000 AXPZ20 KNHC 212205 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 UTC Wed Nov 21 2018 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 2145 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: Presently strong to near gale force north to northeast are across the Gulf. As the pressure gradient continues to tighten over southeastern Mexico tonight, these winds will increase to minimal gale force. Model guidance indicates that this upcoming pulse of minimal gale force winds will be short-lived as they are forecast to diminish back to near gale force early on Thu and continue at those speeds through late on Thu before diminishing to fresh winds on Fri afternoon and to light and variable winds by Fri evening ,with little change through the upcoming weekend. The next gap wind event across the Tehuantepec region is forecast on Mon. Model guidance suggest that these winds will reach strong to near gale force late on Mon of next week and into early on Tue. Seas will build to 11-12 ft during the gale force events. Please refer to the East Pacific High Seas Forecast under AWIPS/WMO headers HSFEP2/FZPN03 KNHC for more details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from 09N78W to 08N93W to 06N104W. The ITCZ axis continues from 06N104W to 07N120W to 09N132W to 09N140W. Scattered moderate convection is within 120 NM n and 60 nm s of the ITCZ axis between 113W and 118W. Similar convection is within 30 nm of a line from 08N122W to 10N125W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... See Special Features section for Gulf of Tehuantepec Gale Warning information. Gulf of California: In the northern Gulf, light and variable winds will persist through tonight. Gentle to moderate NW-N winds will follow a weak cold front moving across the area on Thu. In the southern Gulf, gentle to moderate NW to N winds will increase to moderate to fresh late Thu through Fri night as a ridge builds across southern Baja California into the entrance of the Gulf of California. Light and variable winds are noted across the offshore waters to the west of the Baja California Peninsula are due to the presence of a 1022 mb high pressure located near 27N115W. A weakening cold front is forecast to approach and move across the area on Thu. High pressure in the wake of the front will build eastward bringing increasing winds and building seas across the waters mainly to the north of of 29N by Fri night, and then to the north of 26N by early on Sat. Wave model guidance suggests NW winds of 20 to 25 kt with building seas of 6 to 9 ft with NW swell. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo: Fresh to locally strong NE winds with seas building briefly to 8 ft are expected during the overnight and early morning hours through Fri, diminishing thereafter. The monsoon trough will extend roughly along 08N/09N during the next few days with gentle to moderate NE winds N of the trough, and moderate to fresh SW winds S of the trough. Seas will be in the range of 4 to 6 ft mainly in mixed long-period SW and NW swell. REMAINDER OF THE AREA... A cold front extends from near 32N123W to 26N128W and is dissipating to near 24N135W. Seas of 8-12 ft in NW swell are following in behind the front, except higher seas of 10 to 13 ft to the north of 29N. The front will continue southeastward across the northern forecast waters reaching a position from 32N115W to 28N120W to 24N125W by Thu morning while gradually weakening and dissipating by Fri morning. Swell behind the front will propagate across the waters north of about 20N and to the west of a line from 32N115W to 20N120W to another line from 32N125W to 24N140W by Fri morning. The pressure gradient between high pressure building eastward across the forecast area and lower pressure in the vicinity of the ITCZ will result in fresh to strong trade winds of 20 to 30 kt and seas of 8 to 11 ft mainly over the waters from 11N to 21N W OF 130W, and from 16N to 20N between 122W and 130W by Thu morning. Similar marine conditions are expected by Fri morning. $$ GR