000 AXPZ20 KNHC 030223 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2256 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 0000 UTC surface analysis and satellite imagery through 0200 UTC. ..TROPICAL WAVES... A tropical wave is approaching the NE Pacific basin extending along 87W/88W. Most of the convective activity associated with the wave is behind the wave axis affecting parts of Honduras and El Salvador. The wave will move across the remainder of Central America and SE Mexico on Thursday, reaching the Gulf of Tehuantepec by Friday. A tropical wave is south of Acapulco, and extends along 100W N of 07N. Shower activity associated with this wave has become a little better organized since yesterday. This disturbance is moving west-northwestward at 10-15 kt, and some additional development is possible before environmental conditions become less conducive for tropical cyclone formation by the end of this week. A cluster of moderate to isolated strong convection has developed ahead of the wave axis and covers from 13N-15N between 100W-102W. Scattered moderate convection is noted elsewhere from 09N-15N between 98W-103W. Fresh to strong E-SE winds are observed near the northern end of the wave axis, particularly from 14N to 16N between 97W and 101W with seas of 8 to 10 ft. The wave is forecast to reach 105W by late Thursday with fresh to strong winds and seas of 8 to 9 ft covering the waters from 15N to 18N between 102W and 105W. Then, the wave will reach 110W late Friday with winds of 20 kt or less and seas less than 8 ft. Another tropical wave extends along 111W/112W from 07N to 19N. A cluster of moderate to isolated strong convection previously located near the northern end of the wave axis has dissipated. Currently, scattered moderate convection is where the wave axis meets the monsoon trough. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from 07N78W to 11N90W to 13N100W to 12N110W to 09N120W to 08N133W. The intertropical convergence zone axis continues from 08N133W to 06N140W. Scattered moderate convection can be found from 10N to 14N between 105W and 109W, from 07N to 11N between 110W and 117W, from 07N to 10N between 120W and 130W, and from 07N to 11N W of 130W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A low level trough will meander across the Baja California Peninsula. A ridge will dominate the offshore waters W of Baja California producing gentle to locally moderate NW winds through the weekend, 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 tropical wave will move across the offshore forecast waters between the Gulf of Tehuantepec and the offshore waters of the states of Guerrero and Michoacan through late Thursday producing fresh to strong E-SE winds and seas of 8-10 ft. Please, see the Tropical Waves section for more details. In the Gulf of Tehuantepec, moderate to fresh northerly winds are expected late Friday night into early Saturday morning with the assistance of the drainage flow. 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 swirl of low clouds remains associated with this low. As the remnant low of Irwin dissipates, expect a ridge to finally build across the northern forecast waters, after an active period of tropical cyclone activity. Moderate to fresh trade winds are also expected around the southern periphery of the ridge and north of the convergence zone, mainly west of 120W. Scatterometer data indicate areas of moderate to fresh southerly winds S of the monsoon trough between 110W and 120W. Long period southerly swell, in the form of 6 to 8 ft seas, is also observed across the waters S of the monsoon trough. These seas will gradually subside through the end of the week. $$ GR