000 AXNT20 KNHC 230605 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0605 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 0000 UTC surface analysis and satellite imagery through 0550 UTC. ...SPECIAL FEATURES... The center of Hurricane Tammy, at 23/0300 UTC, is near 20.8N 64.0W. TAMMY is moving toward the NW, or 325 degrees, 08 knots. The estimated minimum central pressure is 993 mb. The maximum sustained wind speeds are 75 knots with gusts to 90 knots. The radius of hurricane-force winds is: within 20 nm of the center in the NE quadrant; within 10 nm of the center in the SE quadrant; within 0 nm of the center in the SW quadrant; and within 20 nm of the center in the NW quadrant. The radius tropical-storm force winds is: within 90 nm of the center in the NE quadrant; within 100 nm of the center in the SE quadrant; within 30 nm of the center in the SW quadrant; and within 70 nm of the center in the NW quadrant. The sea heights that are 12 feet or greater are: wiATLthin 210 nm of the center in the NE quadrant; within 150 nm of the center in the SE quadrant; within 90 nm of the center in the SW quadrant; and within 180 nm of the center in the NW quadrant. The maximum sea heights are 27 feet. Precipitation: scattered to numerous strong is within 180 nm of the center in the NE semicircle, and within 220 nm of the center in the SE quadrant. Mostly moderate to some rough seas are elsewhere within 870 nm of the center in the SE quadrant, and elsewhere within 630 nm of the center in the N 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. ...INVEST-AL95 IN THE SOUTHWESTERN CORNER OF THE CARIBBEAN SEA... A 1007 mb low pressure center is near 12N82.5W, in the SW corner of the Caribbean Sea. Precipitation: widely scattered to scattered moderate, and isolated strong is within 225 nm of the center in the NW semicircle. Widely scattered moderate to isolated strong is from 17N to 20N between the Windward Passage and 83W. Isolated moderate is elsewhere from 16N southward from 77W westward. The precipitation is continuing to show signs of organization. The environmental conditions appear to be favorable for development. It is possible that a short-lived tropical depression may form before the system moves inland in Nicaragua by early Tuesday. It is possible that this system may produce heavy rains in parts of Central America during the next couple of days. The chance of formation into a tropical cyclone during the next 48 hours is medium. Please, refer to the latest NHC Tropical Weather Outlook, at www.hurricanes.gov, for more details. ...MONSOON TROUGH/ITCZ...ATL The monsoon trough passes through the coastal plains of SW Senegal, to 10N30W, and 08N32W. The ITCZ continues from 08N32W, to 05N40W, and 06N42W. Precipitation: widely scattered moderate to isolated strong is from 05N to 16N between 20W and 52W. Isolated moderate to locally strong is in the remainder of the area that is from 24N southward from 60W eastward. ...GULF OF MEXICO... Comparatively drier air in subsidence is apparent in water vapor imagery, from 16N to 23N between 84W in the NW part of the Caribbean Sea to 100W in Mexico. The dry air covers parts of the NW Caribbean Sea, the Yucatan Peninsula, and the areas of southern Mexico, including the Isthmus of Tehuantepec. A 1017 mb high pressure center is near 28N86W. Broad surface anticyclonic wind flow spans the Gulf of Mexico. A cold front is along 31N, from the Atlantic Ocean to Alabama. Slight seas are everywhere. Mostly moderate to some fresh winds are in the western half of the area. Moderate or slower wind speeds are in the eastern half of the area. A weak cold front over the far eastern Gulf has dissipated tonight. High pressure is building 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, for details about INVEST-AL95, that is in the SW corner of the area. Some of the precipitation that is surrounding Hurricane Tammy is reaching parts of the NE corner of the area. The monsoon trough is along 09N from 74W in Colombia, beyond Panama and Costa Rica, and into the Pacific Ocean. Precipitation: scattered to numerous strong is within 200 nm to the south of the monsoon trough between 81W and 86W. The 24-hour rainfall totals in inches, for the period that ended at 23/0000 UTC, according to the MIATPTPAN, are: 4.15 in Guadeloupe; and 0.16 in Curacao. Slight seas, and moderate or slower wind speeds, cover the Caribbean Sea. Hurricane Tammy is now a couple hundred miles north of Anguilla in the northernmost Leeward Islands, continuing to move farther away from the area. 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 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 about Hurricane Tammy. A cold front is along 31N60W, 23N70W, to the coast of Cuba near 22N77W. Precipitation: isolated moderate is to the northwest of the line that passes through 31N55W to the Windward Passage. Moderate to fresh W winds are from 29N northward between 65W and 75W. A cold front passes through the coastal plains of Mauritania near 21N17W, to 20N30W, to 25N44W. Precipitation: broken to overcast multilayered clouds, and possible rainshowers, are from 20N northward from 50W eastward. Moderate and fresh N-to-NE winds are from the cold front northward. Rough seas are from the cold front northward from 35W eastward. A surface trough is along 56W/57W, from 16N southward. Precipitation: widely scattered moderate to isolated strong is from 21N southward between 52W and 60W. Moderate and fresh easterly winds are from 10N to 27N between 34W and 60W. Fresh easterly winds are from 03N southward between 30W and 50W. Moderate or slower wind speeds, and moderate seas, are in the remainder of the Atlantic Ocean. A surface ridge extends from a 1025 mb high pressure center that is near 33N39W, to 28N60W. Hurricane Tammy is near 20.8N 64.0W at 11 PM EDT, and is moving northwest at 8 kt. Maximum sustained winds are 75 kt with gusts to 90 kt, and the minimum central pressure is 993 mb. Tammy will move to 21.5N 63.9W Mon morning, 22.5N 63.4W Mon evening, and 23.2N 62.6W Tue morning. Hurricane Tammy will reach near 24.0N 61.6W Tue evening, 25.3N 60.4W Wed morning, and 26.6N 59.5W Wed evening. Tammy will become extratropical SE of Bermuda late Thu. Farther west, a stationary front stretches from 31N61W to central Cuba. A cold front will move off Florida tonight, then dissipate as it moves eastward across the northern portions of the waters Mon. Looking ahead, high pressure building in the wake of the front combined with the impacts of Hurricane Tammy will bring an increase in winds and seas across the forecast area Mon night into Fri night. $$ mt/sk