000 AXNT20 KNHC 260556 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0605 UTC Tue Sep 26 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 0500 UTC. ...SPECIAL FEATURES... Tropical Storm Philippe is centered near 17.6N 47.8W at 26/0300 UTC, about 875 nm E of the Northern Leeward Islands, and moving WNW at 10 kt. Maximum sustained winds are 45 kt with gusts to 55 kt. Estimated minimum central pressure is 1001 mb. Peak seas are 18 to 20 ft near and just northeast of the center. Westerly upper-level wind shear continues to displace the associate deep convection to the east of the center this evening. Scattered moderate to isolated strong convection is seen from 15N to 20N between 42W and 46W. Philippe will continue on the current motion and gradually weaken for the next few days. Please read the latest HIGH SEAS FORECAST issued by the National Hurricane Center, at the website https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml. The latest NHC Forecast/Advisory and Public Advisory can be read at www.hurricanes.gov, for more details. Invest Area (AL91): An eastern Atlantic tropical wave is near 34W from 17N southward through a 1010 mb low at 10N34W, and moving west around 15 kt. Numerous moderate to scattered strong convection is noted from 06N to 10N between 30W and 35W. Scattered moderate to isolated strong convection is found near the low from 10N to 15N between 33W and 40W. Moderate to fresh with locally strong ESE to SSE winds and 6 to 8 ft seas exist east of the wave axis from 05N to 12N between 29W and 32W. Environmental conditions are forecast to be conducive for gradual development, and a tropical depression is likely to form within the next few days as the system moves west- northwestward across the central tropical Atlantic. There is a medium chance of formation through 48 hours. ...TROPICAL WAVES... A central Caribbean tropical wave is near 80W from near the Cayman Islands southward across Panama into the East Pacific. It is moving westward around 15 kt. Scattered moderate to strong convection is present from 12N to 18N between 78W and 82W. Fresh to strong E to SE winds and 7 to 10 ft seas are found east of the Honduras/Costa Rica border from 14N to 18N between 77W and 83W. ...MONSOON TROUGH/ITCZ... A monsoon trough enters the Atlantic along the Guinea-Bissau coast near Bissau, then reaches southwestward to near 08N19W. It then continues from the aforementioned AL91 to 08N41W, and from 15N49W to 10N54W. An ITCZ extends westward from 08N19W to 07N27W. Widely scattered moderate convection is seen up to 100 nm north and 120 nm south of the first and second monsoon trough, and also the ITCZ. The eastern end of the East Pacific monsoon trough is causing isolated thunderstorms over the Caribbean waters near Panama. ...GULF OF MEXICO... A broad surface trough extends southward from the Florida Panhandle to the Yucatan peninsula. Widely scattered showers and isolated thunderstorms are occurring across the eastern Gulf. An outflow boundary is creating scattered showers and isolated thunderstorms along the Texas coastline. Gentle to moderate SE winds and seas of 2 to 3 ft are noted across the eastern Gulf, while gentle NE to E winds with 1 to 2 ft seas prevail for the rest of the Gulf. For the forecast, the broad surface trough will drift slowly into the western Gulf through midweek and dissipate. Meanwhile, weak high pressure will persist over the north-central and northeastern Gulf. This pattern will support gentle to moderate NE to E winds and slight seas across the region through the middle of the week. Winds may increase over the northern Gulf from the end of the week into the weekend as a cold front dips into the Gulf. ...CARIBBEAN SEA... A modest Bermuda High northeast of the Bahamas is maintaining a trade-wind pattern across much of the basin. Convergent trades are producing widely scattered showers and isolated thunderstorms near and south of Hispaniola. At the northwestern basin, scattered showers and thunderstorms are evident, including the Yucatan Channel and Gulf of Honduras. Refer to the Monsoon Trough/ITCZ and Tropical Waves sections for additional weather in the Caribbean Basin. Moderate to fresh easterly winds and seas of 5 to 7 ft dominate the central basin. Gentle to moderate ENE to E winds and 3 to 5 ft seas are present at the eastern basin. Light to gentle monsoonal winds and 2 to 4 ft seas exist just north of Costa Rica and Panama. Other than the area mentioned near the tropical wave, gentle to moderate E to SE winds and seas at 3 to 5 ft prevail elsewhere in the basin. In the forecast, the Bermuda High will support moderate to fresh trade winds across most of the eastern and central Caribbean into midweek, while fresh to strong pulses off northwest Venezuela and northeast Colombia during mainly the overnight and early morning hours. Seas will build in mixed NE and E swells across the waters east of the Leeward Islands starting late Tue, ahead of Tropical Storm Philippe. Philippe is expected to turn NW before reaching 55W, and move into the central Atlantic. ...ATLANTIC OCEAN... Refer to the SPECIAL FEATURES section at the beginning for details on Tropical Storm Philippe and Invest AL91. Convergent easterly winds south of the Bermuda High near 31N73W are generating scattered showers and isolated thunderstorms over the northwest and central Bahamas. A surface trough south of Bermuda is inducing widely scattered moderate convection within 100 nm of 26N63W. Refer to the Monsoon Trough/ITCZ and Tropical Waves sections for additional weather in the Atlantic Basin. The Atlantic Ridge associated with both the Bermuda and Azores Highs are promoting light to gentle winds and 4 to 7 ft seas in mixed moderate N and E swells exist north of 25N between 25W and the Georgia-Florida coast. From 20N to 25N, gentle to moderate with locally fresh ENE to ESE winds and seas of 5 to 8 ft are seen between 52W and 70W, and between 25W and 43W. Moderate to locally fresh E to ESE winds and seas of 2 to 5 ft are noted across the Bahamas and Great Bahama Bank. Moderate to fresh with locally strong easterly winds and 8 to 10 ft seas are evident from 20N to 25N between 43W and 52W. Gentle to moderate with locally fresh NNE to NE trades and seas of 4 to 7 ft dominate north of 18N between the northwest Africa coast and 25W, including the Canary Islands. Near the Cabo Verde Islands, moderate to fresh NE to E winds and seas fo 6 to 8 ft are noted from 12N to 18N between the central Africa coast and 43W. Outside the direct impact from Tropical Storm Philippe, gentle to moderate NE to E gentle to moderate winds and 5 to 7 ft seas in mixed moderate swells are present from 10N to 20N between 43W and the Lesser Antilles. Light to gentle with locally moderate monsoonal and southerly winds and seas of 5 to 7 ft in moderate southerly swell prevail for the remainder of the Atlantic Basin. For the forecast west of 35W, Tropical Storm Philippe will move to near 17.7N 48.5W Tue morning, 18.4N 50.4W Tue afternoon, and 19.3N 52.3W Wed morning. Then it is anticipated to track near 20.4N 54.0W Wed afternoon, 21.6N 55.4W Thu morning, and 22.2N 56.3W Thu afternoon. Philippe will change little in intensity as it moves to near 22.9N 57.7W Fri afternoon. Regardless of the exact position of the center later in the week, rough seas ahead of the storm can be expected east of 60W starting late Tue. Elsewhere, seas may build by Thu north of the Bahamas and east of Florida in NE swell. $$ Forecaster Chan