000 AXPZ20 KNHC 260920 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Fri May 26 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 0900 UTC. ...TROPICAL WAVES... The southern portion of a tropical wave moving into Central America is along 84W. Scattered moderate to strong convection is observed within 240 nm west of the wave. The wave is under upper level diffluent flow which is maintaining the active convection. This wave will move slowly westward through the weekend. A weak tropical wave extends from the Yucatan peninsula to 08N94W, with active convection inland over Guatemala. This wave is expected to become diffuse and ill-defined through Saturday. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends northwestward across Central America from an area of low pressure in northern Colombia near 09N75W to 15N90W then westward to the coast of southern Mexico near 16N98W. From there it extends southwestward through a 1009 mb low near 08N117W then westward to 08N130W, where it becomes the ITCZ which extends beyond 07N140W. Clusters of scattered moderate isolated strong convection associated with the oceanic low are within 45 nm either side of the trough axis between 114W and 119W, with minimal convection elsewhere along the boundary. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A 1006 mb low is analyzed along a trough across the western part of the Gulf of California from 32N114W to 25N111W. Scatterometer data at 0427 UTC showed 25-30 kt SSW winds north of 30N associ- ated with the low and trough, which is in agreement with model guidance the past few days. Expect strong SW winds and seas to 8 ft to continue north of 30N today, then diminish late tonight. Latest scatterometer data shows gentle to moderate northerly winds west of Baja California, and gentle westerly winds south of 17N. Light and variable winds are expected in the Gulf of California this weekend, as well as south of Tehuantepec, where a weak low is expected to develop near 13N98W. Gentle NW winds and 4-6 ft seas will prevail elsewhere through Sunday. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gentle southwest to west winds prevail between the Papagayo region and Tehuantepec, with seas of 4 to 5 ft in SW swell. Expect gentle westerly monsoonal winds to spread across the coastal waters today as the tropical wave mentioned above moves across the area. Nocturnal offshore winds will pulse to fresh levels in the Gulf of Papagayo Saturday night and Sunday night behind the wave. Moderate southwest winds will continue south of 09N through Thursday night. Otherwise, little change is forecast this weekend. REMAINDER OF THE AREA... Weak troughing prevails the forecast area north of 22N. The lack of a strong ridge is also reflected in gentle to moderate trade winds north of the ITCZ indicated in recent scatterometer data. Slightly stronger high pressure northwest of the area will build southward by the end of the weekend and into early next week, supporting increasing trades to moderate to fresh levels and building seas to 5-8 ft across the waters north of the ITCZ. $$ Mundell