds in the eastern Gulf through late Wed. By Thu, the ridge will weaken, allowing for winds to diminish somewhat into the weekend. Hazy conditions due to agricultural fires over Central America and Mexico will continue for the next couple of days, reducing visibility to around 3 nm at times, mainly over the western half of the Gulf.

Caribbean Sea

Please read the Special Features section above for information on a heavy rainfall event.

As previously mentioned, a persistent upper-level trough is helping to induce numerous showers and thunderstorms over Hispaniola, Jamaica and eastern Cuba, including also the Windward Passage and the regional waters between Haiti and Jamaica. Scattered showers and thunderstorms are noted over the Lesser Antilles in a SE wind flow.

The most recent scatterometer data indicate fresh to locally strong SE winds over the eastern Caribbean where seas are 5 to 7 ft based on altimeter data. Elsewhere, mainly gentle to moderate winds are observed with seas of 3 to 5 ft over the central part of the basin, and 1 to 3 ft over the NW Caribbean.

For the forecast, weak high pressure extends across the western Atlantic along 31N-32N. A deep layered upper-level trough from the W Atlantic to the W Caribbean will continue to support active thunderstorms across north-central portions through this evening. As this feature moves E-NE across the Atlantic, associated weather will shift across the NE Caribbean this evening through Thu. Fresh trade winds will return to southeast portions of the basin Thu through Fri then shift into south central portions through the weekend, as high pressure builds across the western Atlantic.

Atlantic Ocean

A Gale Warning is in effect for the Atlantic. Please read the Special Features section above for more information.

A cold front enters the forecast region near 31N36W then continues westward to near 28N50W. A surface trough extends from 28N50W to to a 1011 mb low pressure located near 29N59W to 25N70W to eastern Cuba. A large area of showers and thunderstorms is S and E of the trough affecting mainly the waters N of 19N and W of 55W to the trough axis. Winds and seas could be higher near tstms. Divergent flow aloft is supporting this convective activity. High pressure of 1017 mb located near 31N72W dominates the remainder of the western Atlantic W of the above mentioned trough. Another high pressure system located over the central Atlantic is in control of the weather pattern across the rest of the forecast waters. Gentle to moderate anticyclonic flow is noted E of 55W while moderate to fresh trades are blowing across the tropical Atlantic. Seas are generally 4 to 7 ft.

For the forecast W of 55W, a deep-layered upper trough across the W Atlantic and into the W Caribbean will shift E-NE across the region through Thu, and maintain active thunderstorms between 55W and 70W, that will shift E and NE ahead of the trough. The feature will also aid in strengthening of the low pressure, which will move NE and exit the area waters Wed morning. Strong to minimal gale-force SW winds are expected ahead of this low pres this evening as it moves across the NE waters. Weak high pressure will begin to build across the basin Wed then shift slowly E-NE Thu through Fri night. A weak front will move into the far NW waters Sat and stall there Sun.

Posted 1 hour, 18 minutes ago by NHC Forecaster Gr