000 AXPZ20 KNHC 031544 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1544 UTC Sat Nov 3 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 FEATURE... Tropical Storm Xavier centered near 15.3N 107.0W at 03/1500 UTC moving ENE at 7 kt. Estimated minimum central pressure is 1000 mb. Maximum sustained wind speed is 45 kt with gusts to 55 kt. Westerly shear continues to influence Xavier, keeping scattered moderate to strong convection within 270 nm of the northeast semicircle of the storm. Seas over the offshore waters off SW Mexico will build as high as 18 ft in the areas of maximum winds. Swells generated from Xavier will start to impact portions of SW Mexico tonight, bringing dangerous surf and rip currents to these areas. Please consult products from your local weather office. Heavy rainfall is possible over Jalisco and the Cabo Corrientes area Sun and Mon as the system makes its closest point of approach. See latest NHC forecast/advisory under AWIPS/WMO headers MIATCMEP5/WTPZ25 KNHC for more details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A segment of the monsoon trough extends from 07N78W to 07N90W to 14N104W. Another segment reaches from west of Xavier near 13N110W to low pres near 12N119W to low pres near 10N134W to 08N136W. The intertropical convergence zone extends from 08N136W to beyond 07N140W. Scattered moderate isolated strong convection is noted from 08N to 11N between 120W and 137W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see special features section above for more on Tropical Storm Xavier, which will impact the waters off SW Mexico this weekend into early next week. Gulf of Tehuantepec: Northerly winds behind a cold front over the Gulf of Mexico continue to push into the Gulf of Tehuantepec, where strong to near gale force winds prevail. High pressure in the wake of the cold front will push eastward today, veering winds over the SW Gulf of Mexico. This will diminish winds, and resultant seas, over the Gulf of Tehuantepec through the day. Winds will diminish to 20 kt or less later this afternoon, while lingering seas will subside below 8 ft this evening. A ridge extending from 1031 mb high pressure near 37N136W to just west of the Revillagigedo Islands will continue to dominate the area through the weekend, producing a gentle to moderate anticyclonic flow. Outside of the gap wind plume pushing through the Gulf of Tehuantepec and the areas directly impacted by Xavier, moderate breezes and 4 to 6 ft seas will prevail elsewhere over the open waters. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Light to gentle winds are forecast north of the monsoon trough. Moderate to fresh southwest monsoon flow is expected south of the monsoon trough through the weekend. REMAINDER OF THE AREA... Outside of Tropical Storm Xavier, two other centers of low pressure are embedded within the monsoon trough. One of these is centered near 12N119W with an estimated pressure of 1009 mb. A recent altimeter satellite pass showed seas at 8 ft within 90 nm north of the low, likely the result of fresh to strong near the low center. Elsewhere recent scatterometer data shows trade winds remain fairly weak between the low pressure centers the subtropical ridge north of 20N. Moderate southerly flow is noted south of the monsoon trough, with 5 to 7 ft seas everywhere west of 120W in mixed swell. Northerly swell will propagate into the northern waters tonight, which will build seas to 8 ft over the waters N of 28N between 124W and 136W. The swell will continue to spread SW, with seas 8 ft or greater covering the waters NW of a line from 30N123W to 25N140W by late Sun night. $$ Christensen