000 AXPZ20 KNHC 271605 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Sun Oct 27 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 1200 UTC surface analysis and satellite imagery through 1545 UTC. ...TROPICAL WAVES... A tropical wave has its axis along 87W N of 10N. It is moving westward near 10 kt. This wave extends northward across northwestern Nicaragua, western Honduras and continues to northwestern Caribbean Sea. The wave, in conjunction with a well-defined upper-level low located just north of Honduras is producing isolated 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 106W/107W from 05N to 18N. It is moving westward at about 10 kt. Scattered showers and isolated thunderstorms are within 180 nm to the east of the axis from along the monsoon trough north to 14N. TPW animation imagery reveals ample deep moisture east of this wave extending northward to just south of the coast of Mexico between Puerto Angel and Manzanillo. Scattered showers and thunderstorms are seen from 13N to 16N between 96W and 101W. Similar activity is likely to form elsewhere within this area of deep moisture today through Mon. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from northwestern Colombia near 10N75W, and continues westward across northern Costa Rica to near the Gulf of Papagayo near 11N86W, then to low pressure of 1009 mb near 11N101W, to 10N112W to low pressure of 1009 mb near 11N128W, to 10N130W and to 10N140W where it transitions to the ITCZ well west of the discussion area. Scattered moderate to strong convection is seen within 180 nm south of the trough between 96W and 99W. Scattered moderate convection is within 120 nm north of the trough between 93W and 96W, and also within 120 nm south of the trough between 107W and 110W. Similar activity is within 60 nm south of the trough between 130W and 138W. Scattered moderate convection is occurring within 120 nm to the west of the Colombian coast from 04N to 08N within 120 nm W of the coast of Colombia. This convection developed over inland areas on Sat near the axis of an upper level trough prior to propagating offshore with the low level easterly flow. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Gulf of Tehuantepec: The recent gale warning was allowed to expire early this morning. The tight gradient that induced the recent gale force northerly winds 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 with these are now maxing out to 8 ft. The strong winds will diminish to 20 kt or less by late this afternoon, and the wave heights are forecast to lower to less than 8 ft at that time. Looking ahead, according to model guidance another gale force northerly gap wind event may possibly get under way in the Gulf of Tehuantepec late Thu night into Fri. Stay tuned to future marine forecasts and discussions that will describe this next gap wind event. Gulf of California/Sea of Cortez: Strong south to southwest winds have developed over the far 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 frontal trough and increase to 20-30 kt beginning late tonight and into Mon morning, with fresh to strong winds spreading southward to near 26N by late Mon morning or early afternoon. These winds are then forecast to diminish to 20 kt or less on Mon night. Looking ahead, a tight pressure gradient will develop across the region again by Wed with strong to minimal gale force northwest winds once again developing 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 northwest to north 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 Wed night 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 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 8-11 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 15N and west of 130W on Tue, gradually decaying thereafter. A couple of weak lows are embedded within the monsoon trough; the first is near 11N101W 1009 mb and the second is positioned at 11N118W 1009 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. Only isolated showers and thunderstorms are seen near these lows. Global model guidance suggests that the eastern low is forecast to move in a westward to west-northwestward direction well into the upcoming week. $$ Aguirre