000 AXNT20 KNHC 032209 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 2043 UTC Thu Sep 3 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 1800 UTC surface analysis and satellite imagery through 2200 UTC. ...SPECIAL FEATURES... Tropical Depression Nana is centered near 16.0N 91.1W at 03/2100 UTC or 190 nm WSW of Belize City moving WSW at 12 kt. Estimated minimum central pressure is 1006 mb. Maximum sustained wind speed is 30 kt with gusts to 40 kt. On the forecast track, the center of Nana will move over southeastern Mexico tonight, then move over the Gulf of Tehuantepec on Friday. Nana continues to weaken over land, with only a small area of convection remaining near and to the south of the low-level center. Continued weakening is expected, and Nana is likely to be a remnant low pressure area by the time it reaches the Gulf of Tehuantepec in 12-24 h. Nana will continue to produce heavy rainfall, with isolated maximum amounts as high as 3 to 6 inches over Guatemala and portions of southeastern Mexico. These rainfall amounts may produce life threatening flash floods and mudslides. Please consult products from your local weather office. Please read the latest NHC Public Advisory at https://www.nhc.noaa.gov/text/MIATCPAT1.shtml and Forecast/ Advisory at https://www.nhc.noaa.gov/text/MIATCMAT1.shtml for more details. Tropical Depression Omar is centered near 35.4N 60.1W at 03/2100 UTC or 300 nm NE of Bermuda moving ESE at 9 kt. Estimated minimum central pressure is 1005 mb. Maximum sustained wind speed is 30 kt with gusts to 40 kt. Omar remains a sheared depression with a deep convective mass decoupled well to the south of the surface circulation center. Gradual weakening is forecast, and Omar is expected to become a remnant low on Friday. The remnant low should dissipate on Saturday. 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. ...TROPICAL WAVES... A tropical wave axis is near 20W, from 18N southward. A 1007 mb low pressure is analyzed along the wave axis near 15N. This wave is merging with another disturbance located a couple of hundred miles south of the Cabo Verde Islands, resulting in an extensive area of disorganized showers and thunderstorms. Development of this system is likely to be slow during the next couple of days while it moves west- northwestward at about 15 mph. After that, a tropical depression is more likely to form early next week over the central tropical Atlantic where environmental conditions are forecast to be more favorable for development. The latest Tropical Weather Outlook states that this system has a high chance of tropical cyclone formation through 5 days. Refer to the latest Tropical Weather Outlook at www.hurricanes.gov for more details. A tropical wave axis is near 26/27W, from 18N southward, moving westward 10 to 15 knots. Associated convection is noted in the monsoon trough section below. A 1007 mb low pressure that developed along this wave has lingered behind the wave, centered near 11.5N24.5W. There is a low chance for this system to develop into a tropical cyclone within the next 48 hours, with a medium chance of development through the next five days. Refer to the latest Tropical Weather Outlook at www.hurricanes.gov for more details. A tropical wave axis is near 45W S of 18N, moving westward at 10 to 15 kt. No significant convection is noted with this wave. A tropical wave axis is near 58W from 19N southward, moving westward at 10 to 15 kt. Isolated showers are noted within 60 nm west of the wave axis from 13N to 16N. Moisture related to this wave will spread over the Lesser Antilles tonight into Fri, increasing the likelihood of showers and isolated tstms. A tropical wave axis is over the Caribbean Sea near 79W south of 18N, moving W 10 to 15 knots. Scattered moderate to isolated strong convection is observed from 12N-18N between 77W- 81W. ...MONSOON TROUGH/ITCZ... The monsoon trough passes extends from 17N16W to 12N27W to 12N43W. Scattered moderate isolated strong convection is noted from 06N to 15N between 17W and 30W. A large monsoon circulation prevails across the eastern Atlantic. As typical with a strong monsoon circulation, three low pressure systems are embedded within the monsoon trough. Two of them are mentioned in the Tropical Waves section above. The third one is near 12.5N36.5W, with scattered moderate convection within 90 nm NW quadrant of low center. GULF OF MEXICO... A ridge, extending from the Atlantic Ocean, dominates the Gulf waters. A 1018 mb high pressure is over the NE Gulf near 29N88W. Light to gentle winds prevail in the vicinity of the low. Moderate winds prevail over the SE Gulf. Gentle winds prevail elsewhere. The high pressure over the northeastern Gulf will dissipate through Fri ahead of a weak front moving into the northern Gulf Sat. The front will stall over the northern Gulf Sun, then slowly dissipate through early next week. Looking ahead, another stronger cold front may enter the northwest Gulf by the middle of next week. CARIBBEAN SEA... Abundant moisture prevails across the Caribbean, with satellite derived precipitable water values showing very high deep layer moisture over most of the basin. Clusters of showers and thunderstorms are observed in a large swath from the Lesser Antilles all the way to the NW Caribbean, including the Yucatan Channel. Moderate to fresh winds prevail across much of the Caribbean, except for the SW Caribbean where light to gentle winds prevail. Moderate to fresh trades will persist over the central Caribbean through Sun with gentle to moderate breezes elsewhere through early next week. ATLANTIC OCEAN... A surface ridge extends east to west across the waters north of 25N. This is supporting light and variables winds N of 25N, with gentle to moderate winds along the southern periphery of the ridge. Pulses of fresh to strong winds are possible north of Hispaniola and near the Windward Passage tonight. The ridge will dissipate by Sun ahead of a weak frontal boundary entering the area from the north, but otherwise little change is expected into early next week W of 65W. Farther east, fresh to locally strong SW winds and 8 to 9 ft seas are south of the monsoon trough, mainly east of 35W. As previously mentioned, the monsoon trough is very active over the eastern tropical Atlantic, and there is a high chance a tropical depression will form in the eastern or central tropical Atlantic by early next week. $$ AL