000 AXPZ20 KNHC 300236 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0236 UTC Thu May 30 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 0000 UTC surface analysis and satellite imagery through 0220 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 the far eastern tropical Pacific and Central America 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. Please refer to your local meteorological service for more details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from the coast of Nicaragua near 12N87W to 1007 mb low pressure near 14N96W to 09N110W to 07N127W. The ITCZ continues from 07N127W to beyond 06N140W. Scattered moderate convection is noted within 360 nm SE quadrant of low center and within 120 nm of the monsoon trough between 102W and 105W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Fresh to strong winds likely persist south of 1007 mb low pressure centered near 14N96W. Altimeter data from 20Z confirmed 8-12 ft seas south of the low center. Seas greater than 8 ft with fresh to strong winds will continue over the southern waters through Fri as the low tracks northeast and eventually moves inland over the isthmus of Tehuantepec. Tropical development, if any, should be slow to occur during the next day or so before the system moves inland over southern Mexico. Elsewhere, a small area of 8 ft seas is found over the outer Baja California Norte offshore waters in mixed NW and SW swell. This residual wave energy will decay through Thu with seas falling below 8 ft by Fri. Gentle to moderate NW breezes will prevail over the Baja California waters through the weekend with seas less than 8 ft. Gulf of California: Light to gentle breezes will prevail over the Gulf of California through Thu night. Moderate to fresh S to SW winds will develop in the northern Gulf Fri and continue through Sat night as an area of low pressure develops over the region. 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 rains to parts of Central America and the adjacent offshore waters through the next several days. Low pressure off the coast of southern Mexico is producing fresh to strong SW winds over the waters south of Guatemala. Based on earlier altimeter data, seas likely peak around 12 ft near 11N95W with 8 ft seas extending eastward to the offshore waters off Nicaragua. The enhanced SW monsoon flow will persist off the coast of Guatemala with fresh winds expected into the weekend, while seas will gradually subside as the low tracks inland over southern Mexico. Elsewhere, a set of SW swell will move into the Galapagos offshore waters Fri night and maintain 8 ft seas through the weekend and into early next week. Looking ahead, the Central American Gyre may finally begin weakening and move westward early next week, which could allow SW winds to diminish offshore. REMAINDER OF THE AREA... A ridge extends southeastward from 1030 mb high pressure near 33N139W to the Revillagigedo Islands. Earlier scatterometer data showed fresh NE trade winds between the ridge and the ITCZ generally west of 130W. Associated seas in this region likely remain 7-8 ft based on earlier altimeter data. Moderate to fresh trades will prevail over this area for the next several days with little change in the overall pattern expected through the weekend. Long period, cross-equatorial SW swell continues to dominate much of the forecast waters south of 20N and east of 125W. Seas 8 ft or greater cover much of the area from 05N to 14N between 87W and 105W. Seas will gradually subside over the next couple of days as low pressure tracks toward southern Mexico and wind speeds diminish over the area. Another set of SW swell will move into the far southern waters Thu and maintain 8 ft seas south of the Equator through the weekend. $$ Reinhart