000 AXPZ20 KNHC 200128 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 105 UTC Thu Jun 20 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 0200 UTC. ...TROPICAL WAVES... A tropical wave with axis along 99W from 04N to 15N is moving westward at 10-15 kt. Scattered moderate convection has developed with this wave from 05N to 10N between 90W and 99W. A tropical wave with axis along 122W from 04N to 15N is moving westward at 15 kt. Scattered moderate convection exists from 05N to 15N between 115W and 125W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from a 1007 mb low over northern Colombia westward to 09N79W to 08N95W to 13N111W, to where it transitions to the ITCZ to 10N130W. The ITCZ then continues through 10N140W. Outside of convection discussed above under the Tropical Waves section, scattered moderate convection exists within 120 nm of the trough between 79W and 90W, and from 125W to 130W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Afternoon scatterometer data continue to show gentle to moderate northwest wind across offshore waters as weak high pressure dominates E of 135W. Altimeter satellite passes at both 16 UTC and 18 UTC indicated seas of 7 to 8 feet were being observed 120 NM and greater offshore Baja California Norte, with lesser seas elsewhere. These higher seas deriving from gales off the western coast of the United States, and will continue as northerly swell impacts the region through the remainder of the week. Elsewhere, the high pressure will remain in control, keeping little changes from occurring. Low pressure over the Colorado River Valley will strengthen some Friday, 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, possibly reaching to near gale force on Fri night. 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... Gentle to moderate breezes will prevail over most of the water into the weekend. However, pulses of wind of 20 to 25 kt is expected during the overnight hours tonight, and again Friday night into early next week in the area near Papagayo. These gap winds are due to a tight pressure gradient between high pressure north of the Caribbean sea and the lower pressure associated with the monsoon trough. Altimeter satellite scans from 14 UTC show Seas of 4 to 6 FT will prevail as southerly swell will continue to be dominant into the weekend. REMAINDER OF THE AREA... A 1033 mb high remains quasi-stationary well north of the area near 40N140W, with a ridge extending southward to the tropical region west of 120W. South of this ridge, easterly wind of 15 to 20 kt is occurring, and these trade winds should persist through the weekend. North of 26N, seas of 8 to 10 feet are occurring, according to an 18 UTC altimeter satellite scan, due to northerly swell forming in gales off the west coast of the United States. This swell will continue for the next several days. Farther south, long-period cross-equatorial swell is causing seas of 8 to 9 feet. This swell will decay some toward the end of the week, before new swell arrives this weekend, again increasing seas south of 08N to 8 to 10 feet. $$ KONARIK