000 AXPZ20 KNHC 151613 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Mon Jun 15 2020 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 1520 UTC. ...TROPICAL WAVES... A tropical wave is along 83W, moving west at 10 kt. Scattered moderate to strong convection is noted N of 05N E of 88W extending to 18N across the western Caribbean Sea. The majority of this convection is occurring behind the wave axis. A tropical wave is relocated to along 96W, drifting west at 5 to 10 kt. Scattered showers and isolated thunderstorms are noted near the wave axis within 150 nm of the monsoon trough. A tropical wave is along 110W, moving west around 10 kt. Scattered moderate isolated strong convection is noted ahead of the wave axis from 09.5N to 14N between 108W and 128W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from near 09N75W TO 10N85W TO 09N98W TO 12N110W TO 10N121W. The ITCZ continues from 09.5N121W TO 06N131W TO 06.5N140W. Convection associated with tropical waves is described above. Elsewehre scattered moderate isolated strong convection is noted from 09N TO 12.5N between 93W and 103W. Scattered moderate convection is noted from 04.5N TO 08N between 119W and 140W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... The mid to upper level pattern remains fairly amplified. A long- wave, upper trough reaching from the NE Gulf of Mexico to south of Tampico, Mexico is interacting with the tropical wave along 83W to deepen a resident surface trough over the Yucatan peninsula. This is resulting in a tight pressure gradient between the trough and higher terrain over southern Mexico, allowing strong northerly gap winds to funnel across the Gulf of Tehuantepec. These winds are pulsing, with the strongest pulses occurring during the overnight hours with the help of local drainage effects. Seas are reaching 8 to 9 ft in the current plume of northerly winds emerging out of the Gulf of Tehuantepec into the open Pacific. These seas are mixing with longer period SW swell persisting in the region. This pattern will continue into mid week. By late week, the upper trough will have dampened out and moved east, allowing the gap wind flow and related seas to diminish. Farther north, another mid to upper trough reaches from the northern Rockies through southern California. Fresh to strong westerly gap winds are expected Tue night into the far northern Gulf of California as the axis of the mid to upper trough shifts eastward over the area. NW swell of 6 to 8 ft persists in the outer offshore waters of Baja California Norte. This will subside through today, but another pulse of NW swell to 8 ft will enter the waters near Guadalupe Island by mid week. Looking ahead, moderate to fresh NW winds are possible off Baja California Sur by late week as a ridge builds into the area. Areas of smoke from agricultural and forest fires may impact visibility over the coastal waters of Mexico from Acapulco to Mazatlan. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gentle to moderate SW monsoon flow prevails south of the monsoon trough, with gentle to moderate winds to the north of the monsoon trough. Seas are in the 5-7 ft range. SW swell, with seas to 8 ft, is moving northward off Colombia. The swell should reach the waters off Panama through Tue. Another round of SW swell is expected later in the week. REMAINDER OF THE AREA... A ridge extends from 1029 mb high pressure centered near 34N146W E-SE to near the Revillagigedo Islands. The pressure gradient between this area of high pressure and lower pressure in the vicinity of the ITCZ is supporting fresh to strong trade winds from 10N to 20N west of 135W. Seas are in the 8 to 10 ft range over this area. Moderate to fresh winds, and seas of 5-7 ft, prevail elsewhere north of the monsoon trough/ITCZ. Moderate southerly flow prevails south of the monsoon trough/ITCZ. Long-period southerly swell still dominates the waters south of 10N and east of 110W, with 5 to 8 ft seas prevailing. Another round of southerly swell will enter the area late in the week. $$ Stripling