000 AXNT20 KNHC 212359 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 659 PM EST Tue Feb 21 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. ...SPECIAL FEATURES... A 1010 mb surface low associated with an anomalously south deep-layer low is near 23N63W. A cold front extends from the low to 17N62W to 14N69W. These features are within a broad area of low pressure that prevails over the central Atlantic. A second cold front enters the area through 32N56W to 26N75W. This cold front will merge with the cold front previously described by tonight. The merged frontal boundary will then continue moving east enhancing winds/seas. A tight pressure gradient will become established between the front and a strong high pressure to its east, inducing gale-force winds north of 27N within 240 nm east of the front starting at 22/00Z. These winds are expected to lift north of the discussion by Wednesday night. See the latest NWS High Seas Forecast under AWIPS/WMO headers MIAHSFAT2/FZNT02 KNHC for more details. ...ITCZ/MONSOON TROUGH... The Monsoon Trough extends from the African coast near 08N14W to 03N19W. The Intertropical Convergence Zone extends from 03N19W to 00N46W. Isolated showers are observed along the ITCZ. ...DISCUSSION... GULF OF MEXICO... A cold front extends across the central Gulf from 30N87W to 18N94W. A squall line was analyzed ahead of the front from 30N86W to 28N87W. Scattered moderate convection prevails along these features mainly north of 26N. Scatterometer data depicts moderate to fresh northerly winds west of the front while gentle to moderate southerly winds prevail east to the front. A surface trough extends across the northwest Gulf from 30N94W to 28N94W with isolated showers and thunderstorms. Expect for the front to continue moving east through the next 24 hours. Latest guidance forecasts a surface low developing across the eastern Gulf tonight. The low will move east across the Florida Peninsula through Wednesday enhancing winds and convection. CARIBBEAN SEA... Overall, the Caribbean basin continues under fairly tranquil conditions at this time, with the exception of the northeastern waters. Isolated showers are observed over Cuba and its adjacent waters north of 18N. An area of low pressure centered N-NE of Puerto Rico extends a cold front that crosses the Lesser Antilles and eastern Caribbean waters from 17N62W to 14N68W. A a pre- frontal trough is also evident in observations across the Windward Islands from 16N61W to 13N63W. Isolated showers are observed along these features. Scatterometer data depicts gentle to moderate northeasterly trades across most of the basin mainly west of 70W. Moderate northerly winds are prevailing north of the front affecting the waters north of 15N between 60W-70W. Light to moderate southerly winds prevail south of the front and east of 70W. Expect during the next 24 hours for the cold front currently over the Gulf of Mexico to enter the west Caribbean enhancing winds/convection. The frontal boundary over the east Caribbean will continue moving east while weakening. ...HISPANIOLA... Fair weather prevails across the island at this time. Patches of low-level moisture moving southward due to northerly flow to the west of the Atlantic low pressure system and cold front, will approach the north coast of the island tonight increasing the chance for precipitation. Any shower activity that approaches the north coast will be moving rather quickly to the south. ATLANTIC OCEAN... Scattered showers prevail across the west Atlantic mainly west of 74W. To the east, a cold front extends from 31N57W to 26N75W. No significant convection is related to this front at this time. A 1010 mb low is centered near 23N63W, with a cold front extending south-southwest across the Lesser Antilles and eastern Caribbean. An area of scattered showers prevails to the east of these features affecting the waters between 48W-56W. Expect for the cold fronts to merge near 60W tonight. Gale-force winds are expected to develop near the new front. Please refer to the section above for details. For additional information please visit http://www.hurricanes.gov/marine $$ ERA