598 AXNT20 KNHC 301808 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1805 UTC Mon Sep 30 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 1600 UTC. ...SPECIAL FEATURES... Tropical Depression Joyce is centered near 22.4N 49.3W at 30/1500 UTC or 940 nm ENE of the Northern Leeward Islands, and drifting N at 2 kt. Estimated minimum central pressure is 1006 mb. Maximum sustained winds are 30 kt with gusts to 40 kt. Peak seas of 8 to 10 ft are occurring near and up to 100 nm north of the center. Scattered moderate convection is occurring northeast of the center from 23N to 26N between 43W and 48W, and well southeast from 18N to 21N between 42W and 44W. Joyce will continue to drift north for the next couple of days. A weakening trend will continue and Joyce should become a remnant low by this evening. Tropical Depression Twelve is upgraded into Tropical Storm Kirk, and centered near 13.5N 34.8W at 30/1500 UTC or 645 nm WSW of the Cabo Verde Islands. It is moving W at 10 kt with estimated minimum central pressure of 1001 mb. Maximum sustained winds are 30 kt with gusts to 40 kt. Peak seas of 12 to 14 ft are found just north of the center from 14N to 16N between 33W and 35W. Numerous moderate to scattered strong convection is noted from 11N to 15N between 32W and 37W. Kirk is moving toward the west, and a general westward to west-northwestward motion is expected to continue through Tuesday. A gradual turn to the northwest is forecast by Wednesday. Steady strengthening is forecast, and the Kirk will become a hurricane on Tuesday, and possible a major hurricane on Wednesday. Please read the latest High Seas and Offshore Waters Forecasts issued by the National Hurricane Center at website - https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml and https://www.nhc.noaa.gov/marine/offshores.php for more information. For the latest NHC Forecast/Advisory and Public Advisory on both Joyce and Kirk, please visit www.hurricanes.gov for more details. ...TROPICAL WAVES... An eastern Atlantic tropical wave is near the Cabo Verde Islands at 22W from 16N southward, and moving west around 15 kt. Scattered moderate convection can be found from 08N to 14N between 20W and 30W. Upper-level winds are expected to become more favorable for gradual development and a tropical depression could form on Wednesday. A western Caribbean tropical wave is near 83W from 20N southward across eastern Honduras and Nicaragua into Costa Rica. It is moving westward around 10 kt. Scattered moderate convection is present offshore of Nicaragua. Environmental conditions could become conducive for gradual development, and a tropical depression could form in a few days while the system is over the southern Gulf of Mexico or northwestern Caribbean Sea. Please see the latest Tropical Weather Outlook at website: https://www.nhc.noaa.gov/gtwo.php?basin=atlc&fdays=2 for more detail. ...MONSOON TROUGH/ITCZ... A monsoon trough enters the Atlantic along the Gambia coast, then curves northwestward to 12N27W, then continues west of Tropical Storm Kirk from 13N30W to 15N48W. Scattered moderate convection is flaring up south of the trough from 04N to 06N between the Sierra Leone/Liberia coast and 18W, and from 10N to 13N between 38W and 42W. The eastern end of the East Pacific monsoon trough is triggering scattered showers and isolated thunderstorms across the Caribbean waters near Costa Rica, Panama and northwestern Colombia. ...GULF OF MEXICO... A surface trough is persisting at the southwestern Gulf. Aided by divergent flow aloft, scattered moderate convection is occurring across the souther Gulf, including the Bay of Campeche. Gentle to locally moderate NE to SE winds and seas of 1 to 3 ft exist for the southern Gulf. Light to gentle winds and seas at 1 to 2 ft prevail for the northern Gulf. For the forecast, moderate to fresh northerly winds are expected near Veracruz through Tue night, then winds are forecast to increase to between fresh and strong Wed trough Fri night as a low pressure moves into the Gulf of Mexico during the latter portion of this week. Elsewhere, gentle to moderate winds and slight to moderate seas will prevail trough Fri. ...CARIBBEAN SEA... Convergent trades are coupling with divergent flow aloft to generate widely scattered moderate convection over the northwestern basin, including the Yucatan Channel. An upper-level low near 17N75W is inducing isolated thunderstorms at the central basin. Refer to the Tropical Waves and Monsoon Trough/ITCZ sections for additional convection. Moderate with locally fresh SE winds and seas of 3 to 5 ft are present across the northwestern and west-central basin. Light to gentle winds and 1 to 2 ft seas are noted near the ABC Islands, Costa Rica and Panama. Gentle E to SE winds and seas at 2 to 4 ft prevail elsewhere in the Caribbean Sea. For the forecast, environmental conditions appear to be conducive for gradual development, and a tropical depression could form around the middle part of this week while the tropical wave moves slowly west-northwestward. This system is then expected to move into the Gulf of Mexico during the latter portion of this week. Otherwise, gentle to moderate winds and slight to moderate seas will persist across the basin through Fri. ...ATLANTIC OCEAN... Please refer to the Special Features section on Tropical Depression Joyce and Tropical Storm Kirk. Refer to the Special Features, Tropical Waves and Monsoon Trough/ITCZ sections on convection in the Atlantic Basin. A 1016 mb high northeast of the Bahamas is sustaining light to gentle winds and seas of 3 to 6 ft in mixed moderate swells north of 20N between 55W and the Florida-Georgia coast. Outside the direct influence of Joyce, moderate to fresh with locally strong E to SE to S winds with 6 to 8 ft seas exist north of 20N between 35W and 55W. To the south from 10N to 20N between 40W and the Lesser Antilles, light to gentle winds and seas at 4 to 6 ft in mixed moderate swells are present. Farther east outside the influence from Kirk, moderate to fresh E to SE to SW winds and seas of 6 to 9 ft dominate from 10N to 20N between 35W and 40W. Gentle to moderate southerly and monsoonal westerly winds with 5 to 7 ft seas in mixed moderate swells prevail for the rest of the Atlantic Basin. For the forecast W of 55W, weak high pressure will dominate the western and central Atlantic. Under the influence of this high, mainly gentle to moderate winds and slight to moderate seas will prevail through mid week. NE swell to 8 ft will briefly impact the northeastern waters today. Newly upgraded Tropical Storm Kirk currently located over the eastern Atlantic could become a major hurricane by Wednesday. Seas generated by Kirk may reach the eastern forecast waters Thu night into Fri. $$ Chan