000 AXNT20 KNHC 130005 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0005 UTC Fri Sep 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 1800 UTC surface analysis and satellite imagery through 2345 UTC. ...SPECIAL FEATURES... Tropical Depression Seven is centered near 18.3N 35.9W at 12/2100 UTC or about 700 nm WNW of the Cabo Verde Islands, moving WNW at 14 kt. Estimated minimum central pressure is 1007 mb. Maximum sustained wind speed is 30 kt with gusts to 40 kt. Peak seas are around 10 or 11 ft. Satellite imagery shows that the depression has gotten more organized since last night. Scattered moderate convection observed is less in coverage than earlier today. The latest scattered moderate convection is noted within 120 nm of the center in the SE quadrant and within 60 nm elsewhere from the center. The convection appears fractured, with no solid convective banding features noted at the present time. The depression is forecast to undergo a west-northwest motion at a slower forward speed over the next few days. Some strengthening is forecast during the next 48 hours, and the depression could become a tropical storm tonight or on Fri. Please read the latest HIGH SEAS FORECAST issued by the National Hurricane Center at website - https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml and the latest Tropical Depression Seven NHC Forecast/Advisory and Public Advisory at www.hurricanes.gov for more details. ...TROPICAL WAVES... A central Caribbean tropical wave is near 73W extending from Haiti southward to inland northeastern Colombia. It is moving westward around 10 kt. Drier air at low to mid levels is hindering any significant convection. ...MONSOON TROUGH/ITCZ... The monsoon trough axis enters the Atlantic just south of the coastal border of Mauritian-Senegal and reaches westward to the Cabo Verde Islands. It then resumes northwestward from south of Tropical Depression Seven at 14N35W to 12N46W. Numerous moderate to strong convection is moving offshore the coast of Africa, and it is within 240 nm south of the trough between 15W and 20W. Scattered moderate convection is west-southwest of the monsoon trough from 10N to 14N between 25W and 29W. The eastern end of the East Pacific monsoon trough is triggering scattered moderate convection over the southwestern Caribbean south of 12N and west of Colombia to inland Costa Rica and Panama. ...GULF OF MEXICO... A surface trough extends from Post-Tropical Cyclone Francine that is presently located north of the area over northwestern Louisiana, south-southwestward to near 29N92W and to near 27N96W. No significant convection is noted. A warm front is inland the Florida panhandle. Convergent southerly winds near this front are coupling with tropical moisture resulting in lines of scattered showers and thunderstorms near and offshore from the Florida Big Bend area. This activity reaches southwestward to the central Gulf near 26N91W. Frequent lightning is being observed with this activity. Latest ASCAT satellite data passes show gentle to moderate south to southwest winds over the NE Gulf. Buoy and altimeter data indicate seas of 5 to 7 ft with these winds. Mainly gentle southerly winds and 2 to 4 ft seas are present across the southern west-central Gulf, including the Bay of Campeche. Gentle to moderate southwest to northwest winds with seas of 3 to 5 ft continue over the NW Gulf. For the forecast, high pressure will become established over the north-central Gulf this weekend, with rather tranquil conditions expected throughout the basin. ...CARIBBEAN SEA... A relatively fair and modest trade-wind pattern continues across much of the basin. An upper-level trough is generating scattered moderate convection at the eastern basin. Refer to the Monsoon Trough/ITCZ section for additional convection in the Caribbean Sea. Gentle to moderate northeast to east and to southeast trade winds along with seas of 2 to 4 ft are over the central and eastern sections of the basin, and the Gulf of Honduras. Gentle northeast to east and to southeast winds and relatively low seas of 1 to 3 ft remain over the rest of the basin. For the forecast, a tropical wave extending from Haiti to northern Colombia will move across the remainder basin through the next few days. Moderate to locally fresh winds will pulse at times offshore of eastern Honduras, while moderate to locally fresh winds pulse in the south-central Caribbean through the beginning of next week. Mainly gentle to moderate trades will prevail otherwise. Slight to moderate seas will prevail across the waters through the next several days. ...ATLANTIC OCEAN... Please see the Special Features section for details on Tropical Depression Seven in the far eastern Atlantic. A stationary front reaches westward from a 1014 mb low near 31N76W to inland northeastern Florida. Convergent southeasterly winds south of this front are coupling with an upper-level trough resulting in scattered showers and isolated thunderstorms north of about 27N between 56W and the Florida-George coast, including the northwest Bahamas. Similar conditions are also evident farther south from 20N to 25N between 59W and 65W. Refer to the Monsoon Trough/ITCZ section for additional convection in the Atlantic Basin. A trough...former AL92...extends from near 18N53W to 15N50W. Scattered moderate convection is within 60 nm of 17N54W. Low pressure of 1010 mb...AL94..is near 16N58W. Scattered showers and thunderstorms are within 60 nm northwest of the low.The proximity of dry air near the system is expected to limit additional development over the next couple of days. Environmental conditions are expected to become even less conducive over the weekend while the system moves slowly west- northwestward. Scattered moderate convection moving westward is south of AL94W and just east of the Windward Islands from 11N to 13N between 58W and 60W. A broad surface ridge extends southwestward from a 1032 mb Azores high pressure center through 31N39W and to the general area of the southeastern Bahamas. This feature is supporting gentle to moderate northeast to east and southeast to south winds along with seas of 4 to 6 ft north of 24N between 30W and the Florida/Georgia coast, except moderate to fresh southeast winds with 5 to 8 ft seas off northeastern Florida north of 29N. To the south from 15N to 24N between 30W and the Great Bahama Bank/Leeward Islands, moderate to locally fresh northeast to east and to southeast winds and 5 to 7 ft seas exist. Farther south from Equator to 15N between 30W and the Windward Islands, gentle to locally moderate southeasterly winds and seas of 5 to 7 ft in mixed moderate swell prevail. For the forecast west of 55W, the aforementioned stationary front will continue to support moderate to fresh northeast to east winds and seas up to 8 ft north of it and over the northeast Florida offshore waters. The front will retreat northward as a warm front, and stall along 31N through the end of the week. In a few days, a non-tropical area of low pressure could form along a residual frontal boundary a few hundred miles off the southeastern U.S. coastline this weekend. Thereafter, some subtropical or tropical development is possible during the early part of next week while the system drifts to the north or northwest. Regardless of development, increasing winds and building seas will impact the waters near 31N by the end of the weekend into early next week. Gentle to moderate winds and slight to moderate seas will prevail otherwise. $$ Aguirre