000 AXPZ20 KNHC 051530 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1530 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 1200 UTC surface analysis and satellite imagery through 1500 UTC. ...TROPICAL WAVES... A tropical wave reaches from 08N103W to 13N104W, moving west 10 to 15 kt. The wave remains poorly depicted at the surface, but continues to show up well in the lower to mid levels of the atmosphere via satellite derived winds. Placement is on the leading edge of an area of deep layer moisture. The wave is interacting with the monsoon trough, and enhancing scattered showers and a few thunderstorms from 05N to 12N between 95W and 105W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from 10N85W to 12N93W, then resumes from 11N97W to 08N127W. The intertropical convergence zone axis continues from 08N127W to 06N135W to beyond 07N140W. Scattered moderate convection is noted from 05N to 12N between 95W and 105W. Scattered moderate and isolated strong convection is present from 07N to 11N between 85W and 90W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A pair of recent altimeter satellite passes indicated seas to 8 ft north of the area off the coast of southern California. This is related to strong northerly winds that are generating swell of 8 to 10 ft. Some of this swell is starting to propagate south 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 west 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 south, 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 south 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 south of western Panama Thursday and Friday as south to southwest flow becomes fresh, then subsiding through Saturday. REMAINDER OF THE AREA... Recent altimeter satellite data indicates seas to 8 ft pushing south of 32N this morning. This is northerly swell related to fresh to strong winds north of the area, generated between 1028 mb high pressure centered near 39N130W and low pressure and troughing over California. Moderate to fresh northerly winds are reaching as far south as 27N between 120W and 125W. The high pressure will weaken and shift south through mid week ahead of a late season frontal boundary moving eastward to the north of the discussion area. This will maintain generally gentle to moderate trade wind flow farther south in the deep tropics. Outside of the area of northerly swell, seas north of 20N are generally 4 to 6 ft. Farther south, trade wind related seas have been diminishing over the past couple of days, but component of cross-equatorial southerly swell is propagating into the region allowing at least 7 ft seas west of 120W, and 8 to 9 ft south of 08N between 110W 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 west of 125W and north of the ITCZ to 20N. The stronger high pressure will remain in place through next weekend. $$ CHRISTENSEN