000 AXNT20 KNHC 221202 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1205 UTC Sun Oct 22 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 1200 UTC. ...SPECIAL FEATURES... Hurricane Tammy is centered near 18.9N 62.5W at 22/1200 UTC or 50 nm NE of Anguilla, moving NNW at 9 kt. Estimated minimum central pressure is 992 mb. Maximum sustained wind speed is 75 kt with gusts to 90 kt. Hurricane-force winds extend outward up to 20 nm, mainly N of the center. Tropical storm-force winds extend out up to 120 nm in the eastern semicircle. Seas of 12 ft or greater extend out up to 180 nm, especially N of the center where peak seas are near 25 ft. Numerous strong convection is noted from 13N to 20N between 59W and 63W. Please, consult bulletins and forecasts from your local weather office. 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. Eastern Atlantic Storm Warning: The METEO-FRANCE forecast consists of storm-force winds for the marine areas AGADIR and MADEIRA. Please, refer to the website, https://wwmiws.wmo.int/index.php/affiche/2, for details. ...MONSOON TROUGH/ITCZ... The monsoon trough passes from the coastal plains of SW Senegal to 09N25W. The ITCZ continues from 09N25W to 06N35W to 06N46W. Scattered moderate convection extends along the ITCZ from 05N to 17N. Scattered moderate convection is noted within 180 nm of the monsoon trough axis. ...GULF OF MEXICO... High pressure of 1015 mb centered near 25N89W is dominating most of the basin. A weak cold front extends from just S of Tampa Bay to 27N87W. Most of the basin has light to gentle anticyclonic flow, but areas W of 94W are experiencing moderate southerly return flow. Seas are 2 ft or less, except 2 to 4 ft in the areas of moderate winds. For the forecast, a cold front will skirt the far NE Gulf tonight. High pressure will build toward the region from the north in the wake of these fronts, leading to increasing E winds. Fresh to locally strong winds are expected Mon through at mid-week. ...CARIBBEAN SEA... Please read the SPECIAL FEATURES section for details about Hurricane Tammy. A weak surface trough extends from Cuba southward to a 1008 mb low pressure centered near 11N82W. Scattered moderate to isolated strong convection associated with this low is impacting areas S of 15N and W of 80W. Environmental conditions appear generally favorable for some development of this low over the next day or two before it moves inland over Central America by Tue. Scattered moderate convection, loosely associated with the aforementioned trough, is also impacting waters from Cuba and Jamaica to Honduras, including in the vicinity of the Cayman Islands. Moderate mainly N winds are ongoing in the western Caribbean, with light to gentle winds in the central and eastern Caribbean areas that are not being impacted by Tammy. Seas are generally 2 to 4 ft. For the forecast, Hurricane Tammy is near 18.5N 62.3W at 5 AM EDT, and is moving north-northwest at 9 kt. Maximum sustained winds are 75 kt with gusts to 90 kt, and the minimum central pressure is 992 mb. Tammy will move to 19.5N 62.9W this afternoon, 20.8N 63.5W Mon morning, and 21.9N 63.5W Mon afternoon. Hurricane Tammy will reach 22.7N 63.1W Tue morning, 23.2N 62.5W Tue afternoon, and 23.8N 61.9W Wed morning. Tammy will change little in intensity as it moves farther N of the Leeward Islands early Thu. ...ATLANTIC OCEAN... Please read the SPECIAL FEATURES section for details about Hurricane Tammy as well as storm conditions in the far eastern Atlantic. A cold front extends from 31N70W to the central Florida Peninsula. Associated convection has diminished overnight. Winds behind the front, N of 28N, are moderate, otherwise light to gentle winds prevail W of 65W. Elsewhere, a surface trough extends from 31N61W to the Turks and Caicos Islands. This trough is inducing scattered moderate convection N of 22N between 59W and 68W. To the E of the trough, a corridor of moderate to fresh S winds, along with seas of 8 to 10 ft, extend E to 55W. In the tropical Atlantic, a surface trough extends from 16N48W SW to French Guiana, causing scattered moderate convection within 150 nm of its axis. Near the northern vertex of this trough, a prolonged period of fresh winds has induced some seas of 7 to 9 ft. In the east Atlantic, a cold front extends from the Moroccan coast to 22N25W to 31W42W. A pre-frontal trough resides to the S of this front, roughly along 18N. Neither feature is producing significant convection, but fresh N winds are occurring behind the front, becoming strong NE of the Canary Islands. Seas behind the front increase rapidly due to swell generated from storm conditions to the north. E of 35W, seas are 8 ft or greater N of 25N and greater than 12 ft E of 30N and N of 28W. Seas of up to 18 ft are occurring N of the Canary Islands. For the remainder of area S of 22N and waters between 35W and 55W, seas are 5 to 7 ft and winds are moderate or less. For the forecast, hurricane Tammy is near 18.5N 62.3W at 5 AM EDT, and is moving north-northwest at 9 kt. Maximum sustained winds are 75 kt with gusts to 90 kt, and the minimum central pressure is 992 mb. Tammy will move to 19.5N 62.9W this afternoon, 20.8N 63.5W Mon morning, and 21.9N 63.5W Mon afternoon. Hurricane Tammy will reach 22.7N 63.1W Tue morning, 23.2N 62.5W Tue afternoon, and 23.8N 61.9W Wed morning. Tammy will change little in intensity as it moves farther N of the Leeward Islands early Thu. Farther W, a slow moving cold front stretches from near Bermuda to the central Florida Peninsula. This front will slide east and gradually dissipate into tonight. A second cold front will move off Florida tonight, then move E across the northern portions of the waters early this week. 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 Tue through Wed night. $$ KONARIK/GR