000 AXPZ20 KNHC 251515 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1515 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 1200 UTC surface analysis and satellite imagery through 1500 UTC. ...TROPICAL WAVES... A tropical wave axis is near 117W south of 17N, moving west around 10 kt. Scattered moderate isolated strong convection is noted from 10N to 15N between 112W and 119W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 09N76W to 09N83W to 14N90W to 16N103W to 1011 mb low pressure near 13N114W to 11N130W. Scattered moderate isolated strong convection is noted within 180 nm south of the monsoon trough between 80W and 92W, and within 120 nm of the monsoon trough between 99W and 107W. Scattered moderate convection is occurring within 120 nm of the monsoon trough between 92W and 99W, and within 180 nm south of the monsoon trough between 121W and 130W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A weak pressure pattern across the region is resulting in gentle breezes across much of the Baja California offshore waters per overnight satellite wind data. 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 13N114W will drift northward into the offshore waters on Thu, then become absorbed within the broader monsoon circulation Fri and Sat. The SW to W monsoon flow will strengthen late in the week and through the weekend, as an area of low pressure is expected to develop along an elongated surface trough south of Mexico. There is a medium chance of tropical cyclone formation through the next five days. 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... Overnight scatterometer data revealed moderate SW to W winds off the coast of Guatemala and El Salvador, south of the monsoon trough roughly along 14N. Fresh to locally strong monsoon flow will develop in this region Thu through Sat as an area of low pressure is expected to develop off 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 19N and west of 135W per overnight satellite wind data. Locally generated wind waves, combined with residual mixed swell from Kiko, maintain 8-10 ft seas over the far western portion based on recent altimeter data. 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 northerly swell will result in seas greater than 8 ft over the waters roughly north of 25N and west of 120W through Sat. Wave heights will peak around 10-11 ft near 29N135W Thu night and Fri. A weak area of low pressure along the monsoon trough near 13N114W is producing fresh winds and 8-9 ft seas. This system will drift northward through Thu, then become absorbed within the broader monsoon circulation 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 8-12 ft. $$ Reinhart