AXNT20 KNHC 181714

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1214 PM EST Sat Nov 18 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 1200 UTC surface analysis and satellite imagery through 1615 UTC.


A cold front will reach the NW Gulf of Mexico tonight and will move across the remainder of the Gulf through Monday. Strong high pressure building behind the front will produce gale force winds over the SW Gulf S of 25N to the west of the cold front beginning 1200 UTC Sunday and persisting through Sunday night. See the latest high seas forecast under AWIPS/WMO headers HSFAT2/FZNT02 for more details.


The monsoon trough extends from the African coast near 09N13W to 07N21W. The Intertropical Convergence Zone axis extends from 07N21W to 06N24W to 07N34W, then resumes west of a surface trough near 09N43W to the South American coast near 09N61W.



A ridge axis extends across the eastern Gulf from high pressure centered over the SE US Atlantic Coast. This ridge supports gentle winds over the eastern gulf, and moderate to fresh winds over the remainder of the Gulf. The basin is currently void of convection. A cold front will reach the NW Gulf tonight and will sweep across the Gulf through Monday. Gale force winds are expected over a portion of the SW Gulf Sunday into Sunday night behind the front. Please refer to the special features section for more details on this gale.


A surface trough extends from Hispaniola at 18N73W to a 1008 mb low near 11N75W and then southward over Colombia. Due to an upper trough to the west, scattered moderate convection is offset to the east of these surface features, and is occurring within 240 nm E of a line from 19N71W to 11N74W. High pressure over the western Atlantic is supporting moderate to fresh NE winds over the northwestern Caribbean. Mainly gentle to moderate winds cover the remainder of the Caribbean. Over the next 24 hours the low and trough will drift northeastward with convection continuing to the east of the trough.


Scattered showers are over the western half of the island as moisture continues to get pulled across the region, due to an upper trough to the west. This pattern will continue through Sunday, with localized flooding possible during this time.


High pressure centered near the SE US coast dominates the Atlantic waters west of 70W. A 1010 mb low is centered near 31N40W with a stationary front extending from this low to 27N47W to a 1008 mb low near 27N56W. A surface trough extends from this low to near 20N69W. Another surface trough is just to the east and extends from 22N62W to 19N67W. These features are supporting a large area of showers and embedded areas of steady rainfall with isolated thunderstorms within 600 nm E of a line from 31N57W to 20N70W. High pressure of 1019 mb centered near 28N28W dominates the eastern Atlantic. Over the next 24 hours the lows will move NE with convection spreading east. SW winds will increase to 20 to 25 kt N of 30N east of 70W Sunday as a cold front approaches the region.

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

$$ Latto