000 AXPZ20 KNHC 050957 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 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 0600 UTC surface analysis and satellite imagery through 0830 UTC. ...SPECIAL FEATURE... An elongated area of low pressure continues to shift slowly westward along the monsoon trough, located near 11N120W, with an estimated pressure of 1007 mb. Showers and thunderstorms have diminished over the past several hours since an earlier afternoon burst of convection. Recent scatterometer data across the area suggests that winds continue at 20-25 kt within 180 nm to the northwest of the center, with seas to 8 ft. The system remains elongated northeast to southwest with at least two cyclonic circulations appearing intermittently over a large area. Atmospheric conditions remain favorable for increased organization and thus this system has a medium chance of tropical cyclone development over the next couple of days. Please refer to the Tropical Weather Outlook under AWIPS/WMO headers TWOEP/ABPZ20 KNHC for additional details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough stretches from 13N97.5W to 14N102W to low pressure near 11N120W 1007 mb to 07N131W, where it transitions to ITCZ, continuing on to beyond 08N140W. Scattered to locally numerous moderate to strong convection is noted north of 07N to the coastline between 86W and 100.5W. Scattered moderate to strong convection is noted from 08N to the monsoon trough between 100.5W and 115W. ...DISCUSSION... North of 15N and east of 120W: A weak surface ridge extends from 1018 mb high pres 24.5N133W to 22N118W. This is maintaining generally light to gentle breezes across the region, except near the west coast of Baja California, where the afternoon seabreeze continues to produce fresh NW winds beyond sunset. Seas are 4 to 6 ft in open Pacific waters and 2 to 4 ft in the Gulf of California. The northwest flow will increase each of the next two afternoon through late evenings along the coastal waters of Baja California due to a slight increase in the pressure gradient between the high pressure west of the area and a deepening trough reaching from the northern Gulf of California to Socorro Island by late Monday. Winds along portions of the peninsula will increase to20- 25 kt with seas building to 6-7 ft during this time, while winds elsewhere reach around 20 kt. Looking ahead to Tuesday, this pattern will also allow south to southeast winds to develop inside the Gulf of California with seas building to 4 to 6 ft across southern portions. South of 15N and east of 120W: An elongated cyclonic circulation in the lower atmosphere has developed during the past 48 hours from near 10N105W extending northeastward across Central America and into the northwest Caribbean, referred to regionally as a "temporal". Abundant tropical moisture has become entrained within this low level circulation, which is yielding clusters of scattered to numerous moderate to strong thunderstorms across large portions of this broad area. The strongest thunderstorms are presently occurring from 07N to the Pacific coastlines between central Nicaragua and Acapulco, Mexico. Fresh southwesterly winds have developed south of the monsoon trough between 110W and 100W and are producing another area of scattered strong thunderstorms there. Persistent southwesterly low level flow will continue to transport abundant tropical moisture across this area and into Central America today through Tuesday, yielding high chances for rain from Nicaragua to the Gulf of Tehuantepec region of Mexico and spreading well inland. Some of these areas could see intermittent heavy to torrential rainfall leading to flash flooding and landslides during this period. Across the marine area, the southwest winds are expected to freshen south of the monsoon trough between 95W and 105W through Monday, where seas will build 6-8 ft by this evening and possibly 7-9 ft by Monday. Global models suggest that a low pressure system could quickly develop along the monsoon trough in this area and move northeastward towards the Gulf of Tehuantepec, with the potential for winds to peak near 30 kt late Monday. Elsewhere from the equator to 32N east of 140W: A 1018 mb surface high is analyzed at 24.5N133W. Except as previously mentioned in association with the surface low at 11N120W...moderate ne trades cover the eastern Pacific between 20N and the ITCZ/monsoon trough and are accompanied by 4-6 ft seas. The high will meander near its current position through Tuesday and maintain moderate northeast trades south of 20N. A weak cold front will move into the far nw waters near 30N140W early Monday, and stall from 32N128W to 22N140W on Wednesday night. $$ Stripling