000 AXPZ20 KNHC 192120 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2007 UTC Wed Jun 19 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 97W from 04N to 15N is moving westward at 10-15 kt. No significant convection is associated with this wave. A tropical wave with axis along 119W from 04N to 15N is moving westward at 15 kt. Convection consists of the scattered moderate to isolated strong type within 120 nm east and west of the wave from 04N to 14N. ...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, numerous moderate to strong convection is noted within 150 nm south of the trough between 79W and 94W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Afternoon scatterometer data continues to show gentle to moderate northwest wind across offshore waters as weak high pressure dominates E of 130W. Altimeter satellite scans from 14 to 16 UTC show seas are 4 to 5 feet, except for waters offshore Baja California Norte, where seas of 5 to 7 feet are observed. These seas are 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... Midday scatterometer data revealed gentle to moderate breezes across offshore waters. Winds have diurnally diminished near the Papgayo region, but are expected to increase again overnight to 20-25 kt. This pulse is due to a tight pressure gradient between high pressure north of the Caribbean sea and the lower pressure associated with the monsoon trough. This gradient will persist and these gap winds will continue each night into the weekend. Altimeter satellite scans from 14 UTC show that seas of 4 to 6 feet are common, and these seas 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 9 feet are occurring, according to 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, indicated on multiple earlier day altimeter satellite passes south of 08N. 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/NATIONAL HURRICANE CENTER