000 AXPZ20 KNHC 090926 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Wed Aug 9 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 0600 UTC surface analysis and satellite imagery through 0845 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... Monsoon trough from 13N105W to 12N120W 10N128W, to a 1012 mb low pressure center that is near 12N140W. Convective precipitation: scattered strong from 03N to 06N between the coast of Colombia and 78W, and from 04N to 13N between 84W and 92W. Scattered moderate to isolated strong within 120 nm to the north of the monsoon trough between 105W and 112W, and elsewhere within 300 nm to the south of the monsoon trough between 104W and 135W. Isolated moderate to locally strong within 210 nm to the north of the monsoon trough from 131W westward. Scattered moderate to isolated strong within 120 NM of the coast of Mexico between 94W and 107W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... The Gulf of California: mainly gentle to occasionally moderate southerly flow will prevail. Expect northerly wind flow in the southern part, just after 48 hours. The sea heights will be 2 feet or less, except up to 4 feet near the entrance. Gentle onshore winds and 4 to 6 feet sea heights will prevail across the offshore waters E of Jalisco to Guatemala through Saturday. Southerly swells will builds seas to 6 to 9 ft thereafter. Gentle to moderate NW-N flow will prevail across the offshore waters of Baja California into early Friday, along with seas of mainly 4 to 6 ft. It is possible that an area of low pressure, or a trough, may form in the area that runs from 13N to the southernmost point of Baja California between 100W and 110W. The start time of the beginning of the development of the possible area of low pressure is near the end of the 48-hour forecast period, roughly about sunrise on Friday. The possible area of low pressure is forecast to move NW during the weekend. Uncertainty remains with regard to the strength and impacts of any associated marine conditions. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Moderate southerly winds are expected to the S of the monsoon trough, with gentle and variable winds N of the monsoon trough. Seas will mainly range from 4 to 6 ft. It is possible that a set of long-period southerly swell, that is at the coastal areas of Costa Rica and Panama, may be producing occasional waves of 7 to 8 ft or higher in the shallow waters at the coast. The swell energy will start to decay after sunrise, and continue to decay during the next few days. A new and larger set of southerly swell will cross 03.4S from 120W, on Friday afternoon, possibly reaching the coastal waters of Panama and Costa Rica between 80W and 88W on Sunday around midnight, and possibly reaching the coastal waters that are between El Salvador and Mexico between 90W and 102W by sunrise on Monday. It is possible that the sea heights may range from 7 feet to 10 feet across the offshore waters, except in the lee of the Galapagos Islands. REMAINDER OF THE AREA... A weak 1012 mb low pressure center is near 12N140W, and it will move W of the area later this morning before dissipating. A weak and broad ridge extends from 30N140W to 26N136W and 17N123W. Gentle to moderate trades prevail N of the convergence zone, with moderate to fresh southerly winds S of the convergence zone. The sea heights are 4 to 5 ft N of the convergence zone, and 5 to 7 ft S of the convergence zone. Little overall change in these marine conditions is expected into the upcoming weekend. $$ mt