000 AXPZ20 KNHC 052121 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2121 UTC Mon Jun 5 2017 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 reaches from 09N102W to 16N103W, moving west 10 to 15 kt. A recent scatterometer pass did show an indication of the wave in the low levels. The placement is on the leading edge of an area of deep layer moisture. The wave is interacting with the monsoon trough, and enhancing convection as is described in the next section. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from 10N98W to 07N114W to 09N124W to 08N127W. The intertropical convergence zone axis continues from 08N127W to 06N133W to 08N140W. Scattered moderate to strong convection is from 06N to 13N between 86W and 92W, and also from 05N to 10N between 100W and 109W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Recent observations indicated seas of 8 to 10 ft N of 29N to off the coast of southern California. These seas are related to strong northerly winds and will continue to propagate S of 32N into the waters beyond 200 nm off Baja California Norte, near Guadalupe Island. Elsewhere off the coast of the Baja California peninsula, seas are 5 to 7 ft. Persistent ridging over the area will maintain gentle to moderate west to northwest winds through late in the week, although fresh to locally strong winds will occur mainly at night near Los Cabos Thursday through Saturday, and off Baja California Norte by Saturday as the pressure gradient tightens W of troughing over the Gulf of California. Gentle to moderate southerly breezes will persist over the the northern Gulf of California through the week as a weak trough persists. Farther S, a few showers and thunderstorms may form between the monsoon trough and 15N near the northern portion of a tropical wave migrating westward. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Convergence of light southwest flow into the monsoon trough and opposing drainage flow along coastal terrain of Central America will generate scattered to numerous mainly overnight showers and isolated thunderstorms primarily north of 04N along the coastline. Gusty winds and rough seas will be possible in and near showers and thunderstorms. Light to gentle winds will prevail generally north of 10N with 4 to 6 ft seas. Moderate south to southwest winds are expected S of 10N with corresponding seas of 5 to 7 ft as cross-equatorial southwest swell augment combined seas. Seas will peak between 8 and 9 ft S of western Panama Thursday and Friday as S to SW flow becomes fresh, then subsiding through Saturday. REMAINDER OF THE AREA... Recent observations indicated seas of 7 to 9 ft pushing S of 32N. This is northerly swell related to fresh to strong winds north of the area, generated between 1025 mb high pressure centered near 35N133W and low pressure and troughing over California. Moderate to fresh northerly winds are reaching as far south as 27N between 120W and 135W. The high pressure will weaken and shift S through mid week ahead of a late season frontal boundary moving eastward to the N of the discussion area. This will maintain generally gentle to moderate trade wind flow farther S in the deep tropics. Outside of the area of northerly swell, seas N of 20N are generally 4 to 6 ft. Farther S, trade wind related seas have been diminishing over the past couple of days, but a component of cross-equatorial southerly swell is propagating into the region allowing at least 7 ft seas W of 120W, and 7 to 9 ft S of 08N between 91W and 120W. The southerly swell will gradually decay, allowing seas to subside below 8 ft by late week. High pressure will gradually rebuild on Thursday and Friday and bring moderate to fresh trade winds to the area W of 125W, and N of the ITCZ to 20N. The stronger high pressure will remain in place through next weekend. $$ LEWITSKY