000 AXPZ20 KNHC 150938 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 938 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 0600 UTC surface analysis and satellite imagery through 0900 UTC. ...TROPICAL WAVES... The axis of a tropical wave is near 80W, drifting west at 5 to 10 kt. No significant convection is observed near the wave axis. The axis of a tropical wave is near 92W, drifting west at 5 to 10 kt. Scattered showers are evident within 60 nm west of the wave axis from 08N to 11N. The axis of a tropical wave is near 109W, moving west around 15 kt. Scattered moderate convection is noted from 06N to 11N within 60 nm east of the wave axis. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from near 11N85W to 09N95W to 12N110W to 10N120W. The ITCZ continues from 10N120W to 07N130W to 09N140W. Scattered moderate isolated strong convection is noted within 90 nm of the monsoon trough axis between 95W and 125W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... The mid to upper level pattern remains fairly amplified. A long- wave, upper trough reaching from the Florida Panhandle to south of Tampico, Mexico is interacting with a tropical wave 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 into 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 10 ft in the plumes 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 possible Tue night into the far northern Gulf of Tehuantepec 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 group 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 set of SW swell is expected later in the week. REMAINDER OF THE AREA... A ridge extends from 1028 mb high pressure centered near 34N145W 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 7 ft seas prevailing. Another round of southerly swell will enter the area late in the week. $$ Christensen