000 AXPZ20 KNHC 162129 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2026 UTC Tue Jun 16 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 1800 UTC surface analysis and satellite imagery through 2040 UTC. ...TROPICAL WAVES... A tropical wave is along 88W-89W, moving west at 10 kt. Scattered moderate isolated strong convection is active N of line from 05N80W to 07N93W, and extends northward across the W Caribbean Sea, coastal portions of Nicaragua and Honduras, and the Yucatan Peninsula. A low amplitude tropical wave is along 100W-101W, moving west 5-10 kt. Scattered to numerous moderate to strong convection is ongoing from 06.5N to 13N between 94.5W and 107W. A tropical wave is analyzed along 116W-117W, moving west around 10 to 15 kt. Scattered moderate to strong convection is noted from 06N to 15N between 108W and 128W. TPW animations and active convection W of 118W suggest that this wave may now be along 121W-123W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 09.5N74W to 09N85W to 10N110W to 13N117W to 10N131W. The ITCZ continues from 10N131W to 09N140W. Convection associated with tropical waves is described above. Scattered moderate isolated strong convection is noted from 07N to 11N between 128W and 140W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... The mid to upper level pattern remains fairly amplified across the region between the Bahamas and 120W. A long-wave, upper trough reaches from the northeast Gulf of Mexico to the central Bay of Campeche and across the Gulf of Tehuantepec region. This upper trough is interacting with the tropical wave along 88W-89W to deepen a resident trough over the Yucatan peninsula and southwest Gulf of Mexico. This is maintaining 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. An afternoon scatterometer satellite pass indicated 20-25 kt winds in the Gulf of Tehuantepec. These winds are pulsing, with the strongest pulses occurring during the overnight hours with the help of local drainage effects. Wave heights are currently estimated to be 7 to 9 ft. These seas are mixing with longer period SW swell persisting in the region. This pattern will continue into Wed. 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 central Rockies through the northern Gulf of California and acrossBaja California Norte. This pattern is tightening the pressure gradient between lower pressure over northwest Mexico and higher pressure west of the area. This resulted in fresh to strong westerly gap winds overnight over the northern Gulf of California, that have diminished to 15-20 kt from the S to SW this afternoon. Meanwhile NW swell producing seas of 6 to 7 ft persists in the outer offshore waters of Baja California Norte. This will briefly increase to 7-8 ft late this afternoon and evening, then subside tonight, before another pulse of NW swell to 8 ft will enter the waters northwest of 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. 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, mainly south of Panama. This will subside through mid week, but another round of SW swell is expected later in the week. REMAINDER OF THE AREA... A ridge extends from 1033 mb high pressure centered near 36N143W E-SE to offshore of Cabo Corrientes near 16N108W. The pressure gradient between this area of high pressure and lower pressure in the vicinity of the ITCZ is supporting fresh trade winds from 09N to 20N west of 127W. Seas are in the 7 to 9 ft range over this area in a mix of swell. Moderate to fresh winds, and seas of 5 to 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 6 to 8 ft seas prevailing. Another round of southerly swell will enter the area late in the week. $$ Stripling