000 AXPZ20 KNHC 030216 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 UTC Fri Nov 03 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 0000 UTC surface analysis and satellite imagery through 0215 UTC. INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends W between 09N and 10N from the Caribbean coast of Colombia to the Pacific coast of Costa Rica at 10N85W to 10N94W, then turns NW through an embedded 1009 mb surface low pressure at 15.5N112W, then SW to 13N116W, then NW again to an embedded 1010 mb low pressure at 16N131W. Scatterometer winds indicate that the monsoon trough transitions to an ITCZ from 16N131W to 11N140W. Scattered moderate convection is observed within 120 nm either side of a line from 06N78W to 11N88W. Scattered moderate isolated strong convection is noted within 240 nm either side of a line from 12N105W to 08N111W to 10N118W, and within 60 nm either side of lines from 14N122W to 16N129W and from 12N130W to 08N140W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A surface high will meander near 30N120W through Tue supporting gentle to locally moderate northerly flow, and 3 to 5 ft seas, across the waters W of the Baja Penisula. Moderate NE to E winds, and 4 to 6 ft seas, are observed across the Mexican offshore waters from 13N to 20N, with little change expected through late Fri night. Gulf of Tehuantepec: A tightening pressure gradient will result in strong to near gale force northerly drainage flow beginning tonight and continuing through Wed morning with model guidance then suggesting that the next gale event, with seas building to 12 ft, will begin on Wed evening. Gulf of California: Moderate SW flow is forecast from 29.5N to 31N overnight. Moderate NW flow expected across the gulf waters S of 26N on Fri night into early Sat. Otherwise, light and variable winds are forecast elsewhere through this upcoming weekend. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Moderate to fresh NE drainage winds, and 4 to 6 ft seas, are forecast across and 150 nm downstream of the Gulf of Papagayo tonight, with moderate flow expected on Fri and Sat nights. Model guidance is suggesting fresh drainage flow on Sun and Mon nights. Light NW-N winds, and 2 to 4 ft seas, are expected elsewhere to the N of the monsoon trough, and moderate to locally fresh southerly winds, and 4 to 7 ft seas, are forecast S of the monsoon trough. REMAINDER OF THE AREA... A 1014 mb surface low is analyzed at 30N140W, trailing a developing trough S to 26N140W. The low will move NE of the area early Fri with the trough moving E as a cold front that will reach a position from 32N130W to 22N140W late Fri, and stall from 32N124W to 21N137W on Sat night. A secondary surge of re- enforcing cold air will propagate S reaching along 32N between 135W and 140W on Fri night, with strong to near gale force northerly flow, and 8 to 12 ft seas, W of line from 32N130W to 27N140W. The N winds will diminish to a fresh N to NE breeze on Sun. A frontal wave low may develop along the stalling front near 29N129W late Sat night, and move slowly N on Sun and Mon to near 32N127W on Tue with strong N to NW winds within 150 nm over the NW quadrant of the low on Sun. $$ Nelson