000 AXPZ20 KNHC 311541 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1541 UTC Fri May 31 2019 Tropical Weather Discussion for the eastern Pacific Ocean from the Equator to 32N, east of 140W. The following information is based on satellite imagery, weather observations, radar, and meteorological analysis. Based on 1200 UTC surface analysis and satellite imagery through 1500 UTC. ...SPECIAL FEATURES... ...Heavy Rainfall Potential Over Central America and Southern Mexico... A large, low-level cyclonic circulation that is typical for this time of the year, called a Central American Gyre, will persist across southern Mexico, Central America, and the far eastern Pacific for the next several days. Locally heavy rainfall is likely to continue over portions of Central America and southern Mexico during the next several days. These rains could cause flash flooding and mudslides in areas of mountainous terrain. Abundant moisture will persist across the region this weekend, extending into the Bay of Campeche. Please refer to your local meteorological service for more details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from southern Mexico in state of Guerrero to 09N110W to 07N125W. The ITCZ continues from 07N125W to beyond 06N140W. Scattered moderate convection is noted from north of 02N and east of 82W. Scattered moderate to isolated strong convection is noted from 10N to 15N between 90W and 103W. Scattered moderate convection is observed within 60nm of the monsoon trof and ITCZ between 115W and 135W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Broad low pressure over Guatemala is supporting moderate to fresh SW winds south of the Gulf of Tehuantepec. Convergence of the SW winds is maintaining copious showers and thunderstorms. The strong SW winds that existed yesterday have diminished some as low pressure has moved inland. These winds will continue to diminish as seas subside into the weekend. Farther north, ridging north of 20N is supporting gentle to moderate breezes across the region. Little change is expected through early next week, although fresh winds may pulse off Los Cabos. A trough will move through Baja California Norte and the Gulf of California Sat, supporting moderate to fresh SW gap winds over the northern part of the Gulf of California Fri night through Sun. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Please see the Special Features section for more information about the Central American Gyre, which will continue to bring locally heavy rain to parts of Central America and the adjacent offshore waters through the next several days. The latest model guidance indicates the Central American Gyre may finally break down early next week, which would support diminishing SW winds offshore. Broad low pressure over Guatemala will support moderate to fresh SW winds off Guatemala over the next several days as monsoon flow persists. An altimeter pass earlier today indicated seas to 9 feet off the coast of Guatemala and El Salvador associated with the SW flow and a component of SW swell. These seas will subside somewhat as the swell decreases. Another weak low pressure area will form along the coast near the border of Chiapas and Guatemala during the weekend, but no significant winds or seas are expected with this feature. Farther south, seas will build to 8 ft in SW swell between Ecuador and the Galapagos Islands late this weekend and persist through early next week. REMAINDER OF THE AREA... A ridge extends from a 1028 mb high pressure centered near 34N140W to the Revillagigedo Islands. Scatterometer data continued to show observations of moderate to fresh winds from 15N to 20N west of 130W. Concurrent altimeter data indicted seas to 8 ft in this area, likely in a broad mix of swell. Farther south, trade wind convergence is producing scattered showers and thunderstorms along the monsoon trough/ITCZ between 115W and 135W. Recent altimeter passes show seas of 8 feet just south of the equator between 110W and 120W. This long period, cross- equatorial SW swell continues to dominate much of the forecast waters east of 120W. A new set of SW swell will move into the southern waters today and propagate northward through the weekend, reaching the coasts of Mexico and Central America late Sun into Mon. Expect 8-9 ft seas south of the Equator this weekend, with 8 ft seas reaching as far north as 07N between 110W and 124W by Sat. Wave heights will gradually subside below 8 ft from west to east early next week. $$ EC/KONARIK