000 AXNT20 KNHC 151045 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1205 UTC Tue Jun 15 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 0600 UTC surface analysis and satellite imagery through 0720 UTC. ...SPECIAL FEATURES... Tropical Storm Bill is centered near 38.5N 67.2W at 15/0900 UTC moving NE at 27 kt. Estimated minimum central pressure is 999 mb. Maximum sustained wind speed is 45 kt with gusts to 55 kt. Bill is a sheared tropical storm and scattered to numerous moderate convection is noted from 37N to 41N between 62W and 69W. Bill is forecast to maintain strength through the afternoon, then is forecast to weaken by late tonight, becoming extratropical by Wed afternoon. Please read the latest NHC Public Advisory at https://www.nhc.noaa.gov/text/MIATCPAT2.shtml and Forecast/ Advisory at https://www.nhc.noaa.gov/text/MIATCMAT2.shtml for more details. ...TROPICAL WAVES... The axis of an Atlantic tropical wave is analyzed near 24W from 17N southward including across the Cabo Verde Islands, moving W at 15 to 20 kt. A 1010 mb surface low is analyzed ahead of the tropical wave near 08N25W. There is no significant convection noted with the tropical wave or low, however scattered to numerous showers are evident from 02N to 17N between 19W and 29W. This area has a low chance of developing into a tropical cyclone over the next five days. The axis of an Atlantic tropical wave is analyzed near 44W from 04N to 19N, moving W at 15 to 20 kt. There is no significant convection noted with this tropical wave, however scattered to numerous showers are evident from 12N to 21N between 38W and 47W. The axis of a Caribbean tropical wave is near 66W from 17N southward to across central Venezuela, moving W at 15 to 20 kt. There is no significant convection noted over water with this tropical wave, however deep convection is occurring over portions of Venezuela. The axis of an exiting Caribbean tropical wave is near 89W across western Belize from 18N southward, moving W at 5 to 10 kt. Deep convection is not occurring right near the wave axis in the NW Caribbean, however there is a significant band of scattered moderate and isolated strong convection from 09N to 19N between 83W and 87W, including over eastern Honduras and Nicaragua, and also from 10N to 13N between 75W and 83W. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through the coast of Africa near Guinea- Bissau to 12N16W to 06N39W. The ITCZ then continues from 06N41W to the NE coast of Brazil near 04N51W. Scattered moderate convection is noted from 01N to 06N between 09W and 19W. Similar convection is noted in a band within 105 nm north of a line from 12N43W to 08N50W to 08N55W. GULF OF MEXICO... A broad low pressure area of 1009 mb is nearly stationary and centered near 19N95W over the Bay of Campeche, accompanied by a surface trough extending from 22N98W near Tampico, Mexico through the low to 18N91W. Scattered moderate and isolated strong convection is noted in the Bay of Campeche south of 21N/22N. Fresh to strong NW winds are noted west of the trough, with moderate to fresh E-SE winds east of the trough. Otherwise, a broad and weakening ridge extends from near the Straits of Florida to the lower Texas coast. Scattered showers and isolated thunderstorms are noted across the SE and NE Gulf, including across portions of the Florida Peninsula, associated with a mid-level trough. Light to gentle anticyclonic winds were noted by earlier ASCAT data north of 24N and west of 87W, with moderate to locally fresh winds elsewhere. Seas are 3 ft or less across the basin, except locally 4 to 5 ft west of the trough. For the forecast, weak high pressure ridging over the central Gulf of Mexico will shift east through mid-week. Gradual development of a broad area of low pressure in the Bay of Campeche is possible during the next couple of days while it meanders near the coast of Mexico. The system should begin to move northward by midweek, and a tropical depression is likely to form late in the week when the low moves across the central or northwestern Gulf of Mexico. CARIBBEAN SEA... Refer to the tropical waves section above for information on any significant convection. Fresh to strong trades continue in the S central Caribbean, with moderate to fresh trades elsewhere, except gentle E-SE winds in the SW Caribbean south of 11N. Seas of 4 to 6 ft prevail across the basin, except locally 7 ft in the S central Caribbean, and 2 to 4 ft in the SW Caribbean south of 11N. For the forecast, a ridge of high pressure north of the basin combined with lower pressure over Central America and Colombia will support pulsing fresh to strong trades over the S central Caribbean and Gulf of Honduras through the upcoming weekend. Moderate to fresh trades will prevail elsewhere, except light to gentle south of 11N. A tropical wave in the eastern Caribbean will cross the central Caribbean mid-week, then the western Caribbean at the end of the week. ATLANTIC OCEAN... Refer to the Special Features section above for details on Tropical Storm Bill located well north of the discussion area. Scattered showers and thunderstorms extend across the SW N Atlantic west of 70W, including across the central and NW Bahamas, and the Florida Peninsula. Ridging dominates the basin, anchored by the Azores High north of the area. Moderate to fresh southerly return flow is noted north of 27N and west of 65W, with moderate to locally fresh E-SE flow south of 27N and west of 55W. Moderate to locally fresh trades prevail north of the ITCZ/monsoon trough to around 25N, with gentle to moderate anticyclonic winds elsewhere. An exception is west of the African coast south of the Canary Islands where a tight pressure gradient continues to support fresh to locally strong N-NE winds from 18N to 28N east of 26W. Seas of 4 to 7 ft dominate the Atlantic waters, except 6 to 9 ft seas in the area of fresh to strong winds. A large area of Saharan dust covers the tropical Atlantic westward to eastern Caribbean. Both the GOES Geocolor imagery and Sahara Dust imagery from CIMSS indicate this feature. For the forecast west of 65W, a ridge of high pressure along 27N will continue to weaken and sink southward today. Winds will be fresh to strong north of 28N through mid-week as a pair of cold fronts move by north of the area. $$ Lewitsky