566 AXNT20 KNHC 130607 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0605 UTC Wed Nov 13 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 0000 UTC surface analysis and satellite imagery through 0500 UTC. ...SPECIAL FEATURES... Central and Western Caribbean Sea Invest Area AL99: A tropical wave is near 76W from Jamaica southward across a 1008 mb low (AL99) to northern Colombia. This system is moving westward around 5 kt. Numerous heavy showers and isolated thunderstorms are occurring at the north-central Caribbean north of 13N. Scattered showers and isolated thunderstorms are noted near southeastern Cuba and the Windward Passage. A surge of tropical moisture associated with this system will cause heavy rains over western Haiti through Wednesday, and Jamaica through Thursday. Environmental conditions appear conducive for development, and this system is likely to become a tropical depression within the next couple of days. Afterward, further development is probable through this weekend as this system moves slowly westward across the western Caribbean Sea. By early next week, it could turn northwestward. There is a high chance for tropical development on this system for the next 7 days. Please refer to the latest NHC Tropical Weather Outlook at www.hurricanes.gov for more details. Excessive Rainfall Risk across Southern Central America: Moist convergent southwesterly flow related to the monsoon trough will continue to cause heavy rain across Costa Rica and Panama through Saturday. The highest rainfall amounts are expected across southwestern Costa Rica and western Panama. This information is provided by the Weather Prediction Center's International Desk meteorologists. Please refer to your country's national weather bureau for more details. ...TROPICAL WAVES... Please refer to the Special Features section about a tropical wave related to AL99 at the Central Caribbean Sea. ...MONSOON TROUGH/ITCZ... A monsoon trough enters the Atlantic near the coastal border of Guinea-Bissau and Guinea, then runs southwestward to 08N18W. An ITCZ continues westward from 08N18W across 06N35W to 08N49W. Scattered moderate convection is seen south of the trough from 03N to 08N between the Sierra Leone/Liberia coast and 18W. Similar convection is occurring up to 150 nm along either side of the ITCZ east of 40W. The eastern end of the East Pacific monsoon trough is triggering scattered showers and isolated thunderstorms at the southwestern Caribbean Sea. ...GULF OF MEXICO... An elongated 1007 mb low, remnants of Rafael near 26N90W is causing patchy showers at the north-central Gulf. Moderate with locally fresh NE to E to SE winds and seas at 3 to 5 ft are seen at the north- central and southeastern Gulf, including the Florida Straits. Gentle to moderate NNE to E winds and 1 to 3 ft seas prevail for the rest of the Gulf. For the forecast, the remnants of Rafael will meander over the central Gulf through tonight before moving to the northwestern Gulf and dissipating Wed. The pressure gradient between a strong ridge building over the eastern United States and the low will support the development of moderate to fresh E to SE winds over the eastern half of the Gulf tonight through Thu, increasing to strong at the northeastern Gulf and Florida Straits Wed and Wed night. Afterward, a cold front will sink into the northeastern Gulf Thu and exit the Gulf Thu night. Moderate NE to E winds and slight to moderate seas will dominate the Gulf through the weekend. ...CARIBBEAN SEA... Please read the Special Features section about Invest Area AL99 and heavy rainfall. A surface trough reaches northward from eastern Honduras across a 1007 mb low at the Gulf of Honduras to the tip of western Cuba. Scattered moderate convection is seen at the Gulf of Honduras and at the lee of Cuba, including the Cayman Islands. Convergent southeasterly winds are generating isolated thunderstorms south of the Dominican Republic and near the ABC Islands. Refer to the Monsoon Trough/ITCZ section for additional convection in the Caribbean Sea. For the forecast, regardless of development on AL99, strong to near gale- force winds, rough seas and heavy rains are expected over the northwestern basin and portions of the southwestern basin through early next week. Otherwise, gentle to moderate winds and slight to moderate seas will dominate the central and eastern Caribbean through the forecast period. ...ATLANTIC OCEAN... A stationary front curves southwestward from a 1010 mb low south of the Azores across 31N30W to 20N62W, then continue northwestward as a warm front to a 1011 mb low near 29N68W. Patchy showers and isolated thunderstorms are occurring up to 80 nm along either side of the stationary front east of 52W. Scattered moderate convection is present near the warm front north of 21N between 60W and 68W. Refer to the Monsoon Trough/ITCZ section for additional convection in the Atlantic Basin. Fresh with locally strong NE winds and seas of 6 to 9 ft are evident north of 28N between 65W and the Georgia/northern Florida coast. Farther east, fresh to strong S to SW winds and 6 to 8 ft seas are noted north of 27N between 52W and 65W. Gentle to moderate NE to SSE winds and seas at 4 to 7 ft are found from 20N to 27N/28N between 52W and the Bahamas. Gentle to moderate NE to SE winds with 7 to 9 ft seas in large NW swell dominate north of 20N between 30W and 52W. For the Tropical Atlantic from 09N to 20N between 30W and the Lesser Antilles, gentle to moderate ENE to ESE winds and seas of 6 to 8 ft in mixed moderate swells exist. For the rest of the Atlantic Basin west of 30W, gentle to moderate with locally fresh ENE to SE winds and seas at 4 to 6 ft prevail. For the forecast W of 55W, moderate to fresh winds behind and ahead of a cold front sinking southward into 29N will become fresh to strong later tonight. Rough seas will also build across the region as the front reaches from 31N59W to Hispaniola Wed morning and then exit the western subtropical Atlantic waters Thu night. A second cold front may move south of 31N east of northeastern Florida Thu night into Fri, affecting the offshore waters north of 27N with mainly moderate to fresh winds through the weekend. $$ Chan