000 AXNT20 KNHC 102355 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0005 UTC Wed Oct 11 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 1800 UTC surface analysis and satellite imagery through 2345 UTC. ...SPECIAL FEATURES... Gulf of Mexico Gale-force Event (Invest-AL93): Low pressure of 1007 mb low pressure is located over the southwestern Gulf near 22N95W while the southwestern most point of a NE to SW oriented stationary front reaches about 160 nm to the east of the low pressure center. The low is part of broad area of low pressure, and its circulation remains elongated and not well- defined, Satellite imagery shows scattered moderate convection within 60 nm north and northeast of the low. This activity is lifting northward. A recent ASCAT data pass indicates gentle to moderate northeast to east winds near the convection, with embedded patches of fresh to strong winds. Seas with the fresh to strong winds are 4-6 ft. Buoy 42055 at 22N94W presently has combined seas of 5 ft. Additional development of the low is becoming unlikely before the system merges with a developing frontal boundary over the western Gulf of Mexico on Wed, however, strong to gale-force winds will accompany the low and frontal boundary across the northern Gulf late tonight through Wed night. Seas are expected to build to around 9 ft with the gale-force winds on Wed. Potentially heavy rainfall along the Gulf Coast by the latter part of this week can be expected. Please, read bulletins and forecasts from your local National Weather Service office, and high seas forecasts issued by the National Weather Service, for more information. Please, refer to the latest High Seas Forecast at www.hurricanes.gov/marine for details. The Eastern Tropical Atlantic (Invest-AL92): A tropical wave has its axis along 30W from 03N to 17N. A 1009 mb low pressure center is along the wave axis near 10N. Satellite imagery shows increasing numerous moderate to strong convection, in clustering fashion, west of this system from 09N to 14N between 30W-38W. Scattered moderate convection is within 120 nm east of the wave and low from 09N to 13N, and within 60 nm of 14N29W. The environmental conditions appear to be conducive for gradual development. It is likely for a tropical depression to form during the next couple of days while the system moves west- northwestward or northwestward across the eastern and central tropical Atlantic. This system has a high chance of formation into a tropical cyclone during the next 48 hours. Please see the latest Tropical Weather Outlook issued by the National Hurricane Center at www.hurricanes.gov for more information. ...TROPICAL WAVES... A far western Caribbean Sea tropical wave has its axis along 86W south of 19N, moving westward at 10-15 kt. Scattered moderate convection is within 120 nm east of the northern part of the wave from 17N to 19N. Isolated showers and thunderstorms are west of the tropical wave. ...MONSOON TROUGH/ITCZ... The monsoon trough axis passes through the coastal plains of Guinea-Bissau near 12N16W and continues westward to the Invest- 1009 mb low pressure center that is the subject of the Invest AL92 low pressure near 10N30W and to 08N41W, where latest scatterometer data indicates the it transitions to the ITCZ and continues to 10N51W and to 10N59W. Aside from convection associated to Invest-AL92, scattered moderate to isolated strong convection is seen from 06N to 09N between 18W-22W. within 10N59W. Scattered moderate convection is within 30 nm of the trough between 16W-18W. ...GULF OF MEXICO... Please read the Special Features section for details about the INVEST-AL93 1007 mb low pressure center located in the southwestern part of the Gulf. Relatively weak high pressure is analyzed over the area. A stationary front stretches from extreme South Florida to just north of the Yucatan Channel and to near 22N92W. Latest ASCAT data passes depict light to gentle easterly winds across the Gulf, with the exception of the southwestern Gulf where gentle to moderate east winds along with seas of 3-5 ft are near the Special Features Invest-AL93 low. Seas elsewhere are 2-4 ft, except for 4-6 ft seas in the western Gulf area from 22N to 26N west of 94W. Broken to overcast multilayer clouds with embedded patches of rain along with pockets of scattered showers and isolated thunderstorms are over just about the entire basin along and northwest of the stationary frontal boundary. For the forecast, a stationary front extends from the Straits of Florida to offshore of the NW Yucatan Peninsula. 1006 mb low pressure is located near 22N94W. The front and low pres will lift northward tonight through Wed, reaching along 29N. The low pressure is expected to strengthen along the front tonight over the NW Gulf, and move eastward across the N central and NE Gulf Wed through Wed evening, then inland across N Florida Wed night. Scattered to numerous strong thunderstorms and strong to gale force winds will accompany this low pressure system and frontal boundary across the northern Gulf late tonight through Wed night. ...CARIBBEAN SEA... Scattered showers and thunderstorms are concentrated are over some sections of the western and central part of the sea from about 12N to 21N between 76W-84W. Drier air present through all levels of the atmosphere east of 84W is inhibiting deep convection from developing. Latest ASCAT data passes indicate fresh southeast trade winds in the south- central section of the Caribbean and gentle to moderate trade winds elsewhere. Moderate seas are nearly everywhere from 80W eastward, accept for the waters that are about 210 nm to the north of Panama. Slight seas are in the remainder of the Caribbean Sea, including in the waters that are about 210 nm to the north of Panama. The eastern part of the E Pacific monsoon trough is along 09N/10N and west of 75W. Scattered showers and thunderstorms are inland Costa Rica and Panama. For the forecast, weak high pressure across the Atlantic near 23N61W extends a ridge westward to the southeastern Bahamas. It will shift slightly west- northwestward into Thu morning. Moderate to fresh east-southeast winds will prevail across the eastern and central Caribbean today then become easterly tonight through Thu, pulsing to strong near the coast of NW Venezuela and N Colombia this evening. Scattered thunderstorms will prevail across the NW basin through Wed near a tropical wave currently along 85W. Fresh SE to S winds will develop across the NW Caribbean Wed and become strong Wed night through Thu as low pressure moves eastward across the northern Gulf of Mexico. Winds in the Gulf of Honduras will remain fresh through Fri. ...ATLANTIC OCEAN... Please read the Special Features section for details about the Invest-AL92 low pressure and tropical wave. A stationary front extends from near 31N63W to the NW Bahamas and to extreme South Florida. A surface trough is to the southeast and south of the front from near 31N57W to 28N66W and to 26N75W. Broken to multilayer clouds with embedded pockets of scattered showers and thunderstorms are northwest of a line from 31N52W to 26N63W and to the central Bahamas and central Cuba. Another trough is analyzed from near 31N45W to 25N47W and to near 16N54W while a cold front extends from a 1008 mb low that is just north of the area near 32.5N43W to 3N48W and northwestward to 33N51W where it transitions to a stationary front. Scattered showers and thunderstorms moving eastward are noted north of 26N between 32W-52W. A 1016 mb high pressure center is near 23N63W. Generally, weak high pressure remains across the area outside the aforementioned features. Mostly moderate to some fresh north winds are within 500 nm to the west of the coast of Africa from 19N northward. Moderate winds are from 25N northward between 40W and 50W, with the 31N46W 21N50W surface trough. Moderate winds are within 560 nm to the north of the monsoon trough/ITCZ between the 29W/30W tropical wave and 40W. Moderate or weaker winds are in the remainder of the Atlantic Ocean. Mostly moderate to some rough seas are within 850 nm to the northwest Invest-AL92 low pressure center and tropical wave. Mostly moderate or lower seas are over the rest of the Atlantic Ocean. Weak high pressure across the central Atlantic near 23N61W extends a ridge westward to the SE Bahamas. A weak stationary front extending from 31N69W to just offshore the upper Florida Keys will gradually dissipate into Wed night, as high pressure builds W across the remainder of the Bahamas. Large NE swell will continue across the waters east of 65W today then gradually subside. Low pressure along a front is expected to move eastward across northern Florida Wed night, then continue eastward and emerge across the western Atlantic bringing strong to gale force winds east of northern and central Florida Thu night, then move east of 72W Thu night, and across the northeast waters Fri and Fri night. Thunderstorms with large and confused seas are expected to accompany this low pressure system. $$ Aguirre