000 AXNT20 KNHC 030543 TWDAT Tropical Weather Discussion...Updated NWS National Hurricane Center Miami FL 0605 UTC Sun Sep 03 2023 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 0000 UTC surface analysis and satellite imagery through 0550 UTC. ....SPECIAL FEATURES... Tropical Storm Gert is centered near 29.1N 53.4W at 03/0300 UTC or 620 nm ESE of Bermuda, moving NNE at 5 kt. Estimated minimum central pressure is 998 mb. Maximum sustained wind speed is 50 kt with gusts to 60 kt. Gert remains a resilient compact tropical storm in strong wind shear conditions and has even managed to strengthen a little more. Shear is keeping scattered moderate to strong convection within 60 nm to the southeast of the center. The tropical storm is moving north-northeastward at 5 kt. This motion with a gradual increase in forward speed is expected during the next day or so as the system getst swept up by the much larger circulation of Post-Tropical Cyclone Idalia. Seas are 12 ft or greater within 90 nm in the southeast quadrant of the storm. No significant change in strength is expected before Gert is forecast to generate into a trough of low pressure early Monday. 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 Gert NHC Forecast/Advisory and Public Advisory at www.hurricanes.gov for more details. Tropical Storm Katia is centered near 26.5N 31.0W at 03/0300 UTC or 740 nm NNW of the Cabo Verde Islands, moving NNW at 14 kt. Estimated minimum central pressure is 1002 mb. Maximum sustained wind speed is 40 kt with gusts to 50 kt. Katia has noticeably weakened since the previous advisory. Remnants of convection appear to be separating from the low-level circulation and no new bursts have formed in the past few hours. A turn to the northwest is expected shortly, and this general motion with a decrease in forward speed is expected through Monday. Environmental conditions are expected to become increasingly unfavorable, with strong-to-moderate vertical wind shear and dry mid-level humidities. Therefore, gradual weakening is expected, and the system could degenerate into a remnant low on Monday. Please read the latest HIGH SEAS FORECAST issued by Meteo- France at website https://wwmiws.wmo.int/index.php/metareas/affiche/2 and the latest Katia NHC Forecast/Advisory and Public Advisory at www.hurricanes.gov for more details. ...TROPICAL WAVES... A tropical wave (AL95) is near 23W from 18N southward, moving W at 10-15 kt. Scattered moderate convection is from 09N to 13N between 23W and 27W, south-southwest of the Cabo Verde Islands. Environmental conditions appear conducive for some gradual development of this system by the middle part of this week, and a tropical depression is likely to form while it moves westward to west-northwestward over the eastern and central portions of the tropical Atlantic. This tropical wave has a low chance of development through 48 hrs. A Caribbean tropical wave is near 67W, from 18N southward, moving west at 10-15 kt. Isolated moderate convection is depicted from 14N to 17N between 65W and 69W. A central Caribbean Sea tropical wave is along 78W from 20N southward, moving W at 10-15 kt. A few thunderstorms are active off Colombia near 11N76W. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from 09N14W to 05N22W to 07N31W. No significant convection is noted at this time. GULF OF MEXICO... Light to gentle E to SE winds across the northeast Gulf indicate a stalled frontal boundary over that region is rapidly dissipating, leaving a stalled frontal boundary along the northern Gulf coast from Apalachicola, Florida to Alabama. A few showers and thunderstorms are evident near a surface trough paralleling the Florida coast over the far southeast Gulf. Farther west, a broad surface trough is evident over the southwest Gulf. Moderate to fresh NE to E winds may be funneling along the north coast of the Yucatan peninsula behind the trough, but light to gentle winds persist elsewhere with 1 to 3 ft seas. Scattered moderate convection is moving off the west coast of the Yucatan peninsula following the trough. For the forecast, a weak surface trough with moderate winds over the central Gulf will drift westward through Sun as high pressure continues to build over the Gulf waters. Winds and seas could be higher near thunderstorms associated with the trough. Moderate to locally fresh winds will pulse at night off the NW Yucatan Peninsula through Tue night. A surface trough will move off the Florida Peninsula Mon evening and move towards the north- central basin through Tue evening along with moderate to locally fresh E winds. Otherwise, light to gentle variable winds are forecast from Wed evening through Thu night. CARIBBEAN SEA... Please refer to the TROPICAL WAVES section above for information about convection in the Caribbean Sea. In addition to convection related to tropical waves there is a pre-frontal trough moving southward and is located south of central Cuba. Therefore, scattered moderate convection is depicted in the western Caribbean Sea. Moderate to locally fresh trades are noted in the south-central Caribbean, off northwest Venezuela and northeast Colombia, with seas of 5 to 6 ft. Elsewhere, outside of convection, trades are gentle to moderate with seas of 3 to 5 ft. For the forecast, gentle to moderate winds with slight to moderate seas will prevail through Sun across the basin. Fresh winds will return in the central and eastern Caribbean by Mon and continue through Thu night. ATLANTIC OCEAN... Please read the SPECIAL FEATURES section for details about Tropical Storm Gert and Tropical Storm Katia and the TROPICAL WAVES section for details about AL95. A cold front associated with Post-Tropical Cyclone Idalia extends from 31N60W to the central Bahamas. No significant shower or thunderstorm activity is noted along or near this front. Over the tropical Atlantic, a surface trough extends from 14N37W to 07N49W. Outside of the winds and seas discussed in the SPECIAL FEATURES section associated with Tropical Storms Gert and Katia, mostly gentle to moderate winds and 4 to 6 ft combined seas are present across the Atlantic. For the forecast west of 55W, the low associated with Post- Tropical Cyclone Idalia continues to move farther north from the area. Strong winds around the low will diminish across the northern offshore waters by Sun night and into Mon morning. Rough to very rough seas will continue through the next few days and subside by Tue. Tranquil conditions can be expected through Thu. $$ KRV