000 AXNT20 KNHC 231042 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1205 UTC Mon Oct 23 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 0600 UTC surface analysis and satellite imagery through 1000 UTC. ...SPECIAL FEATURES... Hurricane Tammy: Hurricane Tammy is centered near 21.4N 64.0W at 23/0900 UTC or 200 nm NNW of Anguilla, moving N at 9 kt. Estimated minimum central pressure is 993 mb. Maximum sustained wind speed is 70 kt with gusts to 85 kt. Hurricane-force winds extend out up to 20 nm of the center in the N semicircle, with tropical storm- force winds reaching up to 110 nm from the center in the E semicircle. Seas of 12 ft or greater extend out 180 nm from the center, especially in the N semicircle, where seas reach as high as 25 ft. Numerous strong convection is noted within 180 nm of the center, especially in the eastern semicircle. Please read the latest HIGH SEAS FORECAST, that is issued by the National Hurricane Center, at the website - https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml, and the latest Tammy NHC Forecast/Advisory and Public Advisory, at www.hurricanes.gov, for more details. SW Caribbean Low Pressure (Invest-AL95): A 1006 mb low pressure centered near 12N83W is producing numerous moderate to isolated strong convection within 210 nm of the center, especially in the NW semicircle. Fresh to strong winds are also occurring within about 90 nm of the center, especially to the east. The showers and thunderstorms continue to show signs of organization, and environmental conditions appear to be favorable for development. A short-lived tropical depression could form before the system moves inland over Nicaragua by early Tue. Regardless of development, this system could produce heavy rains over portions of Central America during the next couple of days. There is a medium chance of tropical formation within the next 48 hours. Please refer to the latest NHC Tropical Weather Outlook, at www.hurricanes.gov, for more details. ...MONSOON TROUGH/ITCZ... The monsoon trough axis extends from near the Senegal-Guinea- Bissau border to 08N32W. The ITCZ continues from 08N32W to 05N45W. Scattered moderate convection is noted along both of these features from 05N to 16N. ...GULF OF MEXICO... High pressure of 1018 mb centered near 26N89W is dominating the basin this morning. A weak cold front from the Florida Big Bend to the mouth of the Mississippi River is not producing any convection. Winds are light to gentle and anticyclonic in the central and eastern basin, with moderate to locally fresh winds in the western basin. Seas are less than 2 ft in the central and eastern Gulf, and 2 to 4 ft in the west. For the forecast, the weak cold front in the far NE Gulf of Mexico will slide E and dissipate today. High pressure will build southward in its wake. This will lead to increasing winds early this week, with fresh to locally strong E winds and building seas Mon night through Thu night. ...CARIBBEAN SEA... Please read the Special Features section above for details on low pressure in the far SW Caribbean that has the potential to become a tropical depression within the next 48 hours. A plume of moisture and low-level convergence associated with the outer impacts of Hurricane Tammy, centered a couple hundred nm N of the northern-most Leeward Islands, is inducing scattered moderate convection N of 16N and E of 63W. An area of diffluent flow aloft is leading to scattered moderate convection in the NW basin between Jamaica and 86W. Elsewhere, dry conditions generally prevail. Moderate to locally fresh winds are present in the NW basin, with light to gentle winds elsewhere. Seas are generally 2 to 4 ft. For the forecast, Hurricane Tammy will continue to move northward farther away from the area today. Showers and thunderstorms continue to show signs of organization in association with a low pressure system located over the southwestern Caribbean Sea. Environmental conditions appear to be favorable for development, and a short-lived tropical depression could form before the system moves inland over Nicaragua by early Tuesday. Regardless of development, this system could produce heavy rains over portions of Central America during the next couple of days. ...ATLANTIC OCEAN... Please read the Special Features section for details on Hurricane Tammy, centered about 200 nm N of Anguilla. A cold front has stalled from 31N61W to central Cuba. Scattered moderate convection is noted W of this boundary, N of 28N and E of 65W. Winds behind the front are generally moderate and N. To the E of this boundary and Hurricane Tammy, and N of the ITCZ and monsoon trough, there's a broad area of mainly moderate trades. A 1024 mb high pressure centered near 33N38W is dominating much of the eastern Atlantic, and gentle NE winds are prevalent to the E of 30W. A surface trough S of 16N along 56W is producing scattered moderate convection within 150 nm both sides of its axis. Seas of 5 to 7 ft dominate the basin, with lesser seas in the vicinity of and to the west of the Bahamas. An area of northerly swell is leading to seas of 8 to 10 ft E of 30W and N of the Cabo Verde Islands. For the forecast W of 55W, Hurricane Tammy will move to 22.2N 63.7W this afternoon, 23.2N 62.9W Tue morning, and 24.1N 61.7W Tue afternoon. Hurricane Tammy will 25.1N 60.5W Wed morning, 26.5N 59.3W Wed afternoon, and 28.0N 58.7W Thu morning. Tammy will become extratropical SE of Bermuda early Fri. Farther W, a stationary front from near 31N61W to central Cuba will remain in place this week and as in interacts with Hurricane Tammy, the gradient between it and high pressure building in from the United States will increase. This will lead to the development of a broad area of strong NE winds and rough seas across much of the area west of the boundary starting tonight and continuing through the week. $$ KONARIK