000 AXPZ20 KNHC 040947 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Tue Jul 04 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 0600 UTC surface analysis and satellite imagery through 0945 UTC. ...SPECIAL FEATURE... A tropical wave is analyzed from 08N112W to 18N112W, with a broad and disorganized 1009 mb surface low along the wave near 14N112W. This system has been moving W at 8 kt over the past 24 hours. Scattered moderate isolated strong convection is currently observed W of the low within 60 nm either side of a line from 18N112W to 12N113W. Convection remains unorganized with only intermittent banding features. Fresh southerly monsoonal flow, with seas to 8 ft primarily in southerly swell, is observed within 270 nm SE of a line 13N112W TO 11N120W. Additional development of this system is possible, and a tropical depression could form during the next 48 hours while it moves W-NW. Expect the band of fresh to locally strong monsoonal flow currently SE of the low to shift W over the next 48 hours. ...TROPICAL WAVES... A tropical wave is analyzed from 06N100W to 15N100W with scattered moderate isolated strong convection noted to the S of 13N within 240 nm E of the wave. Scattered moderate isolated strong convection is observed E of the wave and along the monsoon trough, within 210 nm either side of a line from 06N89W to 09N101W. A surface low appears to be developing within this convection near 07N94W. Environmental conditions are favorable for gradual development of this low as the parent area of disturbed weather moves westward. Please refer to the NHC Tropical Weather Outlook for the East Pacific at hurricanes.gov for more information. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends W off the Pacific coast of Costa Rica at 09N83W to 08N95W, then turns NW to 10N105W where it loses identity. Scatterometer data indicates that the monsoon trough resumes again near 15N108W, and extends SW through an embedded low pres at 14.5N112W to 09N137W where it loses identity again. Scattered moderate isolated strong convection is observed within 60 nm either side of a line from 07N77W to 03N79W, elsewhere within 210 nm of lines from 06N87W to 11N103W and from 12N110W to 08N130W to 10N140W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A NW to SE orientated ridge axis extends into the offshore waters along 23N116W to 19N105W. Gentle to locally moderate NW flow, with 3 to 5 ft seas, are forecast W of the Baja Penisula through Wed morning. The pressure gradient will then tighten, with a moderate NW breeze W of Baja, except increasing to a fresh breeze N of 26.5N within 60 nm of the coast during the late afternoons. Moderate to fresh cyclonic flow is expected across the waters S of 19N between 101W and 115W through Wed morning in association with a surface low S of the offshore waters. Gulf of Tehuantepec...Strong N-NE drainage flow will continue across the gulf waters to along 14N between 95W and 97W through late morning. Strong N flow will develop again each night this week. Model guidance is suggesting significant gap events will occur late Fri and Sat nights, with seas building to 10 ft downstream of the gulf waters near 15N95.5W. Gulf of California...A surface low will develop intermittently over the far northern gulf waters with a thermal trough meandering S from the low across the Baja Peninsula and gulf waters this week. A light to gentle, mostly southerly, breeze is expected this week. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo...Moderate to fresh nocturnal NE-E flow expected this week. Guidance is hinting at a strong NE pulse on Sat evening. Gentle to moderate southerly winds are forecast s of the monsoon trough which will extend E to W along roughly 09N. Long period SW swell in the form of 7 to 9 ft seas, will reach along the equator on Wed, and reach along 08N on Thu night before beginning to subside. REMAINDER OF THE AREA... See special features and tropical wave paragraphs above. A trough will develop from 12N134W to 29N130W today, drift W on Wed and Thu passing 140W on Fri all the while accompanied by a gentle NE to E to SE wind shift. NW to SE orientated ridge will then rebuild across the area. Fresh NE winds are expected from 11N to 23N W of 134W today with small pockets of seas building briefly to 8 ft. Long period southerly swell, in the form of 7-9 ft seas will cross the equator between 93W and 115W on Wed night, and reach along 10N on Fri. $$ Nelson