595 AXPZ20 KNHC 021630 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 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 1200 UTC surface analysis and satellite imagery through 1500 UTC. ...SPECIAL FEATURES... Satellite imagery and surface observations this morning suggest that Rosa has become disturbed overnight as it moves across Baja California Norte, with its remnants appearing as a series of low level cloud swirls seen over water along the east coast of the peninsula between Isla San Juan de la Guarda and San Felipe. A mean or central location of lowest pressure is estimated near 29.7N 114.2W at 1005 mb, at 1500 UTC, generally moving NE at 7 kt. Maximum sustained winds are confined within the northern Gulf of California at 25 kt with gusts to 35 kt. These southerly winds occurring north of the Tiburon Basin are producing seas 6 to 10 ft. The middle level circulation of Rosa remnants is moving NNE across the Desert Southwest of the U.S. this morning and will pose a heavy rain threat to the region during the next 24-36 hours. SW swell previously generated by Rosa will continue to affect portions of the coasts of southwestern Mexico, most of the west coast of the Baja California peninsula, and southern California as it gradually fades today. These swells will produce large and powerful surf and create life-threatening rip currents within the surf zone. See latest NHC forecast/advisory under AWIPS/WMO headers MIATCMEP5/WTPZ25 KNHC for more details. Hurricane Sergio continues to strengthen this morning, and was located near 10.6N 114.0W at 1500 UTC, or about 775 nm SSW of the southern tip of Baja California, moving W at 11 kt. Maximum sustained wind speed has increased to 85 kt with gusts to 105 kt. Estimated minimum central pressure is 978 mb. 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 strong convection is noted within 90 nm of center. Numerous moderate to strong convection is seen elsewhere within 150 nm N and 180 nm S of the 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 near 10N72W TO 08N80W TO 12.5N107W, where it breaks from Sergio. The trough then resumes from 15N121W to beyond 10N140W. Scattered moderate to strong convection is within 180 nm S of the trough between 77W and 105W, and from 09N to 15N between 125W and 133W. Scattered moderate to strong convection is from 12N to 16.5N between 94W and 103W, and from 20N to 23.5N to the east of 107.5W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... See Special Features above for information on the remnants of Rosa and Hurricane Sergio. Swell associated with Rosa is still affecting the offshore forecast waters W of Baja California, particularly N of 24N E of 118W, where early morning altimeter data showed seas 6 to 10 ft and highest near Punta Eugenia. These seas will subside today and allow seas to diminish to less than 7 ft by afternoon. However, further south, S to SE swell generated by Sergio, is propagating northward to the waters offshore of Cabo Corrientes to Cabo San Lucas, and will build to 6-8 ft by early afternoon. These swell have been impacting the waters and coastal ones from Guerrero to Cabo Corrientes overnight and will continue to produce dangerous surf conditions in the coastal areas during the next few days. In the Gulf of California, conditions associated with the remnants of Rosa are described above and will gradually subside today. The southerly swell from Sergio will move into southern portions of the Gulf today and raise wave heights to 4-7 ft and increase to 5-8 ft Wed night and Thu and Sergio continues to intensify. Large and dangerous surf will impact coastal areas inside the southern Gulf through at least late thu. Gentle NW to W winds are expected across most of the Gulf Wed and Thu, while variable winds will prevail across far north portions. In the Gulf of Tehuantepec, offshore northerly gap winds of 20 to near 25 kt are expected to pulse to near 30 kt during the overnight and early morning hours through at least early Wed morning. Seas are forecast to build to 9 or 10 ft during the hours of 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 Hurricane Sergio. A cold front continues to move SE across the NW waters, and extends from offshore of southern California through 30N126W to 2.5N140W. The front will sweep eastward across the waters north of 20N through mid week, but become diffuse before reaching 120W. This pattern will keep the trade wind flow minimal farther south into the deep tropics, due to a very weak pressure gradient. NW swell in the wake of the front will propagate across the NW waters today. 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. $$ Stripling