000 AXNT20 KNHC 151721 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 121 PM EDT Sat Apr 15 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 1715 UTC. ...SPECIAL FEATURE... Low pressure over the southwest north Atlantic near 22N64W will dissipate tonight as it moves northeast. The remnants of this low will then merge with another low pressure near 31N52W, which will also merge with a cold front racing towards the central Atlantic. Strong high pressure building behind the cold front will tighten the gradient, thus supporting gale force winds of 35 kt N of 30N between 43W-46W tonight. Please refer to the high seas forecast under AWIPS/WMO headers MIAHSFAT2/FZNT02 KNHC for more details. ...ITCZ/MONSOON TROUGH... The Monsoon Trough extends from the western Africa coast near 04N07W to 02N11W. The Intertropical Convergence Zone continues from 02N11W to 01N30W to the South American coast near 00N47W. Widely scattered moderate convection is from 00N-03N between 05W-11W. Scattered moderate to isolated strong convection is from 01S-2N between 44W-51W. ...DISCUSSION... ...THE GULF OF MEXICO... A 1031 mb high is centered over the W Atlantic near 39N69W producing surface ridging over the Gulf of Mexico. 10-20 kt SE flow is over the Gulf with strongest winds over the E Gulf where the surface pressure gradient is slightly tighter. An embedded surface trough is over the Bay of Campeche from 22N93W to 17N93W. The trough is void of precipitation. Elsewhere, radar imagery shows scattered showers over the SE Gulf to include the Straits of Florida. In the upper levels, a small trough is over the central Gulf with axis along 87W. Upper level diffluence E of the trough is enhancing cloudiness and showers over central Florida. Expect over the next 24 hours for convection over the SE Gulf to move to the central Gulf. CARIBBEAN SEA... 10-20 kt tradewinds are over the Caribbean Sea with the weakest winds over the Leeward Islands, and the strongest winds along the coast of Colombia. Scattered showers are over the Leeward Islands. Radar imagery confirms scattered showers S of Puerto Rico. Elsewhere, scattered showers are inland over N Colombia and NW Venezuela, Panama, Costa Rica, E Nicaragua, Honduras, E Guatemala, Belize, and central Cuba. In the upper levels, a broad ridge is over the Caribbean Sea. Broken high clouds covers the E Caribbean. Strong subsidence is over the NW Caribbean. Expect over the next 24 hours for the eastern and central Caribbean to have additional scattered showers. ...HISPANIOLA... Presently Hispaniola has fair weather. Expect over the next 24 hours for scattered showers to advect over the island from the east with the tradewind flow. ATLANTIC OCEAN... A cold front is over the W Atlantic from 31N57W to 26N69W. Scattered showers are within 60 nm of the front. A 1014 mb low is centered N of the Leeward Islands near 22N64W. Scattered showers are from 21N-23N between 60W-64W. A 1011 low is centered near 31N53W moving NE. A surface trough extends S from the low to 25N58W. Scattered moderate convection is from 26N-33N between 48W-54W. Gale conditions will be in vicinity of this low tonight. See above. A 1021 mb high is centered over the central Atlantic near 34N41W. The tail end of a stationary front is over the E Atlantic from 31N25W to 25N29W. This front is mostly void of precipitation S of 31N. Of note in the upper levels, an upper level trough is over the W Atlantic N of 20N between 50W-70W supporting the cold front. Expect the over the next 24 hours for the W Atlantic front to merge with the low near 31N53W and produce convection over the central Atlantic N of 20N between 40W-50W. For additional information please visit http://www.hurricanes.gov/marine $$ Formosa