Tropical Weather Discussion
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801 AXNT20 KNHC 140559 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0605 UTC Fri Jun 14 2024 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 0545 UTC. ...SPECIAL FEATURES... Heavy Rainfall over the southeastern Gulf of Mexico, portions of the Florida Peninsula, and the western Atlantic west of 72W: Ample deep tropical moisture continues to advect northeastward across the southeastern Gulf of Mexico to over South Florida as well as to over sections of central Florida and to across the western Atlantic waters, reaching eastward to near 72W. The persistent pattern of a surface trough that trails southwestward from low pressure of 1010 mb (Invest Al90) that is now near 31N78W to across central Florida from near Titusville to Sarasota and to the northern Yucatan Peninsula along with a broad mid to upper- level trough that is to the northwest of the surface trough and shifting slowly eastward will continue to sustain numerous showers and thunderstorms to the southeast of the surface trough impacting the aforementioned areas through at least Fri night. This activity will be accompanied by cloud to surface lightning, strong gusty winds, rough seas and low visibility. Mariners transiting these regions should exercise caution. Please refer to bulletins and forecasts from your local weather forecast offices for specific local information. Heavy Rainfall over Central America and Mexico: A barotropic Central American Gyre (CAG) is rapidly developing. Observations are indicating that heavy rainfall is already occurring before the main event that is forecast to begin Sunday morning, June 16 through the morning of Friday June 21. The persistence of moist onshore flow in the Pacific basins of Guatemala, Chiapas, Honduras and in El Salvador will favor 3-4 days of intermittent rounds of heavy precipitation. Please refer to bulletins and forecasts from your local weather forecast offices for specific local information. ...TROPICAL WAVES... A far eastern Atlantic tropical wave has its axis near 15 north of 03N to inland the west coast of Africa. It is moving westward at about 5-10 kt. A large area of numerous moderate to strong convection is from 06N to 11N between the coast of Africa and 18W. Similar convection is behind the wave to inland Africa near 07W. A central Atlantic tropical wave has its axis along 37W from 02N to 16N, moving westward at 15 kt. No significant convection is occurring with this wave as it is moving through a dry and stable surrounding environment. Another central Atlantic tropical wave has its axis near 55W south of 15N to inland Suriname. It is moving westward around 15 kt. No significant convection is also not being observed as it also surrounded by a dry and stable environment. This feature will likely be dropped from the 06Z surface analysis as latest model guidance and satellite animation of time series suggest that it becoming unidentifiable. An eastern Caribbean tropical wave has its axis near 66W south of 15N to inland central Venezuela. It is moving westward at 10-15 kt. No deep convection is noted with this wave over the Caribbean, however, isolated showers are possible near it. A western Caribbean tropical wave has its axis along 83W south of 15N, moving westward at 5 to 10 kt. Deep convection with this wave has shifted west to the eastern Pacific Ocean. This wave is likely not to be identified on future surface analyses as it is forecast to be absorbed into the Central American Gyre (CAG) described under Special Features. ...MONSOON TROUGH/ITCZ... The monsoon trough axis passes off the coast through southern Senegal and continues southwestward to 08N19W and to 06N21W, where it transitions to the ITCZ and extends to 06N30W to 07N40W and to 05N50W. Aside from the convection described in the tropical waves section above, scattered moderate to isolated strong convection is within 120 nm north of the ITCZ between 43W and 50W. ...GULF OF MEXICO... Please read the Special Features section above for information about the ongoing heavy rainfall over the southeastern Gulf of Mexico and on an upcoming heavy rainfall event to impact some areas of southeastern Mexico. A stationary front inland northern Florida extends into the western Florida panhandle. From there, it transitions to a warm front into a 1011 mb low over eastern Louisiana. A dissipating stationary front extends from the low to just offshore southwestern Louisiana and to inland northeast Texas. A surface trough stretches NE to SW across central Florida from near Titusville to Sarasota. It continues southwestward to inland the Yucatan Peninsula, where a 1007 mb low is centered near 19N89W. Scattered to numerous showers and thunderstorms southeast of the trough continue to impact most of the southeastern Gulf, Straits of Florida and western Cuba. Similar activity is increasing over the Yucatan Peninsula. Outside of convection, light to gentle variable winds prevail west of the trough, with moderate south to southwest winds east of the trough. Seas are 1 to 3 ft west of the trough, and 3 to 4 ft east of the trough. Some light haze is over sections of the SW Gulf due to ongoing agricultural fires are in Mexico. For the forecast, the aforementioned trough is expected to gradually weaken through late Fri. Looking ahead, a broad area of low pressure is forecast to form over the southwestern Gulf of Mexico late this weekend or early next week. Environmental conditions appear conducive for gradual development of this system, and a tropical depression could form during the early or middle part of next week while it moves slowly westward or west- northwestward. Increasing winds and building seas are expected with this system. ...CARIBBEAN SEA... Please read the Special Features section above for more information about the upcoming heavy rainfall event over Central America. The pressure gradient between Atlantic high pressure, lower pressures in the deep tropics, and the trough of low pressure across the southeastern Gulf of Mexico is resulting in moderate to fresh east to southeast winds over most of the basin, except for the waters north of Colombia, where winds are fresh to strong per latest ASCAT satellite data passes over that section of the sea. Seas range from 6 to 9 ft over the central Caribbean and 4 to 6 ft elsewhere, except 3 to 5 ft east over the southwestern Caribbean. For the forecast, fresh to strong trade winds will prevail across the south-central Caribbean through Fri. Moderate to fresh southeast winds are expected over the northwestern Caribbean through Fri. Otherwise, scattered showers and thunderstorms are forecast to continue across portions of the northwestern Caribbean through the rest of the week as a surge of tropical moisture persists across the region. Expect increasing winds and building seas over the western Caribbean, including the Gulf of Honduras, over the upcoming weekend as a broad area of low pressure is forecast to form over the southwestern Gulf of Mexico. ...ATLANTIC OCEAN... Please read the Special Features section above for more information about the heavy rainfall over the western Atlantic and near and over portions of the Florida peninsula. A 1010 mb low is near 31N78W, with a trough extending southwestward to inland central Florida near Titusville. A stationary front behind it is analyzed from near 31N80W to inland northeast Florida near Jacksonville. Plentiful deep atmospheric is present to the southeast of stationary front and trough. Numerous showers and thunderstorms are noted west of about 72W. This activity extends westward to the Straits of Florida and to sections of central Cuba. Over the central Atlantic, a trio of troughs is analyzed: The first one is near 63W from 22N to 28N, the second one from just east of Barbuda northeastward to 20N58W and to 23N57W and the third one from 22N48W northeastward to 26N45W and to near 31N44W. Scattered showers and isolated thunderstorms are seen from 21N to 24N between 52W and 59W, and from 23N to 27N between 46W and 49W. Fresh to strong winds and 5 to 7 ft seas are north of 27N W of 73W. Elsewhere, strong high pressure of 1033 mb located well north of the discussion area near 38N36W. Its associated ridge reaches southwestward to the central Bahamas. Gentle to moderate winds and seas of 3 to 6 ft seas dominate the basin west of 35W. Moderate to fresh trade winds east of 35W, except for fresh to strong northeast winds from the Cabo Verde Islands to the Canary Islands, including along the coast of Africa. Seas are 5 to 7 ft across this area. Saharan Air dominates the lower to middle atmosphere across the Atlantic from about 10N to 20N and roughly between Africa and the Lesser Antilles. For the forecast west of 55W, the numerous showers and thunderstorms west of 72W should continue through at least Fri. Fresh to strong southerly winds are expected over the western Atlantic ahead of this system through early Sat. As the low pressure departs, high pressure will build southward over the western Atlantic beginning this weekend and into early next week. $$ Aguirre