000 AXPZ20 KNHC 051548 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC SUN JUN 05 2016 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 1545 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough was analyzed from 12N101W to 10N106W to an embedded 1007 mb low pres near 10.5N120W, with the monsoon trough continuing sw to 06N130W where scatterometer winds indicate an ITCZ forms, and continues w to beyond 07N140W. Scattered moderate isolated strong convection is observed n of 07N between 84W and 101W. Scattered moderate isolated strong convection is noted along the monsoon trough within 120 nm either side of a line from 11N102W to 08N111W to 11N115W. ...DISCUSSION... N of 15N e of 120W: A nnw to sse surface trough is expected to develop each afternoon during peak heating over the Baja California Peninsula through midweek, with a 1002 mb surface low developing over the northern Gulf of California on Mon and persisting for a few days. A broad ridge extends e across the open Pacific waters with the associated pressure gradient expected to maintain moderate to fresh nw flow across the open pacific waters n of the ridge axis, except increasing briefly to strong along the Pacific coast of the Baja Peninsula to the n of 25N through this evening. Guidance is persistent with fresh to locally strong southerly flow developing across the southern Gulf of California on Mon night. S of 15N e of 120W: A broad and elongated area of low pressure continues embedded within the monsoon trough, and is analyzed as a 1007 mb surface low at 10.5N120W. Recent scatterometer winds indicate that the pressure gradient has relaxed some, with n to ne 15 to 20 kt winds within 300 nm n of the center. Associated convection has been fluctuating in both coverage and intensity. Currently, scattered moderate isolated strong convection is observed well sw of the estimated low level center, roughly within 30 nm either side of a line from 10N120W to 11N122W. a very recent burst of convection is observed ne of the center near 11N119.5W. Although sea surface temperatures are warm, atmospheric conditions are becoming less favorable as the low moves s of an upper anticyclone and experiences increasing northeasterly wind shear. The forecast is for the low to reach near 10.5N123W early Mon, and then weaken to an open trough on Mon night. A tropical depression has formed n of the area near the Yucatan Peninsula and is trailing a broad low level trough sw across Mexico into the area from 16N98W to 13N102W. Moderate to fresh southwesterly flow is observed to the w of 85W and south of the monsoon trough with 4-7 ft seas in southerly swell. A surface low is developing in the vicinity of the surface trough near 11N100W with a band of convection rapidly developing over the w semicircle of the low. Additionally, a small cluster is also developing e of the estimated center near 11N98.5W. This low is expected to track ne moving inland Mexico near the Isthmus of Tehuantepec on Tue night, and then passing ne across the Yucatan Peninsula on Wed but still trailing a trough sw across the East Pacific waters. As previously mentioned, considerable convection is observed across the Pacific waters s of Central America and extreme Se Mexico. The southerly flow will advect this convection inland with the possibility of localized flooding, especially in areas of elevated terrain where landslides may occur. W of 120W: A 1018 mb surface high is analyzed at 25N131W. Except as previously mentioned in association with the surface low at 10.5N120W, moderate to fresh ne trades dominate the East Pacific between 20N and the ITCZ/monsoon trough, and are accompanied by 4-6 ft seas. A weak cold front will move into the far nw waters near 30N140W early Mon. Latest guidance is a little more aggressive, and suggests fresh to strong southerly flow will preceded the front this afternoon into tonight, then diminish to a moderate s-sw-w wind shift along the front extending from 32N138w to 26N140W late Mon. The front is expected to stall from 32N134W to 24N140W on Tue. $$ Nelson