Tropical Weather Discussion
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952 AXNT20 KNHC 150605 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0605 UTC Sat Jun 15 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, some areas of South Florida, and the waters from the central Bahamas northward from there and also over the waters north of 25N and west of 69W: A persistent surface trough trails southwestward from low pressure (Invest AL90) that is centered well north of the area offshore the U.S. southeastern coast, southwestward to inland central Florida near Cocoa Beach to near Venice, and continues southwestward to low pressure of 1007 mb over the central Yucatan Peninsula. The trough is helping to advect ample deep tropical moisture across the southeastern Gulf of Mexico, South Florida, the Bahamas and northward. Aided by a mid to upper-level trough that just northwest of the surface trough, scattered heavy showers and strong thunderstorms continue for most areas of the above mentioned locations. Conditions are expected to improve in South Florida tonight, but shower and thunderstorms may linger over the Atlantic waters off South Florida to the NW and central Bahamas and over the southeastern Gulf of Mexico through the rest of the weekend. Anticipate dangerous 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 Central American Gyre (CAG) continues to develop. Sporadic convection capable of producing heavy showers are already occurring in the region. As the CAG develops further, more widespread deep convection is expected to develop this weekend through next Friday, June 21. Combined with persistent moist onshore flow in the Pacific coast of Chiapas State of Mexico, Guatemala, Honduras, El Salvador and northwestern Nicaragua, very significant rainfall amounts are expected. With the soil already saturated in this area, life-threatening flash flood and mudslide are probable, especially in hilly terrains. Please refer to bulletins and forecasts from your local weather forecast and emergency management offices for specific information. Heavy Rainfall across Costa Rica and Panama: The same CAG mentioned above will also produce sporadic deep convection across Costa Rica and Panama through night. Periodic heavy downpours can increase the chance of flash flood and mudslide in hilly terrain, and flooding in low lying areas. Please refer to your local weather forecast offices for more information. ...TROPICAL WAVES... A central Atlantic tropical wave has its axis near 44W from 03N to 16N. It is moving westward near 15 kt. No significant convection is present as it is moving through a dry and stable environment. A central Caribbean tropical wave has its axis along 72W south of 15N to inland eastern Colombia, moving westward around 15 kt. No significant convection is occurring over the Caribbean waters with this wave. Scattered showers and isolated thunderstorms are near the southern part of the wave in Colombia. Of note, this wave is forecast to become absorbed into the CAG discussed in the Special Features section during the weekend. ...MONSOON TROUGH/ITCZ... The monsoon trough enters passes off the coast of Africa near the Atlantic near 14N17W and continues southwestward to 07N21W and continues to 05N30W and to 06N42W. It resumes at 06N45W to 06N54W. Scattered moderate to isolated strong convection is seen south of the trough from 06N to 11N east of 17W to the coast of Africa. Similar activity is within 60 nm of the ITCZ between 17W and 27W, and within 60 to 90 nm south of the ITCZ between 30W and 44W. Convergent winds near the eastern end of the East Pacific monsoon trough is contributing to the development of scattered showers and thunderstorms, some strong, over southwestern Caribbean south of 13N west of 77W. This activity extends westward to inland Costa Rica and northern Panama and into the eastern Pacific waters. ...GULF OF MEXICO... Please read the Special Features section above for information about the ongoing heavy rainfall over the far southeastern Gulf. Aside from the features and convection described in the section above, surface ridging prevails across the remainder of the basin. Numerous moderate to isolated strong convection covers most of the Yucatan Peninsula. Scattered moderate to isolated strong convection is over the eastern Bay of Campeche. Isolated showers and thunderstorms are over the central and western portions of the Bay of Campeche. Gentle to moderate south to southeast winds are over the eastern Bay of Campeche. Gentle to moderate north to northeast winds over the rest of the basin, except for gentle east to southeast winds over the NE Gulf. Seas are 2 to 4 ft throughout, except for slightly higher seas of 3 to 5 ft over the southeastern Gulf. For the forecast, the aforementioned trough that extends from central Florida to the Yucatan Peninsula will dissipate overnight. A Central American Gyre will develop over the next couple of days. Environmental conditions appear conducive for a tropical cyclone to develop from this broad area of low pressure, and a tropical depression could form over the southwestern Gulf during the early or middle part of next week. Active convection, along with increasing winds and building seas are expected with this system in the early to mid part of next week, mainly impacting the south-central and northwest Gulf. ...CARIBBEAN SEA... Please read the Special Features section above for heavy rainfall across Costa Rica and Panama. A deep plume of tropical moisture advecting northeastward ahead of the Gulf of Mexico surface trough is present over the northwestern Caribbean. Convergent moist southerly winds are over this section of the sea. Scattered showers and isolated thunderstorms are over this same section of the sea. Moderate to fresh east to southeast winds and seas of 6 to 8 ft are over the south-central section of the sea. Gentle east to southeast winds along with seas and 3 to 5 ft seas are over the eastern and southwestern sections of the sea. Moderate to fresh east to southeast to south to southeast winds with seas of 5 to 7 ft prevail elsewhere across the sea. For the forecast, scattered showers and thunderstorms are possible across portions of the western and northwestern Caribbean over the next few days as a Central American Gyre develops. Expect increasing winds and building seas over the western Caribbean, including the Gulf of Honduras, over the upcoming weekend as the gyre develops. ...ATLANTIC OCEAN... Please read the Special Features section above for information about the ongoing heavy rainfall and hazardous marine conditions for waters near southeastern Florida and also near the NW and central Bahamas. In addition to the surface trough and associated weather described above under Special Features, a broad Atlantic ridge extends southwestward from a 1032 mb high that is located well north of the area over the north-central Atlantic to near the Lesser Antilles. The gradient related to this feature is supporting gentle to moderate east to southeast winds and seas of 4 to 6 ft north of 20N between 35W and the Florida/Georgia coast, except moderate to fresh south to southwest winds and seas of 5 to 7 ft are north of 28N between 71W and 76W. Latest ASCAT satellite data passes show fresh to strong north to northeast winds north of 13N between the coast of Africa and Cabo Verde Islands. These winds reach northward to near Canary Islands. Seas with these winds are 7 to 9 ft. For the tropical Atlantic from the Equator to 20N between 30W and the Lesser Antilles, gentle to moderate, and at times, fresh northeast to east to southeast winds are present over these waters along with seas of 4 to 7 ft. Gentle to moderate monsoonal and southerly winds with 4 to 6 ft seas in mixed moderate swell are over the rest of the Atlantic Basin. A weak surface trough extends from near 26N56W to 22N63W. Another weak surface trough extends from near 30N49W to 23N53W, and yet another weak surface trough is analyzed along 67W from 21N to 26N. No significant convection is presently occurring with these features. Only isolated showers are noted from 20N to 30N between 44W and 60W. A recently develop area of scattered showers and thunderstorms induced primarily by an upper-level trough evident from 16N to 19N between 48W and 51w. For the forecast west of 55W, scattered to numerous showers and thunderstorms persist east of a trough reaching from roughly 31N76W to central Florida. Gusty winds, higher seas and frequent lightning will be possible with this convective activity. The trough will shift to the east of the region through early next week. Looking ahead, expect fresh E winds west of 70W by late Tue as high pressure builds north of the area. $$ Aguirre