000 AXPZ20 KNHC 281559 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1404 UTC Wed Nov 28 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 1200 UTC surface analysis and satellite imagery through 1445 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 08N83W to 06N92W to the low pressure near 13N106W to 07N126W. The ITCZ continues from 07N126W to 06N140W. Scattered moderate convection is observed within 60 nm either side of the convergence axis west of 110W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... The gale warning for the Gulf of Tehuantepec has been allowed to expire at 12Z. The pressure gradient between strong high pressure along the E slopes of the Sierra Madre Oriental and lower pressure south of Tehuantepec has begin to weaken, and this trend should accelerate. As a result, winds will rapidly diminish today and tonight as high pressure over eastern Mexico continues to weaken and begins to shift E. Seas in the Gulf region will subside to less than 8 ft by late tonight. A 1007 mb low pressure system is embedded within the monsoon trough near 14N107W. Scattered moderate convection is taking place within 360 nm of the center in the E semicircle. Upper- level winds have become less conducive for development, and tropical cyclone formation is becoming less likely. However, shower activity associated with the disturbance is still forecast to move northeastward toward southwestern Mexico today through Thursday, bringing locally heavy rainfall to portions of the Mexican states of Guerrero, Michoacan, Colima and Jalisco. These rains could result in life-threatening flash floods and mudslides. Refer to the latest NHC Tropical Weather Outlook under AWIPS/WMO headers MIATWOEP/ABNT20 KNHC for more information on this system. Gulf of California: Winds across the north and central Gulf of California will be light and variable, with seas of 1 to 2 ft. Winds are expected to increase to between 20 and 30 kt with seas of 5 to 7 ft across the northern Gulf Thu night and Fri as a cold front sweeps across the area. Long period NW swell of 8 to 11 ft is reaching the coast of Baja California Norte. The swell will reach the southern coast of Baja California and the Revillagigedo Islands tonight and cause seas to build to between 8 and 12 ft in the open waters W of the Peninsula. The swell will cause seas to build to 8 ft or above as far east as 105W by late Thu between Clarion Island and Cabo Corrientes, mixing with southerly swell.A reinforcing surge of swell will maintain seas W of Baja Fri night and Sat. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo: Fresh NE winds will pulse across the Gulf each night through Sun night. Elsewhere, the monsoon trough will remain between 08N and 11N during the rest of the week, with gentle to moderate winds on either side of the trough, with 5 to 7 ft seas expected. REMAINDER OF THE AREA... A cold front crosses the far NW portion of the discussion area from 32N133W to 28N140W. The front will weaken today as it heads E, but a reinforcing surge of cold air will push the front southward to near 25N west of 125W through Thu, with the eastern part of the front moving into northern Baja California Thu night. Large long period NW swell associated with the front will dominate most of the region west of 120W through Thu, reaching 14 to 16 ft north of 28N. This swell will continue to move eastward and overspread almost all of the waters W of 100W by Fri morning and the leading edge of 8 ft seas will make it as far E as 95W by Sat morning, but the swell will begin to decay and allow seas W of 130w to fall below 8 ft by this weekend. $$ CAM