000 AXPZ20 KNHC 182145 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2017 UTC Tue Jun 18 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 1800 UTC surface analysis and satellite imagery through 2100 UTC. ...TROPICAL WAVES... A tropical wave with axis along 92W and north of 04N to inland western Guatemala is moving westward at 10-15 kt. No significant showers and thunderstorms are noted with this wave. A tropical wave stretches from near 15N104W to 05N106W, moving westward at 10-15 kt. This afternoon, scattered to numerous moderate to strong convection persists in association with this wave from 102W to 110W between 06N and 15N. A tropical wave with axis along 120W from 04N to 15N is moving westward at 10-15 kt. Scattered moderate convection 210 nm both east and west of the wave between 06N and 14N. A tropical wave with axis along 136W from 04N to 15N is moving westward at an estimated speed over the past 24 hours of 10 kt. Only isolated showers and thunderstorms are associated with this wave in the vicinity of its axis, and this wave is expected to weaken over the next 24 hours. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends northern Costa Rica near 10N85W to 08N95W to 12N110W TO 10N135W. Outside of shower and thunderstorm activity discussed above under the Tropical Waves section, little shower and thunderstorm activity is occurring. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Scatterometer data from 18 UTC shows gentle to moderate breezes across offshore waters as high pressure dominates over the region. An altimeter satellite pass from earlier this afternoon indicated seas in this region generally range from 4 to 5 feet. Little change is expected as the high pressure ridge will remain in place through the week. Low pressure over the Colorado River Valley will strengthen some toward the end of the week, and a surface trough will continue to extend from this low over Baja California. This will cause winds to increase over the northern Gulf of California at the end of the week. Some northwesterly swell will also build seas off Baja California Norte for the end of the week and weekend. Farther south, a weak tropical wave will move west across the southern Mexico offshore waters, with little impact on local weather, aside from enhancing overnight coastal showers and thunderstorms. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Scatterometer data from earlier today show gentle to moderate breezes occurring on offshore waters. The tight pressure gradient between high pressure north of the Caribbean Sea and lower pressure through the tropics will support fresh to strong gap winds across the Gulf of Papagayo region during overnight hours through Wednesday night, then again this weekend. Seas will generally be dominated by moderate cross-equatorial southwest swell. REMAINDER OF THE AREA... Latest scatterometer data showed moderate to fresh winds to the south of a high pressure centered near 40N140W, with the ridge extending southeastward toward the Revillagigedo Islands. Seas in the region, according to 16 UTC altimeter satellite passes, are around 5 to 7 feet in this region, except 8 to 9 feet north of 25N and west of 125W, where northerly swell is propagating into the region. This swell, mainly associated with gale force winds well north of the region, will continue to produce seas of 8 to 10 feet north of 27N and west of 125W through the end of the week. Farther south, long-period cross-equatorial swell of 8 to 10 feet is impacting areas south of 05N and west of 100W, according to afternoon altimeter satellite data. Seas area expected to remain at this level through early Thursday, before decaying. Another increase in swell is expected in the area by this weekend. $$ Konarik