000 AXPZ20 KNHC 280231 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 022 UTC Mon Oct 28 2019 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. ...TROPICAL WAVES... A tropical wave's axis is located along 86W and north of 12N, moving W at 5-10 kt. The wave, in conjunction with a well- defined upper-level low located just north of Honduras is producing scattered showers and thunderstorms just inland the coast of Nicaragua and possibly between the coast of Nicaragua and 10N. With the upper-level low being the more dominant feature, this wave is expected to weaken as it tracks westward across the rest of northern Central America through Mon. A tropical wave has its axis along 107W from 04N-15N. The wave is moving westward at 5-10 kt. Scattered showers are within 180 nm to the east of the axis from 09N-12N. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 08N82W to 09N86W to 1007 mb low near 12N100W to 1010 mb low near 12N117W to 1007 mb low near 11N124W to 1006 mb low near 12N133W to beyond 11N140W. Scattered moderate convection is noted within 120 nm either side of the trough between 91W-107W and within 75 nm either side of the trough between 120W-135W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Gulf of Tehuantepec: The tight gradient across the Gulf has slackened allowing for the winds to diminish to the strong range within 30 nm either side of a line from 16N95W to 14N95.5W. Wave heights in this area will range between 4-6 ft. The strong winds will diminish to 20 kt or less by this evening, and the wave heights are forecast to lower to less than 8 ft. Looking ahead, model guidance continues to suggest that another gale-force northerly gap wind event may develop in the Gulf of Tehuantepec by late Thu into Fri. Stay tuned to future marine forecasts and discussions that will describe this event. Gulf of California/Sea of Cortez: Moderate to fresh south to southwest winds have developed over the northern section of the Gulf of California ahead of an an approaching frontal trough, with wave heights less than 8 ft. Winds will veer to the northwest to north with passage of the trough and increase to 20-25 kt beginning overnight into Mon morning, with fresh to strong winds spreading southward to near 27N by late Mon morning or early afternoon. These winds are then forecast to diminish to 20 kt or less by late Mon. Looking ahead, a tight pressure gradient will develop across the region again by Wed with strong to minimal gale force northwest winds expected to develop over the northern Gulf in the wake of a strong cold front that will sweep southward across the southwestern U.S. and the far northwest section of Mexico. Fresh to strong northerly winds are forecast to spread across the entire Gulf by Thu, likely to continue into early Fri before diminishing to mainly fresh speeds. Otherwise, relatively weak high pressure to the west of Baja California will continue to support light to gentle northwest to north winds through the middle of the week along with wave heights mainly in the 4-7 ft range. By late Wed into early Thu, the fresh to strong winds described in the Gulf of California section are forecast to seep through the Baja California Norte passages and across the waters north of Punta Eugenia. These winds will then diminish by Thu night. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Light to gentle winds are expected across the offshore waters of Guatemala and El Salvador. Gentle to moderate south to southwest monsoonal flow, occasionally pulsing to moderate to fresh speeds will continue across the offshore forecast waters of Costa Rica, Panama, Colombia and Ecuador through the week. Wave heights are expected to be in the 4-7 ft range. REMAINDER OF THE AREA... A speed convergence line is noted along and just north of 30N, with fresh to strong northeast winds north of it. A set of fresh northerly swell behind this boundary is propagating southward and will build wave heights to the the 8-10 ft range north of 25N and west of about 120W by Mon. The edge of the 8 ft or greater wave heights is forecast to propagate southward reaching the waters north of 17N and west of 135W on Tue, gradually decaying thereafter. A few weak lows are embedded within the monsoon trough; the first is near 11N101W 1009 mb, the second is positioned at 12N124W 1011 mb, the third is located near 11N133W 1010 mb. Atmospheric instability associated with these lows has decreased during the past 24 hours allowing for the earlier observed deep convection that was occurring near the monsoon trough to diminish. At this time, scattered showers and thunderstorms are noted near these lows, mainly with the one along 101W. Global model guidance suggests that the eastern low is forecast to move in a westward to west-northwestward direction well into the upcoming week. $$ ERA