000 AXNT20 KNHC 291726 TWDAT 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 32N. The following information is based on satellite imagery, weather observations, radar and meteorological analysis. Based on 1200 UTC surface analysis and satellite imagery through 1700 UTC. ...SPECIAL FEATURES... ...Heavy rainfall in Central America... A Central American Gyre has developed in the eastern North Pacific Ocean. The gyre will gradually move northward, toward Central America and southern Mexico, during the upcoming weekend. The gyre will continue to push abundant moisture into parts of Central America through the weekend, and into the next week. Heavy rainfall is possible in parts of Central America, especially from northern Costa Rica northward into southern Mexico. This will bring the potential for life-threatening flash floods and mudslides for the locations that receive the greatest amounts of rainfall, especially areas of mountainous terrain. Please read the bulletins and forecasts from your local weather service for more information. ...Broad low pressure in Atlantic Ocean... A broad area of low pressure appears to be developing over the central Atlantic Ocean several hundred miles east-southeast of Bermuda. This disturbance is producing a large area of showers and thunderstorms and gusty winds. Additional development of this system is possible, and the low has a medium chance of developing into a subtropical depression tonight or on Saturday as it moves generally northward. Development is not expected after that time due to unfavorable environmental conditions. ...TROPICAL WAVES... A tropical wave is along 74W, from 19N southward, moving westward at 15 knots. Isolated showers are seen in the vicinity of the wave axis. The tropical wave will move across the western Caribbean through Sun. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from the coast of Guinea near 09N14W, to 06N22W. The ITCZ continues from 06N22W to 04N40W to near the coast of Brazil near 05N52W. Scattered moderate to strong is from 04N-09N between the coast near Liberia, Sierra Leone and Guinea to 18W. Scattered moderate convection is also seen along the ITCZ from 03N-09N between 23w-42W, and scattered moderate showers and thunderstorms extending 450 nm north of the ITCZ near Brazil. GULF OF MEXICO... An upper level trough passes through central Texas, southward, to the Isthmus of Tehuantepec of southern Mexico. A stationary front is along southern Louisiana, into Matamoros, Mexico. A surface trough extends 25N90W to 18N94W in the Bay of Campeche. There is a broad area between the stationary front and the trough with moderate to strong convection from 27N to 19N and west of 90W. Another trough is seen in the NE Gulf of Mexico from 28N82W to 24N85W. Latest ASCAT data indicates fresh to strong and brief gale winds east of the trough to 90W. This is due to the convection near the area. A weak front will stall and start to dissipate through tonight from west Florida to near Tampico Mexico. A reinforcing front will move into the northeast Gulf Sun into Mon, then stall and dissipate over the east central Gulf through late Tue. Winds and seas may increase over the southwest Gulf Tue as low pressure forms farther south. CARIBBEAN SEA... Please read the SPECIAL FEATURES section, for more information about the potential for heavy rainfall over Central America, during the next few days. Upper level low is centered north of the basin near 28N58W with a trough extending southward into the eastern Caribbean. A broad anticyclonic wind flow covers the rest of the Caribbean Sea. This is enhancing scattered showers and thunderstorms north of 15N between Puerto Rico to Cuba. Scattered moderate convection is also seen in the Lesser Antilles south of Guadalupe to Porlamar. The Pacific Monsoon trough extends from the southern Caribbean west Across Panama and Costa Rica. Scattered moderate convection extends From the coast of Nicaragua south to the coast of Panama. Check out Special Features section above for more information about the tropical wave near 74W. Winds and seas will increase in the Gulf of Honduras early next week as broad low pressure forms over northern Central America and southern Mexico. ATLANTIC OCEAN... Please read the SPECIAL FEATURES section, for more information about the potential development of a broad low in the Atlantic over the next couple of days. An upper level low is centered north of the basin near 28N58W in the Atlantic Ocean. At the surface, a 1017 mb low pressure is center is near 26N54W with a trough extending from 29N50W to 19N61W. There is a medium chance this low will develop into a subtropical depression tonight or on Saturday. Scattered moderate convection is within 220 nm NE and E of the low, in the NE quadrant. Isolated moderate is elsewhere within 240 nm to the north of the surface trough, and within 300 nm to the north of Puerto Rico and Hispaniola, in the Atlantic Ocean. Weak high pressure north of the area will shift east through Sun ahead of a cold front moving south of 30N Sun night. The front will reach from Bermuda to Palm Beach Florida on Mon, then stall and dissipate along 25N through Tue night. $$ MTorres/Christensen