000 AXNT20 KNHC 251750 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1805 UTC Fri Aug 25 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 1200 UTC surface analysis and satellite imagery through 1730 UTC. ...SPECIAL FEATURES... TROPICAL STORM FRANKLIN: Tropical Storm Franklin is centered near 21.8N 67.8W at 25/1500 UTC or 190 nm E of Grand Turk Island, moving ESE at 4 kt. Estimated minimum central pressure is 1003 mb. Maximum sustained wind speed is 45 kt with gusts to 55 kt. Franklin remains a sheared tropical cyclone with numerous moderate isolated strong convection evident within within 420 nm in the Se quadrant. Peak seas are analyzed at 20 ft. Franklin is moving toward the east- southeast near 5 kt, and this motion will gradually become more easterly and northeasterly today. A sharp turn toward the north, with an increase in forward motion is expected tonight and Saturday, with a northward or north- northwestward motion over the western Atlantic continuing through early next week. Gradual strengthening is forecast by tomorrow, and Franklin will likely become a hurricane over the weekend. 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 NHC Forecast/Advisory and Public Advisory at www.hurricanes.gov for more details. NORTHWESTERN CARIBBEAN SEA AND EASTERN GULF OF MEXICO (AL93): Satellite images indicate that the area of low pressure over the northwestern Caribbean Sea is gradually becoming better organized, with increasing thunderstorm activity and a better-defined low- level circulation. Scattered moderate convection is from 18N to 23N between 82W and 86W, including the Yucatan Channel. Environmental conditions appear conducive for further development during the next several days, and a tropical depression is likely to form late this weekend or early next week while it moves generally northward over the eastern Gulf of Mexico. Interests in the Yucatan Peninsula of Mexico, western Cuba, and Florida should monitor the progress of this system. This disturbance has a MEDIUM chance of development through 48 hours. Please refer to the latest NHC Tropical Weather Outlook at www.hurricanes.gov for more details. ...TROPICAL WAVES... A new tropical wave is along 21W, from 22N southward, moving west at an uncertain 5-10 kt. Scattered moderate convection is from 10N to 15N east of 22W. Another new tropical wave is along 36W, from 02N to 11N, moving west at an uncertain 5-10 kt. Scattered moderate convection is from 05N to 11N between 33W and 41W. This wave has been added based upon a review of NHC tropical wave diagnostics, Hovmoller Charts, and this morning's visible satellite imagery showing a broad envelope of vorticity (spin) around the wave axis. A tropical wave is in the central Atlantic Ocean near 44W, from 13N to 25N, moving west at 10-15 kt. 1009 mb surface low pressure (AL92) is centered along the wave axis at 20N44W. Numerous moderate convection is from 18N to 22N between 43W and 46W. Recent scatterometer data shows gentle to moderate E winds across the axis. Seas are 6-7 ft. Environmental conditions could become more conducive for development this weekend, and a tropical depression could form by early next week while the system moves generally northwestward toward the central subtropical Atlantic. The chance of development through 48 hours is LOW. Please refer to the latest NHC Tropical Weather Outlook at www.hurricanes.gov for more details. ...MONSOON TROUGH/ITCZ... The monsoon trough enters the Atlantic Ocean near Dakar, Senegal, at 15N17W and continues to 08N43W. Convection is described in the tropical waves section. No ITCZ is analyzed. GULF OF MEXICO... A surface trough extends across the Bay of Campeche. Surface convergence across the central basin and an upper level low is producing scattered moderate convection, from 23N to 26N between 90W and 97W. Scattered moderate convection is also noted in the Yucatan Channel. Gentle to moderate easterly winds prevail, turning to the NE then the NW around the trough in the Bay of Campeche. Seas are 2-4 ft. For the forecast, weak high pressure centered across the SE U.S. will dominate the basin through the upcoming weekend, providing gentle to moderate winds. Looking ahead, a broad area of low pres over the NW Caribbean Sea is forecast to move generally northward over the NW Caribbean Sea and eastern Gulf of Mexico, and a tropical depression is likely to form late this weekend or early next week. Please refer to the latest NHC Tropical Weather Outlook at www.hurricanes.gov for more details. CARIBBEAN SEA... Please see the SPECIAL FEATURES section for information on AL93. Light to gentle trades prevail across the Caribbean amid a diffuse pressure gradient, with 2-4 ft seas. For the forecast, light to gentle winds, locally moderate in the south-central and SE Caribbean, and slight seas will prevail across the basin through the weekend. Looking ahead, an area of low pres in the NW Caribbean Sea on Sun is forecast to move generally northward over the NW Caribbean Sea and eastern Gulf of Mexico, and a tropical depression is likely to form late this weekend or early next week. Please refer to the latest NHC Tropical Weather Outlook at www.hurricanes.gov for more details. ATLANTIC OCEAN... Please refer to the Special Features section for information on Tropical Storm FRANKLIN. A stationary front enters the TAFB waters near 31N70W to 1010 mb low pressure near 27N74W. Gentle to moderate NE winds prevail north of the front with 6-7 ft seas. A surface trough extends southwest from the low pressure across the Bahamas. Showers and thunderstorms are near the Lesser Antilles. 1014 mb high pressure is centered near 26N56W. A weak surface trough is along 51W, from 20N to 28N. Scattered moderate convection ahead of a cold front in the eastern Atlantic is from 28N to 31N between 28W and 33W. The dominance of the subtropical Atlantic high pressure is interrupted by several midlatitude cyclones moving across the Atlantic north of the TAFB waters. As a result, the pressure gradient across the basin is rather diffuse, with light to gentle trades noted everywhere. Seas are 4-6 ft. For the forecast west of 55W, Tropical Storm Franklin will gradually turn NE later today and will move to 22.1N 67.1W this evening, 22.8N 66.9W Sat morning, 23.7N 67.5W Sat evening, strengthen to a hurricane near 25.2N 68.3W Sun morning, 26.8N 69.1W Sun evening, and 28.7N 69.4W Mon morning. Franklin will change little in intensity as it exits the TAFB waters early Tue. Moderate to fresh NE winds and seas to 7 ft will continue NW of the front through today. Winds may increase offshore Florida by Tue night due to a low pres system possibly moving through the eastern Gulf of Mexico. Please refer to the latest NHC Tropical Weather Outlook at www.hurricanes.gov for more details. $$ Mahoney