000 AXPZ20 KNHC 252149 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1959 UTC Wed Sep 25 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 1800 UTC surface analysis and satellite imagery through 2040 UTC. ...TROPICAL WAVES... A tropical wave with an axis extending from 05N118W to 17N119W is moving west around 10 kt. Scattered moderate and isolated strong convection is noted from 10N to 15N between 115W and 123W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 11N72W to 08N79W to 15N98W to low pressure 1010 mb near 13N113.5W to 11N129W to 12N133W. Scattered moderate and isolated strong convection is seen N of 03N E of 86W and within 150 nm either side of the trough between 87W and 107W. Scattered moderate convection is evident within 180 nm S of the trough axis W of 123W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A weak pressure pattern across the region is resulting in light to gentle breezes across much of the Baja California offshore waters per satellite-derived wind data from this afternoon. Recent altimeter data shows seas are generally 4-6 ft well off the coast of Baja California Sur, as well as farther south between Manzanillo and Acapulco. A weak area of low pressure near 13.5N113W will drift northward into the offshore waters Thu, then become absorbed within a broader monsoon circulation that will develop along the S coast of Mexico Fri and Sat. The SW to W monsoon flow generated by the circulation will strengthen late in the week and through the weekend as the broad area of low pressure gradually deepens. A tropical depression is likely to form over the weekend or early next week while the system moves generally WNW at 10 to 15 mph near the southern and southwestern coasts of Mexico. Please see the latest Eastern North Pacific Tropical Weather Outlook for more information. Elsewhere, weak high pressure will develop west of the Baja peninsula tonight into Thu, resulting in moderate to occasionally fresh NW to N winds for the next several days. A weakening cold front will drop southward and cross the northern waters this weekend, accompanied by increased NW swell. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Scatterometer data from this afternoon revealed moderate to fresh SW to W winds off the coast of Guatemala and El Salvador, south of the monsoon trough or roughly S of 13N. Fresh to locally strong monsoon flow will develop in this region Thu through Sat as an area of low pressure is expected to form and gradually deepen along the southern coast of Mexico. Associated seas will build to 8-12 ft off Guatemala and El Salvador, with 8 ft seas spreading eastward toward Nicaragua and northern Costa Rica. Elsewhere, generally moderate SW flow will prevail south the monsoon trough with seas less than 8 ft. REMAINDER OF THE AREA... Moderate to fresh NE to E winds prevail north of 17N and west of 130W per overnight satellite-derived wind data. Locally generated wind waves, combined with residual mixed swell from Kiko, maintain 8 to 9 ft seas over the far western portion of the discussion area based on altimeter data from this morning. Wind speeds will diminish and seas will subside tonight into Thu as the remnants of Kiko move farther west of the area. Elsewhere, long period N swell will support seas greater than 8 ft for the waters N of 25N and west of 120W through Sat. Wave heights will peak between 10 and 11 ft near 29N135W Thu night and Fri. A weak area of low pressure along the monsoon trough near 13.5N113W is producing fresh winds and 8 to 9 ft seas. This system will drift northward through Thu, then become absorbed within a broader monsoon circulation that will form along the S coast of Mexico Fri and Sat. Expect fresh to strong winds to develop from 07N to 14N east of 110W by Fri or Fri night with seas building to between 8 and 12 ft. $$ CAM