000 AXNT20 KNHC 022334 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0005 UTC Sat Sep 03 2022 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 2330 UTC. ...SPECIAL FEATURES... Hurricane Danielle is centered near 37.9N 43.5W at 02/2100 UTC or 780 nm W of the Azores stationary. Estimated minimum central pressure is 992 mb. Maximum sustained wind speed is 65 kt with gusts to 80 kt. Danielle has degraded some this afternoon with respect to its satellite presentation. Drier mid- level air appears to have wrapped into the circulation, and the cyclone now has more of a banded structure around the western and southern portions of the system. Scattered moderate convection is within 60 nm of the center, except 30 nm in the N semicircle. In its outer eastern periphery, similar convection is seen from 36N to 31N between 38W-41W. Danielle is forecast to meander over the open Atlantic during the next couple of days, then slowly turn toward the northeast early next week. Some additional strengthening is forecast during the next couple of days. Please read the latest NHC Public Advisory at https://www.nhc.noaa.gov/text/MIATCPAT5.shtml and Forecast/Advisory at https://www.nhc.noaa.gov/text/MIATCMAT5.shtml for more details. East of the Leeward Islands: A tropical wave has its axis along 58W, with low pressure of 1008 mb analyzed along it near 18N58W. The circulation associated with the low pressure has become better defined today and surface pressures have fallen a bit according to data from an Air Force Reserve Hurricane Hunter Aircraft. Convection of the numerous moderate to isolated strong type is increasing within 180 nm SE of the low and 90 nm NE of the low. Scattered moderate convection has recently developed within 60 nm of 20N57W. If the observed convection associated with the low persist through the evening, the system could become a tropical depression as early as tonight. The disturbance is expected to move slowly west-northwestward, toward the adjacent waters of the northern Leeward Islands. Regardless of development, locally heavy rains may occur over portions of the Leeward Islands during the next couple of days, and interests in that area should monitor the progress of the system. This system presently has a high chance of tropical cyclone formation during the next 48 hours. Please read the latest Tropical Weather Outlook issued by the National Hurricane Center at www.hurricanes.gov and the latest High Seas Forecast issued by the National Hurricane Center at https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml for additional information. ...TROPICAL WAVES... A far eastern Atlantic tropical wave has its axis along 28W, with low pressure of 1009 mb near 19N. It is moving westward at 10-15 kt. This system is surrounded by dry environmental air, and no deep convection is presently occurring with it. Possible isolated showers are noted to its northwest from 20N to 25N between 28W-31W. Significant development is not expected as this system moves generally west-northwestward into an area of unfavorable environmental conditions. ...MONSOON TROUGH/ITCZ... The monsoon trough axis extends from the coast of Mauritania at 17N16W to 16N23W. It resumes the southwest of the Special Features tropical wave near 12N30W to 09N43W, where it transitions to the ITCZ to 11N53W. Scattered moderate convection is noted from 06N to 10N between 45W-53W. GULF OF MEXICO... Weak high pressure remains present over the Gulf of Mexico supporting gentle to moderate return flow with seas in the 1-3 ft range, except near and to the W of the Yucatan peninsula where a thermal trough enhances the winds to moderate to fresh speeds with seas of 4-6 ft. Scattered showers and thunderstorms are noted over the northern Gulf, more concentrated over the NE part. Upper level divergence supports the latter convective activity. For the forecast, the weak high pressure will dominate the weather pattern across the Gulf waters through early next week maintaining gentle to locally moderate winds and slight to moderate seas. Moderate winds will pulse to fresh nightly over portions of the SW Gulf through Sat night due to the diurnal trough developing each afternoon over the Yucatan peninsula. CARIBBEAN SEA... An upper-level low is identified to be located just south of central Cuba. Scattered showers and thunderstorms are along and just inland eastern Cuba and over some sections of Jamaica. Similar shower activity is being enhanced by the eastern part of East Pacific monsoon trough in the SW Caribbean. Isolated showers and thunderstorms are elsewhere over most of the western and central Caribbean waters. An area of scattered showers and thunderstorms is affecting the Leeward Islands. This convective activity is ahead of the above mentioned low pressure that is presently located near 18N58W. Locally heavy rains may occur over portions of the Leeward Islands during the next couple of days, and interests in that area should monitor the progress of the system. Please, see the Special Features section for more details. Gentle to moderate trade winds are across the basin, with the exception of moderate to locally fresh winds in the lee of Cuba, Gulf of Honduras and just south of Hispaniola per latest ASCAT data passes. For the forecast, high pressure across the eastern seaboard of the U.S. will support moderate to fresh trades across the central and NW basin through Sat. Afterward, gentle to moderate trade winds will dominate through Wed. Broad low pressure located east of the Leeward Islands, associated with a tropical wave, will move slowly WNW over the next several days and yield generally light to moderate winds across the eastern Caribbean. Active weather associated with this feature is expected to impact the northeastern Caribbean through Mon. ATLANTIC OCEAN... Please, see the Special Features section for more information on an area of low pressure, located a couple of hundred miles east of the Leeward Islands, that presently has a high chance of tropical cyclone formation. An area of fresh to strong winds per scatterometer data between this area of low pressure and a high pressure to the NE covering the waters from 17N to 22N between 54W and 59W. Two tropical waves are between the W coast of Africa and the Lesser Antilles. Please, see the tropical waves section. A ridge dominates the remainder of the Atlantic forecast waters with a couple of 1021 mb highs located near 33N38W, and near 33N51W. These highs are located south of Hurricane Danielle. A surface trough extends from a 1016 mb low that is north of the area near 35N63W, south-southwest to 30N67W and westward to near 31N76W. For the forecast west of 55W, as previously mentioned, a broad low pressure of 1008 mb is centered east of the Leeward Islands near 18N58W. It will move west-northwest across the Atlantic waters adjacent to the northern Leeward Islands through Sat night. The system could become a tropical depression as early as tonight. Associated active squalls and thunderstorms will impact the Atlantic waters adjacent to the northern Leeward Islands through Sun. Elsewhere, weak high pressure is centered over the central Atlantic along 33N and extends west-southwest to near 70W. This pattern is expected to produce gentle to moderate winds across much of the remainder of the area through early next week. $$ Aguirre