000 AXNT20 KNHC 272329 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0005 UTC Mon Jun 28 2021 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 2300 UTC. ...SPECIAL FEATURES... Satellite imagery and nearby buoy and ship observations indicate that a small low pressure system has formed about 435 NM east- southeast of the Georgia-South Carolina border. Surface pressures have begun to fall across the area, and showers and thunderstorms have recently become better organized. Some additional development of this system will be possible later today, and especially on Monday when the system will move across the warmer waters of the Gulf Stream, and a tropical depression could form before the system makes landfall along the southern U.S. coast. The low is expected to move westward today, and then west-northwestward at about 13 kt on Monday, reaching the coast of the southeastern United States by late Monday. Current forecasts indicate peak winds of 30 kt and seas of 11 ft in TAFB's waters. Latest Tropical Weather Outlook gives this system a medium chance of tropical cyclone formation through 48 hours. Please, read the latest Tropical Weather Outlook at www.hurricanes.gov, for more information. ...TROPICAL WAVES... A tropical wave axis is near 18W from 15N southward. This wave is identifiable from satellite imagery, tropical wave diagnostics, and the Hovmoler diagram. Scattered moderate convection is noted from 00N-11N between 18W-27W. A second tropical wave is along 34W, from 17N southward. A 1009 mb low pressure center is analyzed along the tropical wave, near 10N. Scattered moderate convection is within about 180 nm NW quadrant of the center. Little, if any, development of this system is expected for the next couple of days, followed by some gradual development by Wednesday and continuing through the end of the week while it moves it moves westward to west-northwestward at 15-20 kt. Please, read the latest Tropical Weather Outlook at www.hurricanes.gov, for more information. Another tropical wave is along 58W, from 18N southward, moving W at 10 to 15 knots. Convection is limited near the wave axis that is surrounding by African dust. A tropical wave is moving westward across the Caribbean Sea and extends from Hispaniola to western Venezuela. It axis is near 73W moving W at 10 kt. The wave is helping to induce some convective activity over Hispaniola. A tropical wave has reached the Yucatan Peninsula and northwestern Central America. It axis is along 90W. Scattered showers and thunderstorms are flaring up near the northern end of the wave axis over the Yucatan Peninsula. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through the coastal plains of Guinea near 10N16W to a 1009 mb low pressure located near 10N34W to 08N42W. The ITCZ axis continues from 08N42W to 10N57W. Convection that is occurring is primarily associated with tropical waves, as described above. GULF OF MEXICO... An upper-level low is still spinning over the NW Gulf supporting scattered to numerous showers and thunderstorms north of 25N and west of 88W. A surface trough induced by this upper this low, extends 29N93W to 26N97W. Surface winds - aside from those enhanced locally by thunderstorms - are generally E to SE gentle to moderate winds. Seas are 4-6 ft over the central Gulf and 2-4 ft over the W and E Gulf. In the forecast, the trough over the northwest Gulf will move inland over Texas through late today, bringing scattered showers and thunderstorms as well as fresh SE winds along with it. Otherwise, gentle to moderate SE winds will persist through the latter part of the week between a trough over the far southwest Gulf and high pressure over the western Atlantic. CARIBBEAN SEA... A weak north-south pressure gradient is forcing only moderate to fresh E trades across the Caribbean today. Seas are 4-6 ft in the central and E Caribbean and 2-4 ft in the W Caribbean. The east Pacific monsoon trough is associated with scattered moderate and isolated strong convection south of 13N west of 78W. The tropical wave currently south of Haiti will move westward across the basin through Mon. Winds and seas will increase across mainly the southeast and south central Caribbean as high pressure builds over the basin following the tropical wave. Winds and seas will also increase in the Gulf of Honduras starting Mon night following the tropical wave. Another tropical wave may approach the Lesser Antilles late in the week. ATLANTIC OCEAN... Satellite imagery and nearby buoy and ship observations indicate that a small low pressure system has formed about 435 nm east- southeast of the Georgia-South Carolina border. Please, refer to the Special Features section for more details. Elsewhere the pressure gradient between a 1029 mb Bermuda High near 38N62W and lower pressure along the ITCZ is forcing generally gentle to fresh E to SE trades south of 27N. A weak cold front has reached our northern border and stretches from 31N35W to 31N57W. Seas across the waters are generally 5-7 ft south of 23N as well as north of 27N and west of 65W. The 1013 mb low pressure near 30N73W is expected to deepen as it moves toward the South Carolina coast through late Mon, and may briefly become a tropical depression or storm before landfall. At a minimum, mariners in this area can expect strong to near gale force winds and rough seas in occasional squalls through Mon. Scattered showers and thunderstorms will persist to the southeast of this low and east of the Bahamas into Mon. Elsewhere moderate SE flow will persist through late week as high pressure builds over the area. $$ Landsea