000 AXNT20 KNHC 050609 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 205 AM EDT Wed Aug 05 2020 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 0000 UTC surface analysis and satellite imagery through 0520 UTC. ...SPECIAL FEATURES... The center of Post-Tropical Cyclone ISAIAS, at 05/0600 UTC, is near 46.1N 72.2W. This position also is about 60 nm/110 km to the SW of Quebec City, in Canada. ISAIAS is moving NNE, or 020 degrees, 33 knots. The estimated minimum central pressure is 1000 mb. The maximum sustained wind speeds are 40 knots with gusts to 50 knots. The maximum sustained wind speeds have decreased to near 40 knots, with higher gusts, mainly over water to the southeast of the center. Continued weakening is expected. The wind speeds are expected to slow down, to less than tropical storm-force, during the next few hours. The post-tropical cyclone is expected to dissipate in southeastern Canada, on Wednesday night or Thursday. Please read the latest NHC Public Advisory at https://www.nhc.noaa.gov/text/MIATCPAT4.shtml, and the Forecast/Advisory at https://www.nhc.noaa.gov/text/MIATCMAT4.shtml, for more details. ...TROPICAL WAVES... An Atlantic Ocean tropical wave is along 27W/28W, from 18N southward, moving W 10 to 15 knots. Precipitation: any nearby precipitation is in the monsoon trough. An Atlantic Ocean tropical wave is along 38W/39W, from 19N southward, moving westward 10 to 15 knots. Precipitation: any other nearby precipitation is in the monsoon trough/ITCZ. An Atlantic Ocean tropical wave is along 50W/51W, from 17N southward, moving westward 15 to 20 knots. Precipitation: any other nearby precipitation is in the ITCZ. A Caribbean Sea tropical wave is along 80W/81W, from 20N southward, moving W 15 knots. An upper level cyclonic circulation center is about 210 nm to the south of Jamaica. Upper level cyclonic wind flow covers the Caribbean Sea from 70W westward. Precipitation: widely scattered moderate to isolated strong covers the Caribbean Sea from 72W westward. ...MONSOON TROUGH/ITCZ... The monsoon trough passes the coastal sections of Mauritania near 18N16W, to 16N20W 10N30W, and 08N38W. The ITCZ is along 08N/09N between 40W and 50W, and from 08N52W to 11N62W. Precipitation: widely scattered moderate to isolated strong is within 360 nm to south of the monsoon trough and the ITCZ from 58W eastward. Isolated moderate to locally strong is elsewhere within 400 nm to the north of the monsoon trough and the ITCZ between 30W and 58W. GULF OF MEXICO... Upper level cyclonic wind flow covers the Gulf of Mexico, with a trough. The trough is supporting a stationary front that is inland, from northern Georgia to east Texas. Precipitation: isolated moderate to locally strong was covering the areas from SE Louisiana to east Texas, at 05/0000 UTC. That precipitation has been moving southeastward with time, and weakening and dissipating. Broken to overcast multilayered convective debris clouds cover the Gulf of Mexico from 27N northward between 87W and 95W. A 1015 mb high pressure center is near 28N93W. Broad surface anticyclonic wind flow spans the entire area. Light to gentle variable wind will dominate the Gulf of Mexico, N of 22N, through most of the period, as a weak surface ridge prevails. Moderate to fresh NE to E winds are expected at night in the eastern half of the Bay of Campeche, and along the Yucatan Peninsula, associated with a surface trough. CARIBBEAN SEA... An upper level cyclonic circulation center is about 210 nm to the south of Jamaica. Upper level cyclonic wind flow covers the Caribbean Sea from 70W westward. A tropical wave is along 80W/81W, from 19N southward. Precipitation: widely scattered moderate to isolated strong covers the Caribbean Sea from 72W westward. A second upper level cyclonic circulation center is between Dominica and Martinique. A separate area of upper level cyclonic wind flow covers the rest of the Caribbean Sea. Precipitation: isolated moderate is from 10N to 20N between 55W and 70W. Upper level NE wind flow is moving across the Atlantic Ocean, from 20N to 25N between 50W and 70W. Broken to overcast multilayered clouds and isolated moderate rainshowers are moving the northern sections of Puerto Rico and the Dominican Republic, from the Atlantic Ocean. The monsoon trough is along 08N/09N, from Colombia along 74W westward, beyond southern sections of Costa Rica. Precipitation: scattered to numerous moderate to strong is in Colombia and in the eastern Pacific Ocean coastal areas of Colombia from 03N to 09N between 75W and 78W, and from 09N to 10N between 72W and 74W near the border of Venezuela and Colombia. The Bermuda High across the W Atlantic Ocean, along with the eastward extension of the NE Pacific monsoon trough to Colombia, will support fresh to strong trade winds in the central basin through Wednesday, then extending to the SW Caribbean Sea on Wednesday night, and continuing through the weekend. Moderate to fresh winds are expected in the Gulf of Honduras, and in the eastern Caribbean Sea, during the same time period. ATLANTIC OCEAN... A surface trough passes through SE Georgia and NE Florida, into the Atlantic Ocean, to 28N74W, and to 28N68W. Precipitation: isolated moderate is from 28N northward from 77W westward. A 1016 mb low pressure center is near 32N50W. A dissipating stationary front extends from the low pressure center to 28N56W. A surface trough continues from 28N56W to 28N65W. Precipitation: isolated moderate is from 25N northward between 50W and 70W. A surface trough is along 38W/39W from 20N to 29N. The trough has been appearing in the scatterometer wind field for at least the last 18 hours or so. Precipitation: isolated moderate is within 120 nm to the east of the surface trough, and within 240 nm to the west of trough, from 20N to 30N. High pressure in the W Atlantic Ocean extends southwestward, to the NW waters, and it will persist into the weekend. This will promote moderate to locally fresh E-SE winds across the Great Bahama Bank and N of Hispaniola through the weekend. Strong winds are likely N of Hispaniola at night. A weak low pressure center will develop in the NE offshore waters tonight, and shift to the north central waters by Friday, before dissipating during the weekend. $$ mt