AXNT20 KNHC 210003

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
703 PM EST Mon Nov 20 2017

Tropical Weather Discussion for North America, Central America Gulf of Mexico, Caribbean Sea, northern sections of South America, and Atlantic Ocean to the African coast from the Equator to 32N. The following information is based on satellite imagery, weather observations, radar and meteorological analysis.

Based on 1800 UTC surface analysis and satellite imagery through 2345 UTC.


The monsoon trough extends from the African coast near 10N15W to 08N18W to 07N21W. The Intertropical Convergence Zone axis extends from 07N21W to 06N35W to 05N52W. Scattered moderate convection is from 0N to 10N E of 36W.



A stationary front continues to weaken from the Straits of Florida SW to the southern-central Gulf of Mexico near 22N90W to the Bay of Campeche near 18N94W. Deep layer dry air prevails across the basin as indicated by CIRA LPW and GOES-16 water vapor imagery, which only allows for isolated showers within 75 nm either side of the front. Moderate northerlies are in the northern vicinity of the front while lighter easterlies to northeasterlies are elsewhere across the Gulf N of the front. Broken to overcast skies are in the NW Gulf associated with the remnants of a former surface trough. Radar data show isolated showers in that region. A surface trough, remnant of the front will develop later tonight. This trough will evolve to a center of low pressure over the NE basin Tuesday evening, which will support showers and tstms in the region as well as inland northern Florida.


CIRA LPW and GOES-16 water vapor imagery show deep layered dry air across the basin, except for the northern-central Caribbean where diffluent flow in the NE periphery of a ridge continue to support scattered showers and tstms. These showers cover the regions of the Windward Passage, Hispaniola and southern adjacent waters to 16N. Isolated showers are across Puerto Rico and Jamaica as well as the SE Caribbean, including the southern Windward Islands. In the central basin, just S of Jamaica, a 1008 mb low lacking convection is centered near 15N76W. The low will weaken in to a trough that will continue to move W the next two days. Showers across the north-central basin will shift towards the NE Caribbean tonight as the upper ridge moves E along northern S America.


Scattered to isolated showers prevail across the island and adjacent waters continuing through Tuesday morning. These showers will shift towards the NE Caribbean tonight as the upper ridge that supports it moves E along northern S America.


A cold front extends from 30N64W SW to 26N75W where it transitions to a dissipating stationary front that continues to the Florida Straits into the Bay of Campeche in the Gulf of Mexico. Ahead of the front, a surface trough extends from 25N64W to northern Dominican Republic supporting scattered to isolated showers S of 26N between 57W and 70W. A second cold front extends from 31N30W to 24N40W to 19N50W supporting scattered showers N of 24N between 22W and 39W. Otherwise, high pressure centered near 32N49W dominates the remainder central Atlantic.

For additional information please visit http://www.hurricanes.gov/marine

$$ Ramos