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000 AXNT20 KNHC 201207 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 805 AM EDT Mon Aug 20 2018 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 1145 UTC. ...TROPICAL WAVES... A far eastern Atlantic tropical wave has its axis along 32W/33W from 05N to 17N, moving westward at 10-15 kt. Isolated moderate convection is from 05N-17N. Scattered moderate convection is within 180 nm east of the wave from 05N-08N. Isolated showers and thunderstorms are elsewhere within 180 nm either side of the wave from 05N-11N. A central Atlantic tropical wave has its axis extending from 05N51W to 12N50.5W to 18N49W, moving westward at 10-15 kt. Isolated showers and thunderstorms are within 120 nm either side of the wave from 08N-11N. A Caribbean Sea tropical wave has its axis extending from far southern Costa Rica northward to 15N77W and to eastern Cuba near 20N76W. It is moving westward at 10-15 kt. Isolated moderate convection is within 60 nm east of the wave from 20N-21N. The northern portion of an eastern Pacific tropical wave extends along 91W northward to the far eastern Bay of Campeche, moving westward near 15 kt. Only isolated showers are noted within 60 nm of the wave. ...MONSOON TROUGH/ITCZ... The monsoon trough axis extends from western Africa at 13N17W to 10N28W to 08N40W, where scatterometer data indicates the ITCZ axis begins and extends to 08N49W where it briefly ends just east to the east of the central Atlantic tropical wave. It resumes at 09N52W to just inland the coast of S America at 07N58W. Scattered moderate convection is within 60 nm south of the axis between 17W-20W. Widely scattered moderate convection is seen from 05N- 09N between 26W- 29W. Isolated moderate convection is within 60 nm of the ITCZ axis between 53W-58W. ...DISCUSSION... GULF OF MEXICO... A 1023 mb high is centered over the W Atlantic at 32N59W, with a ridge axis extending WSW from the high to central Florida and to the eastern gulf waters. The associated gradient is allowing for generally moderate southerly flow to persist over much of the gulf, except for lighter SW to W flow, in the 5-10 kt range over the far northeastern gulf waters. Widely scattered moderate convection is over the N Florida Peninsula N of 27N. The northern portion of a tropical wave is over the eastern Bay of Campeche. No deep convection is occurring with this wave. See above for details. Scattered moderate to isolated strong convection is from 15N-21N between 92W-95W. An upper level low is centered over the Yucatan Channel near 22N86W enhancing the convection over western Cuba and the NW Caribbean Sea. Expect, a surface high to develop over the Gulf near 27N91W on Tue. This high will meander over the western gulf waters through Thu. A weak trough will stalls over the eastern Gulf waters, then drifts west and dissipates on Fri. CARIBBEAN SEA... Two tropical waves are over the Caribbean Sea and Central America. See above. Scattered moderate convection is noted over E Cuba, Panama, and Costa Rica. Similar convection is S of Puerto Rico from 15N-17N between 65W-68W. Otherwise, surface ridging extending from the Atlantic to the northern half of the basin support fresh to strong winds in the south-central Caribbean. Expect showers and convection to persist over the SW Caribbean for the next several days. Also expect strong to near gale force nocturnal easterly trades expected along the northwestern coast of Colombia and across the Gulf of Venezuela through the middle of the week. ATLANTIC OCEAN... A surface trough is N of the central Bahamas from 28N70W to 23N73W. Scattered showers are within 90 nm of the trough. A 1023 mb high is centered over the W Atlantic near 32N59W. Another surface trough is over the W Atlantic from 32N50W to 27N60W. Scattered showers are within 90 nm of this trough. A surface trough is analyzed along a position from near 28N69W to the southeastern Bahamas near 22N74W. A shortwave trough passing just to its northwest is providing additional atmospheric lift leading to clusters of scattered moderate convection from 26N-29N between 71W-74W. Isolated showers and thunderstorms are elsewhere within 90 nm of the surface trough from 22N to 26N. Scattered moderate convection is within 30 nm either side of a line from 09N58W to 11N61W. A 1026 mb high is centered over the Azores near 38N29W producing ridging and fair weather over the eastern Atlantic. The trough north of the central Bahamas is forecast to move westward across the Bahamas through Tue night. For additional information please visit http://www.hurricanes.gov/marine $$ Aguirre

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