000 AXPZ20 KNHC 220231 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 203 UTC Sat Oct 22 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 0000 UTC surface analysis and satellite imagery through 0200 UTC. ...SPECIAL FEATURES... Numerous showers and thunderstorms located a few hundred miles south-southwest of the Gulf of Tehuantepec are associated with a broad area of low pressure located near 11N97.5W. Satellite imagery indicates a cluster of moderate to strong convection within about 150 nm NW quadrant of low. Scattered moderate is elsewhere from 09N to 14N between 100W and 104W. Environmental conditions are expected to be conducive for development of this disturbance over the next few days, and a tropical depression will likely form early next week while the system moves toward the west-northwest at about 10 kt. A gale warning remains in effect for the Gulf of Tehuantepec. The latest marine guidance suggests that the current minimal gale force winds will increase to 30 to 40 kt tonight, then diminish to 30 to 35 kt on Sat and continue into the early morning hours on Sun before diminishing below gale force by late sun morning. Minimal gale force conditions are expected to develop again late Mon and continue through Tue night. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 1008 mb low pres near 11N97.5W to 12N105W to 1007 mb low pres near 13N116W to 10N124W to low pres near 11N130W to 13N140W. Scattered moderate isolated strong convection is noted from 08N to 11.5N between 120W AND 129W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... See special features for Gulf of Tehuantepec. A sub-tropical ridge axis extends from NW to SE across the offshore waters of Baja California. Light to gentle NW flow with combined seas of 5 to 7 ft are expected through Sat night. Seas are forecast to then build to 7 to 9 ft across the waters N of 27N W of 118W early Sun morning through Sun evening. Gentle to moderate NW winds are blowing across the Gulf of California, and are forecast to become light and variable on Sat, then light southerly flow is expected across the entire gulf waters late Sat. Light and variable winds are expected elsewhere within 250 nm of the Mexican coast N of the Gulf of Tehuantepec through Sat, except moderate E to SE winds are forecast beyond 200 nm on Sun and Mon as a low pres likely develops just south of the forecast zones. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gentle to moderate S to SW winds are noted per scatterometer data S of 06N, while gentle to moderate W to NW winds are N of 06N. Combined seas of 4 to 7 ft, primarily in long-period SW swell is expected across the offshore waters for the next 3 to 5 days. REMAINDER OF THE AREA... A ridge dominates most of the north waters N of 15N W of 115W. The pres gradient between the ridge and lower pres in the vicinity of the monsoon trough is resulting in an area of moderate to fresh winds between 14N and 18N W of 135W based on the latest Ascat pass. Seas in this area are near 8 ft according to an altimeter pass. A cold front is expected to approach 30N140W tonight while gradually dissipating through late Saturday. A new set of long period NW swell follows the front. This swell event will propagate SE across the NW waters Sat and Sun, reaching the waters W of Baja on Sun. Another cold front will be near 30N140W on Monday and will be reinforcing by a second cold front reaching the same area on Tue. The merging cold front is forecast to extend from 30N135W to beyond 27N140W by late Tue. $$ GR