000 AXNT20 KNHC 200953 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1205 UTC Fri May 20 2022 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 0950 UTC. ...SPECIAL FEATURES... A Central American Gyre (CAG) is developing across Central America and the adjacent southwest Caribbean this morning. The monsoon trough has begun to shift northward, increasing SW winds and advecting tropical moisture over Central America. Heavy rainfall has begun in the SW Caribbean and portions of Nicaragua, Guatemala and Honduras. Extreme rainfall is possible across the Pacific coasts of Central America, and also over southern Honduras and northeast Nicaragua. There is potential for flash flooding and mudslides, especially across mountainous terrain. This event is expected to last through early next week. Please refer to products issued by your local weather service for more information. ...TROPICAL WAVES... A tropical wave is in the Atlantic with axis along 45W, from 02N to 11N moving west at 20 kt. Scattered moderate convection is noted from 03N to 07N between 44W and 53W. A tropical wave is in the far western Caribbean with axis S of 18N along 87W, moving west at 10 kt. A line of moderate convection behind the tropical wave, associated partly with the CAG, extends across the SW Caribbean from 16N83W to 10N76W ...MONSOON TROUGH/ITCZ... The monsoon trough extends from the African coast near 11N15W to 07N18W. The ITCZ continues from 06N20W to 00N42W. Scattered moderate to strong convection is noted in the eastern Atlantic from 03N to 08N between 10W and 30W. ...GULF OF MEXICO... The gradient between surface ridging from the Atlantic and lower pressure over Mexico is supporting moderate to fresh SE flow across the majority of the basin. Seas are 1-3 ft in the eastern Gulf, 4-6 ft in the NW Gulf and 3-5 ft elsewhere. For the forecast, high pressure will build over the western Atlantic through Sun as low pressure develops over the Bay of Campeche. This pattern will allow an area of moderate to fresh southeast winds over the western Gulf to expand eastward tonight into Sat. From Sat-Sun fresh to strong SE winds will dominate the Yucatan Channel, central and NW Gulf. Winds and seas will then diminish slightly across most of the basin Sun into Mon as the pressure gradient relaxes, leaving only pulses of fresh to occasionally strong winds at night off the northern and western Yucatan Peninsula. Fresh SE winds may return to the western Gulf by Tue as a trough deepens over the southwest Gulf. ...CARIBBEAN SEA... Please see the Special Features section for information on a potential heavy rainfall event. Surface ridging over the western Atlantic along 26N is supporting moderate to fresh trade winds across the east and central Caribbean, with fresh to strong winds in the south-central Caribbean. Seas are 5-7 ft in these regions, except 7-9 in the south-central Caribbean. Winds are gentle in the SW Caribbean with 2-4 ft seas. Winds are moderate to fresh in the NW Caribbean with 4-6 ft seas. For the forecast, winds and seas across the basin will increase tonight into the weekend as the western Atlantic ridge strengthens and broad low pressure over Central America gradually shifts west to northwestward. The strongest winds and highest seas are expected over parts of the northwestern and south-central Caribbean during this period. Looking ahead, winds and seas will start to diminish across the basin early next week as the pressure gradient relaxes. ...ATLANTIC OCEAN... An abundance of tropical moisture is causing scattered moderate convection across the NW Bahamas. A surface ridge along 26N covers the western basin , supporting mainly light to gentle anticyclonic winds, except for moderate S winds along NE FL and moderate SE winds north of Hispaniola. Trade winds increase to moderate south of 17N. High pressure dominates the central Atlantic, with light to gentle winds north of 20N and gentle to moderate winds south of 20N. In the eastern Atlantic, moderate to locally fresh N-NE winds are observed within 500 nm of the African continent. Seas are slight in the western Atlantic north of 24N and west of 65W. Seas are generally moderate elsewhere. For the forecast west of 55W, a surface ridge along 26N will lift north to 30N through tonight and strengthen. This pattern will support mainly gentle to moderate breezes across the region through early next week, except for moderate to fresh winds north of Hispaniola starting tonight. $$ Flynn