000 AXNT20 KNHC 171029 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1205 UTC Mon May 17 2021 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 31N. The following information is based on satellite imagery, weather observations, radar and meteorological analysis. Based on 0600 UTC surface analysis and satellite imagery through 0930 UTC. ...SPECIAL FEATURES... ...ATLANTIC GALE WARNING... A 1003 mb low pressure center is located near 32N57W, just to the north of the area, and moving E-NE near 20 kt. Overnight ASCAT data shortly after 0000 UTC showed SW winds of 30-40 kt across the south semicircle of this low, that extended to 30N. Expect these gale-force SW to W winds to move along the northern boundary of the area between 55W and 58W through 1200 UTC before winds diminish to 25-30 kt there. Seas of , and sea heights ranging from 10 feet to 13 feet should be expected across this area. ...GALE-FORCE WIND WARNING OFF THE COAST OF MOROCCO... The surface pressure gradient, that is between high pressure that is between the Madeira Archipelago and the Azores Islands, and comparatively lower surface pressures in West Africa, will support developing gale-force winds in the METEO-FRANCE forecast area, that is called AGADIR. The gale-force winds are forecast to start at 17/1500 UTC, and end possibly at 18/0000 UTC. Seas are forecast to range from 9 to 12 feet. Please, refer to the Meteo- France High Seas Forecast, that is on the website: www.meteofrance.com/ previsions-meteo- marine/bulletin/grandlarge/metarea2, or the website: http://www.gmdss.org/bulletins/METAREA2.HIGH_SEAS_WARNING.1919.16 19193337429.html, for more details. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through the coastal plains of Guinea_Bissau near 11N15W to 06N20W. The ITCZ continues from 06N20W to 03N30W, to the Equator along 37W to the mouth of the Amazon River basin near 01S48W. Scattered moderate to strong convection is noted from 01N to 07N between 02W and 28W. Scattered moderate isolated strong convection is noted within 180 nm N of the ITCZ between 30W and 51W. GULF OF MEXICO... High pressure across the NE U.S. extends S-SW into the NE Gulf this morning, and supports moderate to fresh E to SE winds across the basin. This return flow across the NW Gulf is transporting abundant low level moisture into Texas, where a middle level trough is moving eastward across the state. Scattered strong thunderstorms have moved across SE Texas and are moving across SW Louisiana and the adjacent coastal waters north of 29N. This weather is expected to shift eastward today. Elsewhere upper level ridging and generally fair weather prevails across the basin. High pressure extending into the NE Gulf will remain generally stationary throughout the week. This will support moderate to fresh E to SE winds over the basin through Tue. Winds will increase to fresh to strong late Tue through Fri as low pressure deepens across the Southern Plains. CARIBBEAN SEA... Atlantic high pressure is centered across the NE Atlantic and extends W-SW and weakly across the W Atlantic north of the area. This is producing a modest pressure gradient, and supporting fresh to locally strong tradewinds across the southern Caribbean south of 15N between 64W and 77W, where seas are 5 to 7 ft. Stable atmospheric conditions associated with the western side of an upper level trough continue to produce generally fair weather east of 80W. A low to mid level trough to the south of 13N is moving across the Windward Islands this morning and will bring tropical moisture with scattered showers and a few thunderstorms across the SE Caribbean today and tonight. The monsoon trough passes through Colombia near 11N74W across Panama and into the eastern Pacific Ocean. Scattered moderate convection is noted south of 10N across the Gulf of Uraba and adjacent waters of Panama east of 79W. Atlc high pressure ridge NE of the area will shift eastward and weaken, diminishing winds and seas modestly across the basin through Wed. Trade winds will increase basin wide Wed night through Fri night as high pressure builds across the W Atlc. ATLANTIC OCEAN A cold front extends from the low pressure near 32N57W through 31N54w to 25N60W into the southern Bahamas, where it's remnants become a shearline across eastern Cuba. Scattered moderate convection is noted within 60 nm southeast of the front to the east of 60W, while scattered showers are seen elsewhere within 180 nm either side of the front to Cuba. Beyond the gale force SW winds mentioned above, W to SW winds of 20-30 kt prevail elsewhere south of the low to 27N between 50W and 60W. Seas across this area are 8 to 13 ft. To the NW of the front, moderate NE winds prevail within 240 nm north of the front and through the Bahamas and Straits of Florida, with gentle NE to E winds farther north. A surface ridge extends from a 1023 mb high pressure center near 34N22W to the waters north of Hispaniola. The pressure gradient to the south of the ridge is producing moderate to fresh tradewinds to the south of 19N, where seas are 5 to 7 ft. The weakening frontal boundary will drift SE and dissipate through late Tue. NE to E winds will become fresh to strong north of 23N and west of 68W late Tue through Fri as high pressure builds across the W Atlc. Seas will build 7 to 11 ft during this time to produce very rough marine conditions. $$ Stripling