758 AXPZ20 KNHC 020919 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 731 UTC Tue Oct 2 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 0600 UTC surface analysis and satellite imagery through 0900 UTC. ...SPECIAL FEATURES... Rosa has been downgraded to a Tropical Depression at 02/0900 UTC as it approaches the coast of Baja California Norte. At this time, Rosa is centered near 29.3N 114.9W or about 130 nm N of Punta Eugenia, Mexico moving toward the NNE at 9 kt. Estimated minimum central pressure is 1003 mb. Maximum sustained wind speed is 30 kt with gusts to 40 kt. Rosa is completely exposed and continues to lack deep convection near the center. Doppler Radar indicates that most of the convective activity associated with this tropical cyclone is now over the far northern Gulf of California/NW Mexico and southern Arizona in United States. On the forecast track, the center of Rosa will move across the Baja California peninsula and into the northern Gulf of California this morning. Rosa's remnants are then expected to move across the Desert Southwest by tonight. Swells generated by Rosa will affect portions of the coasts of southwestern Mexico, most of the west coast of the Baja California peninsula, and southern California through today. These swells are likely to cause life- threatening surf and rip current conditions. See latest NHC forecast/advisory under AWIPS/WMO headers MIATCMEP5/WTPZ25 KNHC for more details. Sergio was upgraded to hurricane status at 02/0300 UTC, and latest satellite imagery suggests that the hurricane is rapidly intensifying. At 02/0900 UTC, Sergio is centered near 10.7N 113.2W or about 755 nm SSW of the southern tip of Baja California, moving W at 12 kt. Estimated minimum central pressure is 986 mb. Maximum sustained wind speed has increased to 75 kt with gusts to 90 kt. Additional strengthening is expected during the next couple of days, and Sergio is forecast to be near major hurricane strength by Wednesday or Wednesday night. Numerous moderate to strong convection is noted within 90 nm of center. Numerous moderate to isolated strong convection is seen elsewhere within 150 nm of center. See latest NHC forecast/advisory under AWIPS/WMO headers MIATCPEP1/WTPZ31 KNHC for more details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from northern Colombia, across parts of Panama and Costa Rica to 09N84W to 10N90W to 12N105W. Another segment of the monsoon trough reaches from 15N120W to beyond 10N140W. Scattered moderate to isolated strong convection is within 150 nm S of the trough between 80W and 85W, and from 07N to 15N between 93W and 104W. Scattered moderate convection is from 12N to 15N between 121W and 128W, and from 10N to 12N between 130W and 135W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... See Special Features above for information on T.D. Rosa and Hurricane Sergio. Swell associated with Rosa is still affecting the offshore forecast waters W of Baja California, particularly N of 25N E of 118W, with seas of 8 to 11 ft. These seas will subside to less than 8 ft later today. Farther south, swell generated by Sergio, with seas to around 8 ft, is reaching the coast of Colima and Guerrero based on a recent altimeter pass. This swell event is also reaching the Revillagigedo Islands, and could produce dangerous surf conditions in the coastal areas during the next few days. In the Gulf of California, the most recent scatterometer pass confirmed the presence of fresh to strong southerly winds across parts of the north and central Gulf, mainly N of 27N. Winds and seas will diminish today as Rosa continues to weaken into a remnant low inland. In the Gulf of Tehuantepec, pulsing winds of 20 to 30 kt are expected during the overnight and early morning hours through at least early Wed morning. Seas are forecast to build to 9 or 10 ft with the strongest winds. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... The monsoon trough will meander between 09N and 12N through Fri, with gentle to moderate winds expected on either side of the trough axis through Wed. Moderate to fresh southwesterly flow and building seas to 8 or 9 ft are expected S of the monsoon trough and mainly E of 95W by Thu, likely associated with a deepening low pressure over the SW Caribbean. These marine conditions may persist through Sat. REMAINDER OF THE AREA... See Special Features above for information on Tropical Depression Rosa and Hurricane Sergio. A cold front continues to move SE across the NW waters, and extends from 30N127W to 21N140W. The front will sweep eastward across the waters north of 20N through mid week, but become diffuse before reaching 120W. This weather pattern will keep the trade wind flow minimal farther south into the deep tropics. NW swell in the wake of the front will propagate across the NW waters through Tue. Later in the week, seas associated with Sergio will mix with additional pulses of long period NW swell. By late Thu, seas of 8 ft or greater are expected to cover most of the waters N of 10N W of 105W, including the entrance of the Gulf of California. $$ GR