000 AXPZ20 KNHC 021517 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1500 UTC Wed Aug 2 2017 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 1500 UTC. ..TROPICAL WAVES... A tropical wave is approaching the NE Pacific basin extending from the NW Caribbean Sea to across eastern Honduras and Nicaragua to near the Costa Rica/Panama border moving at around 10 to 15 kt. The majority of the associated convection is lagging behind the wave and will move across Central America through the end of the week, with the wave reaching the Gulf of Tehuantepec by late Friday. A tropical wave extends from the Mexican coast near 16N97W to 1010 mb low pressure near 12N98W to 06N99W moving WNW around 10 kt. Scattered moderate convection is within 180 nm in the SW semicircle of the low and also between 120 nm and 300 nm in the NE semicircle. Fresh to strong winds and building seas of 7 to 9 ft will accompany the low on the NE side across the offshore waters through Thursday night, then will diminish as the low weakens thereafter. A tropical wave extends from 17N106W to 07N104W moving W around 10 kt. This wave is likely helping to enhance convection just SW of Cabo Corrientes with scattered moderate to strong from 17N to 20N between 104W and 109W. A tropical wave extends from 17N116W to 07N113W moving W at around 5 to 10 kt. Associated convection remains limited with this wave. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from 10N74W to 09N81W to low pressure near 12N98W to 08N120W to 09N130W. The intertropical convergence zone axis extends from 09N130W to 06N140W. Scattered moderate and isolated strong convection is within an area bounded by 08N140W to 10N124W to 10N115W to 05N125W to 06N130W to 04N140W to 08N140W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A low level trough will meander across the Baja California Peninsula while a NW to SE oriented ridge extends just W of the offshore waters. A gentle to locally moderate NW breeze is expected through the weekend W of the Baja California Peninsula, with combined seas of 4 to 6 ft primarily in long period S swell. Gentle southerly flow will persist across the Gulf of California. A surface low near 12N98W is forecast to move WNW at 10 kt with fresh to locally strong E-SE winds, and 7 to 9 ft seas, extending out as far as 240 to 300 nm NE of the low, and across the offshore waters through Thursday. Thereafter, associated winds should diminish to a moderate to locally fresh breeze as the low passes S of Cabo San Lucas on Friday and Saturday. In the Gulf of Tehuantepec, fresh northerly drainage winds expected late Friday night into early Saturday. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... In the Gulf of Papagayo, moderate to fresh nocturnal offshore winds are expected tonight and again on Thursday night with seas building to 6 ft. Otherwise, moderate southerly winds are expected S of the monsoon trough axis and gentle and variable winds N of the monsoon trough. Long period southerly swell will continue to decay with seas around 4 to 6 ft subsiding to 3 to 5 ft by the end of the week. Seas will build late in the weekend as a new pulse of southerly swell arrives. REMAINDER OF THE AREA... The remnant low of Irwin is located near 28N131.5W and is expected to weaken to an open trough in about 24 hours. A ridge will rebuild from 31N140W to 21N111W on Friday. Long period southerly swell, in the form of 6 to 8 ft seas, is observed across the waters S of the monsoon trough. These seas will gradually subside through the end of the week. $$ Lewitsky