000 AXPZ20 KNHC 242123 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1927 UTC Sat Jun 24 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 1800 UTC surface analysis and satellite imagery through 2100 UTC. ...SPECIAL FEATURES... A low pressure is embedded within the monsoon trough near 13.5N98.5W or a couple of hundred miles south-southeast of Acapulco, Mexico. Active convection is noted over this area from 11N to 16N between 93W and 101W. Overnight scatterometer pass depicted a well defined center of circulation with fresh winds noted over the north quadrant of the low. This system continues to become better organized, and a tropical depression appears to be forming. If this development trend continues, then advisories will be initiated this evening. The low is expected to move west- northwestward at 10 kt parallel to the coast of Mexico during the next couple of days, bringing heavy rains to the Mexican states of Oaxaca and Guerrero. Interests along the southwestern coast of Mexico should monitor the progress of this system. Please, refer to the latest Tropical Weather Outlook. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 10N85W to a low pressure near 13.5N98.5W to 10N102W to 09N112W to 08N120W to 09N130W. The ITCZ axis continues from 09N130W to beyond 08N140W. Scattered moderate to isolated strong convection is from 07N to 11N between 97W and 105W, and from 07N to 10N between 118W and 124W. Scattered moderate convection is from 07N to 10N W of 133W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... See Special Features for more information on the low pressure located a couple of hundred miles south-southeast of Acapulco, Mexico. Elsewhere, high pressure of 1017 mb centered near 25N128W extends a ridge across the offshore forecast waters. Gentle to moderate winds are noted west of the Baja California peninsula per scatterometer data, with light to gentle winds off the coast of southwest Mexico, and across the Gulf of California. Seas are in the 5-6 ft range off the coast of the Baja California Peninsula, 1-2 ft over the Gulf of California, and 5-6 ft elsewhere, with the exception of seas to 8 ft within about 120 nm NE qudrant of the aforementioned low pressure. Winds will freshen off the coast of Baja California Norte later this weekend as high pressure west of the area slightly strengthens. Mainly gentle to moderate southerly winds are expected across the Gulf of California during the remainder of the weekend with seas generally under 4 ft. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gentle to moderate southwest to west winds are expected across most of the region during the forecast period, with the exception of mainly south winds between Ecuador and the Galapagos Islands. Additional pulses of long period southwest swell will continue to impact the region, but seas will remain generally below 6 ft the remainder of the weekend. Cross equatorial long period southerly swell are expected to reach the waters between Ecuador and the Galapagos Islands Monday night into Tuesday, building seas up to 9 ft, except in the lee of the Galapagos Islands. REMAINDER OF THE AREA... A surface trough extends from a 1012 mb low pres located north of area near 33N130W to 24N137W. Moderate to fresh northerly winds are on the west side of the low. East of the trough, a 1017 mb high pressure is centered near 25N128W, and extends a ridge across the waters north of the convergence zone, producing mainly light and variable winds N of 20N W of 120W, and gentle to moderate winds between the convergence zone and 20N. Altimeter passes continue to indicate seas of 8 to 11 ft, in northerly swell, affecting the waters N of 20N W of 120W. Seas will gradually subside from east to west on Sunday. The low pressure located north of area and associated trough will persist on Sunday. The low will open up into a trough on Monday while weakening. As a result, the ridge will build back across the region Monday and Tuesday. $$ GR