000 AXNT20 KNHC 222318 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0005 UTC Mon Sep 23 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 1800 UTC surface analysis and satellite imagery through 2300 UTC. ...SPECIAL FEATURES... Potential Heavy Rainfall in Central America: A Central American Gyre (CAG) is gradually developing over Central America with a broad 1007 mb low pressure analyzed near 15N83W. Scattered to numerous moderate to strong convection is evident across the western half of the Caribbean basin, mainly W of 70W. Environmental conditions appear favorable for development of this system, and a tropical depression or tropical storm is likely to form during the next few days while moving northward across the northwestern Caribbean Sea and Gulf of Mexico. Regardless of development, this disturbance is expected to produce heavy rains over portions of Central America during the next several days. Interests in the northwestern Caribbean, Yucatan Peninsula of Mexico, and western Cuba should closely monitor the progress of this feature. Later this week, the system is forecast to move generally northward across the Gulf of Mexico, and interests along the northern and northeastern Gulf Coast should also monitor the progress of this system. There is medium chance of development in the next 48 hours, while 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 tropical wave is analyzed along 18W from 06N to 18N. The wave is moving W at about 10 kt. Scattered moderate convection is depicted from 10N to 15N and E of 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. A tropical wave is analyzed along 43W from 04N to 17N. Scattered showers are noted from 11N to 16N between 45W and 47W. ...MONSOON TROUGH/ITCZ... A monsoon trough enters the Atlantic near 12N17W, then extends southwestward to 08N36W. The ITCZ continues from that point to 08N40W, then resumes W of a tropical wave near 10N48W to 11N57W. No significant convection is depicted 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 the basin at this time. Dry conditions prevail with light to gentle E winds and seas of 3 ft or less. For the forecast, disorganized showers and thunderstorms located over the western Caribbean Sea are associated with a very broad area of low pressure. 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. Regardless of development, winds and seas will start increasing across the SE Gulf early this week, and spread across the eastern Gulf thereafter. ...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 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, moderate E to SE winds and seas of 3 to 4 ft are noted at the southeastern basin. Gentle E to SE winds and seas of 2 to 4 ft prevail across the remainder of the basin. For the forecast, disorganized showers and thunderstorms located over the western Caribbean Sea are associated with a very broad area of low pressure. 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. Regardless of development, winds and seas will increase over the NW Caribbean early this week. ...ATLANTIC OCEAN... Refer to the section above for details on the tropical waves moving across the basin. A cold front enters the western Atlantic, analyzed from 31N68W to 28N76W. Scattered showers are noted along the front. To the east, a 1007 mb low pressure centered near 28N56W is producing scattered showers along with fresh winds and seas to 6 ft from 24N to 30N between 52W and 57W. Development of this system is not expected due to dry air and increasing upper-level winds during the next couple of days, while the low moves slowly northward. Farther E, another low is analyzed near 30N44W. This low is no longer producing convection, but a broad area of fresh SE to S winds and seas of 7 to 8 ft extend N of 26N between 36W and 44W. To the SE, A surface trough is analyzed from 17N36W to 12N30W. Scattered showers are noted along the trough. 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 18N to 26N and E of 26W, where moderate to fresh NE winds and seas to 6 ft prevail. For the forecast W of 55W, the west Atlantic weak cold front will move across the waters N of 25N through the middle of the week. Mainly light to gentle winds, occasionally moderate, will prevail. A set of northerly swell will propagate into the northern waters Mon, bringing an increase in seas over the waters N of 30N through the middle of the week. $$ ERA