000 AXPZ20 KNHC 061022 CCA TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Fri Oct 6 2017 ...Corrected to add gale warning section 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 0900 UTC. ...GALE WARNING... Gale force winds developed in the offshore zone of Nicaragua and NW Costa Rica as shown in the latest scatterometer data. Seas range between 15 and 18 feet in that region. Winds will reach a peak of 40 kt later this morning and then will gradually diminish to below gale-force by early Saturday morning. ..INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 12N87W to low pres 1007 mb centered near 16N105W to low pres 1010 mb centered near 12N115W to 10N128W to low pres 1009 mb centered near 11N135W to 10N140W. Scattered moderate convection is from 08N to 13N between 108W and 119W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... The broad cyclonic circulation constituting a Central American Gyre is causing an atypical NW to N gap wind event over the Gulf of Tehuantepec. Gap winds in Tehuantepec will gradually diminish reaching below advisory levels by early Sunday morning due to weakening of the Central American Gyre. The gradient between low pressure along the Baja California Peninsula and high pressure west of 120W will support gentle to moderate N to NW winds through early Sunday. Seas during that period will range between 5 to 7 feet. Otherwise, NW swell will support seas of 8 to 10 ft N of 25N and W of Baja through Tuesday morning. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Numerous strong convection and thunderstorms are in the offshore zone of Guatemala and El Salvador associated with the large monsoonal circulation of the Central American Gyre. To the east- southeast of this area of convection, in the offshore zone of Nicaragua and NW Costa Rica, latest scatterometer data show gale force winds developed with seas ranging between 15 and 18 feet. Winds will reach a peak of 40 kt later this morning and then will gradually diminish to below gale-force by early Saturday morning. Long period cross equatorial SW swell is generating sea heights ranging from 8 to 11 feet in the waters from Panama to Costa Rica forecast, which will start subsiding tonight. The large seas will create dangerous breaking surf along the coast in these areas. The monsoonal flow will continue to support copious rain between northern Costa Rica and Guatemala into the weekend. This extremely heavy rainfall will produce life threatening flash floods and mudslides. REMAINDER OF THE AREA... Gentle to moderate winds prevail north of the monsoon trough to 21N and west of 123W. A weak cold front over NW forecast waters extending from 30N138W to 28N140W supports seas of 8 to 9 ft west of the boundary. The front is forecast to dissipate tonight, however seas are forecast to subside by late Saturday morning. Otherwise, long period SW swell is maintaining seas above 8 ft over all of the discussion area from 06N to 18N between 79W and 117W. The long period swell will gradually decay and seas in this area are expected to subside below 8 ft by Sunday morning. $$ Ramos