000 AXPZ20 KNHC 080947 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Fri Sep 08 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 0945 UTC. ...TROPICAL WAVES AND TROPICAL LOWS... A tropical wave is analyzed to the N of 07N along 96W and has been moving W at 12 kt. Scattered moderate isolated strong convection is currently observed to the s of 10N within 240 nm E of the wave and within 120 nm W of the wave axis. Similar convection is observed within 30 nm of line from 13N90W to 15.5N94W. A 1011 mb surface low is embedded within the monsoon trough at 15N111.5W. Scattered moderate convection is flaring within 30 nm of the low. A 1011 mb surface low is embedded within the monsoon trough at 12N121W. Scattered moderate isolated strong convection is flaring within 180 nm over the W semicircle of the low. A trough is analyzed from 11.5N138W to 18N140W with scattered moderate isolated strong convection within 90 nm W of the trough. A surface trough extendS FROM 24N110W TO 17N110W. Isolated moderate to strong convection is observed within 120 nm of the low and trough. INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends NW off the coast of Nicaragua from 12N87W to a tropical wave at 15N96W, then turns SW to 13N105W, then continues W through an embedded 1011 mb surface low at 15N112W, then turns SW through another 1011 mb surface low embedded at 12N121W to 09N128W, then turns NW 11N138W. Isolated moderate to strong convection is noted NE of a line from 02N78W to 11N89W, and within 60 nm of line from 15N98W to 18N103W. Scattered moderate isolated strong noted within 45 nm either side of a line from 12N111W to 09N118W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A NW to SE oriented trough will meander across the Baja California Peninsula and the Gulf of California with a surface low developing intermittently along the trough near 31.5N115W. A W to E orientated ridge extends across the waters W of 112W beyond 200 nm. A moderate NW breeze is forecast across the EPAC waters W of the Baja California Peninsula through late Sat, then the pressure gradient will tighten resulting in moderate to locally fresh NW winds and 5 to 6 ft seas, to the N of 26N within 90 nm of the W coast of the Baja Peninsula, with little change through the middle of next week. Gulf of California...Moderate southerly flow forecast through early Sat, then light and variable winds expected through the middle of next week. Gulf of Tehuantepec: Fresh to locally strong nocturnal northerly flow is expected on Sat night with seas building to 9 ft downstream of the gulf waters near 14.5N95W. A stronger event is forecast on Sun and Mon nights with seas building to 10 ft. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Light W-NW flow is expected N of the monsoon trough through early Sun. Fresh southwesterly monsoonal flow is forecast through Sun with 6 to 9 ft seas in cross-equatorial swell. REMAINDER OF THE AREA... A weakening cold front extends along 32N126W to 29.5N140W. A 1021 mb surface high pressure is centered just W of the area near 29N142W, with a ridge extending E to near 17N111W. The pressure gradient will support a small area of fresh NE-E trades, and 7 to 9 ft seas, across the tropical waters from 14N to 20N W of 137W today. Otherwise moderate anticyclonic flow is expected N of the monsoon trough and W of 115W through the upcoming weekend. Fresh monsoonal flow, and 6 to 9 ft seas, is forecast S of 10N between 110W and 125W through Sat night, then the fresh trades will shift E of 110W with patches of strong SW flow near 10N108W on Mon night. $$ Nelson