000 AXNT20 KNHC 221701 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1805 UTC Sun Sep 22 2024 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 1200 UTC surface analysis and satellite imagery through 1636 UTC. ...SPECIAL FEATURES... Potential Heavy Rainfall in Central America: A Central American Gyre (CAG) is gradually developing over Central America with a broad 1008 mb low pressure near Nicaragua. Numerous moderate to isolated strong convection encompasses much of the W Caribbean Sea in association with this low. The low is forecast to drift northwestward across northern Costa Rica, Nicaragua, Honduras, and the Yucatan Peninsula through the middle of next week. Aided by abundant tropical moisture, this system may produce significant rainfall over Costa Rica and eastern Nicaragua through Tuesday. Heavy rain will likely spread over central and northern Guatemala, western Honduras, Belize and the eastern Yucatan Peninsula Sunday evening through Thursday. This will lead to an increased potential for life- threatening flash flooding and mudslides in these areas. In addition, gradual development of this system is expected, and a tropical depression is likely for form as the system moves slowly north across the NW Caribbean and Gulf of Mexico through the end of the week. There is a high chance of tropical cyclone formation in the next seven days. It is recommended that residents in the aforementioned areas stay alert on the latest information from their local meteorological agencies. Please refer to the Tropical Weather Discussion for the Eastern Pacific at website: www.hurricanes.gov/text/MIATWDEP.shtml for rainfall across El Salvador and the Pacific coasts of Nicaragua, Guatemala, and southern Mexico. ...TROPICAL WAVES... A new tropical wave has been analyzed along 42W from 04N to 17N. Scattered moderate convection is depicted from 13N to 20N between the wave axis and 45.5W. A new tropical wave has emerged off the coast of West Africa and is analyzed along 17.5W from 06.5N to 19N. Scattered moderate to isolated strong convection is depicted from 10N to 18N between the west coast of Africa and 22W. As this waves moves westward during the next several days, environmental conditions could support some gradual development of this system, and a tropical depression could form during the middle to latter part of the week while the wave moves westward across the eastern and central tropical Atlantic. This wave has a medium chance of tropical cyclone formation in the next 7 days. ...MONSOON TROUGH/ITCZ... A monsoon trough enters the Atlantic near12N16W, then extends southwestward across 10N24W to 07N36W. An ITCZ curves northwestward from 07N36W to 08N40W and from 11N48W to 11N55W. No significant convection is depicted in associated with the monsoon trough or the ITCZ at this time. See Special Features section above for information on a low pressure center along the eastern end of the East Pacific monsoon trough and its associated convection. ...GULF OF MEXICO... See Special Features section above for information on developing low pressure over the NW Caribbean and adjacent parts of Central America that may impact portions of Gulf of Mexico later this week. Weak high pressure dominates, aside from a surface trough that has moved W offshore the Yucatan this morning. Dry conditions prevail with light to gentle E winds and seas of 3 ft or less. For the forecast, a broad area of low pressure is over the NW Caribbean Sea and adjacent parts of Central America. Environmental conditions appear favorable for gradual development of this system during the next several days. A tropical depression is likely to form while the system moves slowly northward across the northwestern Caribbean Sea and Gulf of Mexico through the end of the week. There is a high chance of tropical cyclone formation in the next seven days. Regardless of development, winds and seas will start increasing across the SE Gulf early this week. ...CARIBBEAN SEA... Please refer to the Special Features section above for potential heavy rainfall associated with a developing Central American Gyre (CAG) over the western Caribbean. A deep layer trough is producing widely scattered moderate to isolated strong convection over the central Caribbean. Recent scatterometer pass revealed near-gale to gale force winds within the strongest convection particularly east of Jamaica. Outside of convection, mainly moderate E to SE winds and seas of 3 to 4 ft are noted at the southeastern basin. While, mainly gentle E to SE winds and seas of 2 to 4 ft prevail across the remainder of the basin. For the forecast, moderate to locally fresh winds and moderate seas are expected across the E and central Caribbean today. A broad area of low pressure over the W Caribbean Sea and adjacent parts of Central America is supporting scattered to locally numerous showers and thunderstorms over the western Caribbean. Winds and seas may be locally higher in the showers and thunderstorms. Environmental conditions appear favorable for gradual development of this system during the next several days. A tropical depression is likely to form while the system moves slowly northward across the northwestern Caribbean Sea and Gulf of Mexico through the end of the week. There is a high chance of tropical cyclone formation in the next seven days. ...ATLANTIC OCEAN... A 1007 mb low pressure (AL96) centered near 28N56W is producing scattered moderate convection along with fresh winds and seas to 7 ft from 26N to 30N between 52W and 57W. Although the low remains embedded in a very dry environment, a short-lived tropical depression cannot be ruled out if showers and thunderstorms become better organized while the system moves generally northward at 5 to 10 kt over the central subtropical Atlantic. This system has a low chance of tropical formation through the next 48 hours. Farther E, the remnants of Tropical Storm Gordon are centered near 29N43.5W, with 1008 mb. This low is no longer producing convection, but a broad area of fresh SE to S winds and seas of 7 to 9 ft extend N of 26N between 37W and 43W. A weak surface trough stretches from N of 31N70W to 29N74W. Scattered moderate convection is noted 120 nm south of this trough axis, and moderate N winds along with 5 to 7 ft seas are noted N of 29N between 68W and 75W. For the remainder of the basin, weak high pressure is leading to light to gentle winds and seas of 3 to 5 ft, except from 19N to 28N west of 26W, where moderate to locally fresh NE winds and seas to 6 ft prevail. For the forecast W of 55W, an area of low pressure centered near 27N56W is producing scattered showers and thunderstorms. Although environmental conditions are not very favorable for development, a short-lived tropical depression cannot be ruled out if showers and thunderstorms become better organized while the system moves generally northward over the central subtropical Atlantic. There is a low chance of tropical formation over the next 48 hours. Otherwise, a weak cold front will move off the SE coast of the US this afternoon, then slowly move across the waters N of 25N through Mon night. $$ KRV