000 AXNT20 KNHC 201030 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 530 AM 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 0600 UTC surface analysis and satellite imagery through 1015 UTC. ...SPECIAL FEATURE... Strong high pressure behind a cold front over the Gulf of Mexico is supporting gale force winds S of 21N W of the front. These winds are forecast to continue through Monday morning. Wave heights of 8 to 12 ft are expected associated with these winds. See the latest high seas forecast under AWIPS/WMO headers HSFAT2/FZNT02 for more details. ...ITCZ/MONSOON TROUGH... The monsoon trough extends from the African coast near 09N13W to 07N20W. The Intertropical Convergence Zone axis extends from 07N20W to 06N34W to 08N42W to the South American coast near 07N58W. Scattered moderate to isolated strong convection is from 03N-08N between 10W-30W. Isolated moderate convection is from 08N-12N between 33W-40W. ...DISCUSSION... GULF OF MEXICO... As of 0900 UTC, a cold front extends from S Florida near 26N80W to 23N88W. A stationary front continues to 21N94W to the Bay of Campeche near 18N94W. Scattered showers are within 15 nm of the front. A gale is over the SW Gulf S of 21N within 60 nm of the coast of Mexico. See above. 15-25 kt N winds are over the remainder of the Gulf. In the upper levels, zonal flow is noted. Strong subsidence is over the Gulf except along the Texas and Louisiana coasts. Expect over the next 24 hours for the front to stall from S Florida to the SW Bay of Campeche, and then begin to slowly retrograde back N. CARIBBEAN SEA... A 1008 mb low is centered over the central Caribbean near 15N73W. A surface trough extends NE from the low through the Mona Passage to the Atlantic near 23N66W. Scattered moderate convection is near the low from 12N-18N between 68W-71W, to include Aruba and Curacao. Scattered showers are elsewhere within 180 nm of the trough axis, to include Puerto Rico and the Virgin Islands. In the upper levels, an upper level trough is over the NW Caribbean with axis from E Cuba near 20N74W to the Gulf of Honduras near 16N89W. Upper level diffluence E of the trough is enhancing the showers and convection over the central Caribbean Sea. Expect the area of convection to drift W and persist for the next 24 hours. ...HISPANIOLA... Scattered showers are over Hispaniola, and will continue through Tuesday. Expect convection to build over Hispaniola in the afternoon and evening hours during maximum heating. Localized flooding is also possible during this time. ATLANTIC OCEAN... As of 0900 UTC, a cold front is over the W Atlantic from 31N72W to near Homestead Florida at 26N80W. Scattered showers are within 60 nm of the front. A 1020 mb high is centered over the central Atlantic near 32N50W producing fair weather. A cold front is over the E Atlantic from 31N32W to 26N40W to 21N54W. Isolated moderate convection is within 120 nm of the front. A surface trough is just E of the Canary Islands from 30N12W to 25N16W. Scattered showers are over the Canary Islands. Of note in the upper levels, an upper level trough is over the W Atlantic enhancing the W Atlantic front. Another upper level trough is over the central Atlantic with axis from 31N46W to 23N53W. Upper level diffluence is E of this trough. In addition, a small upper level low is centered near the Canary Islands at 30N13W. For additional information please visit http://www.hurricanes.gov/marine $$ Formosa