000 AXNT20 KNHC 202248 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0005 UTC Sat May 21 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 1800 UTC surface analysis and satellite imagery through 2140 UTC. ...SPECIAL FEATURES... A broad area of low pressure, known as the Central American Gyre (CAG), is developing across Central America and the adjacent southwest Caribbean today. The monsoon trough has begun to shift northward across the tropical northeast Pacific, increasing SW winds and advecting tropical moisture over Central America. Heavy to extreme rainfall is possible over portions of Guatemala, El Salvador, Nicaragua, Honduras, Costa Rica, and Panama. 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 51W, from 01N to 14N moving west around 20-25 kt. Scattered moderate isolated strong convection is noted from 00N-07N between 44W-54W. A tropical wave is exiting the far western Caribbean with axis south of 19N along 89W and across Central America, moving west around 10 kt. Associated convection is occurring over land near the wave at this time, and extends across the adjacent Pacific waters. Scattered moderate isolated strong convection is noted behind the wave from 14N-16.5N between 80W-84W. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from the African coast near 14N16W to 07N21W. The ITCZ continues from 07N21W to 02N45W. Scattered to numerous moderate to strong convection is noted from 04N-09W east of 25W. Scattered moderate isolated strong convection is noted south of 07N between 44W-54W. The eastern North Pacific's monsoon trough extends across Central America, along the border of Costa Rica and Nicaragua, and extends to 11N75W along the coast of Colombia. Widely scattered moderate convection is noted south of 14N west of 76W. ...GULF OF MEXICO... The gradient between the Bermuda High and lower pressure over NE Mexico is supporting moderate to fresh S to SE flow across the majority of the basin, with strong winds occurring along the SE Texas coast. Seas are 2-4 ft in the eastern Gulf and 4-7 ft in the western Gulf. Low level moisture has moved from the southeast Gulf this morning to offshore of central Florida, where divergent upper-level flow is supporting scattered moderate convection from 26.5N-28N and east of 85W. Otherwise, clear to mostly fair skies prevail across the basin. Smoke from seasonal agricultural fires over Mexico continues to spread northward and is producing hazy skies across the western two-thirds of the basin. For the forecast, high pressure will build over the western Atlantic through Sun as low pressure develops over Central America and the Bay of Campeche. This will allow for mostly fresh southeast winds over the western Gulf to expand eastward tonight into Sat. Fresh to strong southeast winds from the northwestern Caribbean Sea will surge into the central Gulf waters and Yucatan Channel from from Sat through Sun, diminishing to fresh speeds Sun night. Elsewhere, 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 return flow is expected over the western Gulf Mon night through Tue night. ...CARIBBEAN SEA... Please see the Special Features section for information on a potential heavy rainfall event associated with a Central American Gyre (CAG). The Bermuda High is interacting with lower pressure over Central America, associated with the developing Central American Gyre, and is forcing fresh to strong E to SE trades over the central and W Caribbean with moderate to fresh trades over the E Caribbean. Seas are 7-10 ft over the central Caribbean, 5-7 ft over the W Caribbean, and 4-6 ft over the E Caribbean. Scattered moderate and isolated strong convection is noted from 26.5N-28N and east of 85W in association with a tropical wave and the developing Central American Gyre. Mostly fair and hazy skies prevail elsewhere east of 75W as Saharan Air and areas of suspended dust have moved into the basin behind the tropical wave. 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 to be 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... Ridging associated with the Bermuda and Azores Highs stretches across the basin along 29N-32N. Winds north of a line from 26N30W to 21N57W to 28N80W are gentle or weaker with seas 3-5 ft. South of the line and east of 60W, the NE to E trades are moderate to fresh and with seas 5-8 ft. Saharan Air and suspended dust dominate much of this area producing hazy skies. West of 60W, moderate SE to S winds prevail with seas 2-4 ft. Southerly low level flow across the far eastern Gulf of Mexico, Florida and the Bahamas has advected moisture northward this afternoon, and has erupted into scattered moderate to strong convection from 24N- 29N west of 71W, and supported by upper-level divergent flow. For the forecast west of 55W, a surface ridge along about 28N 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. $$ Stripling