000 AXNT20 KNHC 092353 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 753 PM EDT Mon Sep 9 2019 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 32N. The following information is based on satellite imagery, weather observations, radar and meteorological analysis. Based on 1800 UTC surface analysis and satellite imagery through 2320 UTC. ...SPECIAL FEATURES... The center of Tropical Storm Gabrielle, at 09/2100 UTC, is near 40.7N 45.4W, moving NE at 20 knots. It is located about 860 nautical miles WNW of the Azores. The estimated minimum central pressure is 1000 mb. The maximum sustained wind speeds are 45 knots with gusts to 55 knots. Scattered moderate convection is seen from 40N-46N between 42W-48W. Gabrielle will continue to move NE with an increase in forward speed is forecast over the next couple of days. Little change in strength is expected tonight, but a weakening trend is likely to begin Tuesday. Gabrielle is expected to become an extratropical low by Tuesday night and dissipate over the far North Atlantic Thursday. Please read the latest NHC forecast/ advisory under AWIPS/WMO headers MIATCMAT3/WTNT23 KNHC, or the website hurricanes.gov, for more details. ...TROPICAL WAVES... An Atlantic Ocean tropical wave is along 19W S of 19N, moving W at 10 knots. Scattered moderate convection is noted from 05N-18N between 18W-21W. An Atlantic Ocean tropical wave is along 46W S of 20N, moving W at 15 knots. A 1012 mb low is located along the wave near 14N46W. This system continues to produce disorganized showers and thunderstorms. Some slow development of this system is possible during the next two or three days before upper-level winds become unfavorable for tropical cyclone formation. It is expected to move generally westward across the tropical Atlantic Ocean for the next several days. This system has a 20 percent chance of formation through the next 48 hours. An Atlantic Ocean tropical wave is along 60W S of 17N, moving W at 15 knots. Scattered showers are noted in the vicinity of the wave axis. A Caribbean Sea tropical wave is along 81W S of 18N, moving W at 10 knots. Scattered showers and thunderstorms are noted within 50 nm of the wave axis from 10N-19N. A Caribbean Sea tropical wave is along 87W S of 21N, moving W at 10 knots. Scattered moderate to strong convection is noted near the wave, especially in Honduras and Nicaragua. Scattered moderate to strong convection is also occurring in the northern portion of the wave axis in the Yucatan. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through the coast of Senegal near 14N17W to 12N35W to 14N45W. The ITCZ begins near 12N48W to 10N59W. Aside from the convection associated to the tropical waves, scattered moderate convection is present around 200 nm south of the monsoon trough from 08N-15N between 25W-45W. Another area of scattered moderate convection is noted along the ITCZ from 07N- 12N between 48W- 55W. GULF OF MEXICO... An upper and mid level cyclonic circulation center is meandering into Texas. However, scattered moderate convection can be seen from 22N-26N between 91W-96W. A trough extends along this convection from 18N95W to 24N90W. Another trough is analyzed from 28N94W to 29N91W. An area of numerous strong convection is moving off the Yucatan into the Bay of Campeche from 20N-22N and E of 91W. Latest scatterometer data depicts light to gentle winds across the basin. High pressure ridging will prevail just N of the basin through the week. The ridging will maintain gentle to moderate easterly flow, except pulsing to fresh NW of the Yucatan Peninsula each evening. CARIBBEAN SEA... Refer to the section above for details on the tropical waves moving across the basin. Scattered moderate convection continues over the Greater Antilles from the Mona Passage to the Dominican Republic and across southern Cuba. Some of this activity is moving into adjacent waters. Numerous strong convection is occurring over Colombia due to the eastern Pacific monsoon trough, with some of these storms also moving into adjacent waters. Isolated thunderstorms are also seen across the Lesser Antilles. The upper level ridge will continue to suppress any deep convection across the eastern portion of the basin. Latest scatterometer data depicts moderate trades in the south- central Caribbean with light to gentle trades elsewhere. High pressure ridging will prevail N-NE of the basin through the week. The ridging will maintain moderate trades, except pulsing to fresh to strong in the S central Caribbean. A strong tropical wave may approach the tropical N Atlantic by the end of the upcoming weekend with gusty winds and squalls. ATLANTIC OCEAN... Refer to the section above for details on the tropical waves moving across the basin. An upper level trough is moving over the western Atlantic and extending into the Caribbean near the Windward Passage. A surface trough is noted from 20N70W to 24N66W. Scattered moderate convection is seen from 20N-26N between 65W-74W. Little-to-no development of this system is expected during the next day or two while it moves west-northwestward near the southeastern Bahamas. Environmental conditions could become a little more conducive for development when the disturbance moves near the northwestern Bahamas, south Florida and over the southeastern Gulf of Mexico late this week. A another surface trough extends south from T.S. Gabrielle, entering the forecast waters near 31N54W and extends westward to 29N65W. Scattered showers and thunderstorms are within 70 nm of this feature. An upper level low over the central Atlantic is producing scattered showers and thunderstorms from 21N-26N between 51W-56W. A 1021 mb high is analyzed near 27N53W and is ridging across the eastern Atlantic. The trough NW-N of Puerto Rico will track WNW across the area during the week reaching Florida late in the week. It will be accompanied by scattered to numerous showers and thunderstorms. Otherwise, relatively weak high pressure across the area will gradually lift northward through the week. $$ AKR