000 AXNT20 KNHC 170616 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0605 UTC Thu Jun 17 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 0000 UTC surface analysis and satellite imagery through 0550 UTC. ...SPECIAL FEATURES... Shower activity associated with the broad low pressure area over the Bay of Campeche and the adjacent land areas has become a little better organized since yesterday. This system will move little tonight, and little if any development is expected during that time due to interaction with land. However, the low should begin to move northward on Thursday, and a tropical depression is likely to form by late Thursday or on Friday when the low moves across the western Gulf of Mexico. An Air Force Reserve Unit reconnaissance aircraft is scheduled to investigate the area on Thursday, if necessary. Regardless of development, heavy rainfall will continue over portions of Central America and southern Mexico during the next few days. Heavy rains should also begin to affect portions of the northern Gulf Coast on Friday. Please consult products from your local meteorological service for more information. This area has a high chance of tropical cyclone formation in the next 48 hrs. Please refer to the latest Tropical Weather Outlook issued by the NWS National Hurricane Center at www.hurricanes.gov for more details on this disturbance. ...TROPICAL WAVES... An Atlantic tropical wave axis is analyzed along 37W from 17N southward, moving W at 10 to 15 kt. Scattered showers are noted from 04N to 13N between 32W and 40W. Another Atlantic tropical wave axis is analyzed along 57W from 18N southward, moving W at 15 to 20 kt. Scattered moderate convection is noted south of 18N between 53W and 60W. A western Caribbean tropical wave axis is analyzed along 79W from 18N near Jamaica southward across Panama, moving W at 5 to 10 kt. Scattered moderate convection is noted on the western side Of the trough axis south of 14N between 79W to 83W, near the coast of Nicaragua. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through the coast of Africa near 11N16W to 08N22W. Segments of the ITCZ are analyzed from 08N22W to 09N31W, then resumes near 07N40W to the coast of Brazil near 03N50W. Scattered showers prevail near the monsoon trough and ITCZ south of 10N and east of 27W. GULF OF MEXICO... Refer to the Special Features section above for details on a broad low pressure area over the Bay of Campeche. A surface trough is analyzed from 26N89W to 20N93W. Aided by upper-level divergent flow, scattered moderate isolated strong convection is occurring across the southern half of the basin mainly south of 27N. To the northeast, a frontal boundary extends along 30N and east of 87W across the Florida Panhandle. Scattered showers prevail along the boundary and over the Florida Peninsula. Gentle to moderate S to SE winds are noted in the southeastern Gulf and west to southwestern flow in the far northeast Gulf, with mainly moderate N to NE winds in the western Gulf. Seas are 2-4 ft through the basin. For the forecast, the broad area of low pressure in the Bay of Campeche will move little tonight, and little if any development is expected during that time due to interaction with land. However, the low should begin to move northward on Thu, and a tropical depression is likely to form by late Thu or on Fri when the low moves across the western Gulf of Mexico. This area has a high chance of tropical cyclone formation during the next 48 hours. High pressure is forecast to build in across the basin in the wake of the low later in the upcoming weekend into early next week. CARIBBEAN SEA... A tropical wave is moving across the western Caribbean while another wave is approaching the Lesser Antilles. Refer to the Tropical Waves section above for details. The latest scatterometer data depicts moderate to fresh tradewinds across the eastern and central Caribbean with seas at 5 to 7 ft. Gentle to moderate E to ESE winds are detected over the NW Caribbean. Scattered moderate convection is noted north of 16N from the Gulf of Honduras north to 22N in the Yucatan Channel and west of 80W. An area of scattered showers prevails across the eastern Caribbean mainly south of 15N and east of 65W. 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 and into early next week. Moderate to fresh trades will prevail elsewhere, except light to gentle south of 11N. ATLANTIC OCEAN... A pair of tropical waves are moving westward between the west coast of Africa and the Lesser Antilles. Refer to the Tropical Waves section above for details. A diffluent flow aloft continues to support scattered moderate convection over the Florida Peninsula and western Atlantic mainly west of 70W. To the east, a surface ridge dominates the entire Atlantic forecast area anchored by the Bermuda-Azores High located north of the area, near 33N43W. Fresh to locally strong S winds are occurring north of 29N and west of 70W. Seas in this same area are ranging between 7 to 10 ft. Moderate to fresh trades dominate south of 22N with seas at 6 to 8 ft. Gentle to moderate trades prevail elsewhere with seas at 3 to 5 ft. An exception is from 20N to 25N, south of the Canary Islands, between the west coast of Africa and 28W where fresh to locally strong N-NE winds persists due to a locally tight pressure gradient. Seas are 6 to 9 ft in this area. For the forecast west of 65W, the ridge of high pressure across the area will retreat eastward Thu enabling a trough to move through the northern forecast waters through Fri. High pressure will then return to the area this weekend into early next week. $$ MTorres