506 AXPZ20 KNHC 160858 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Sun Jul 16 2023 Tropical Weather Discussion for the eastern Pacific Ocean from 03.4S to 30N, east of 120W including the Gulf of California, and from the Equator to 30N, between 120W and 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 0830 UTC. ...SPECIAL FEATURES... Hurricane Calvin is centered near 15.7N 133.4W at 16/0900 UTC moving WNW at 15 kt. Estimated minimum central pressure is 982 mb. Maximum sustained wind speed is 70 kt with gusts to 90 kt. Numerous moderate to strong convection is noted within 140 nm of center. Seas in excess of 12 ft seas extend within 180 nm N semicircle and 90 nm S semicircle with maximum seas estimated to reach 30 ft. On the forecast track, the center of Calvin will move into the central Pacific basin overnight Sunday into Monday morning while the weakening trend continues. Swells generated by Calvin are expected to begin reaching the Hawaiian Islands in a couple of days. These swells are likely to cause life-threatening surf and rip current conditions. Please consult products from your local weather office for details. Please read the latest HIGH SEAS FORECAST issued by National Hurricane Center at web-site https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml and the latest Hurricane Calvin Forecast/Advisory and Public Advisory at www.hurricanes.gov for more details. ...TROPICAL WAVE... A tropical wave is along 90W and N of 03N, moving W at 10 to 15 kt. The wave extends northward over central America. Scattered moderate convection is noted along the northern half of the wave mainly N of 12N. A second tropical wave is along 110W from 03N to 18N, moving W at 10 to 15 kt. Scattered showers prevail along the wave axis. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 10N86W to 10N127W. The ITCZ stretches from 08N136W to beyond 07N140W. Scattered moderate convection prevails from 02N to 15N between 92W and 121W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A surface ridge dominates the offshore forecast waters of Baja California and extends SE beyond the Revillagigedo Islands. Gentle to moderate NW winds prevail with seas of 4 to 6 ft. Light to gentle southerly winds are over the Gulf of California where seas are in the 1 to 3 ft range with the exception of 3 to 4 ft near the entrance to the Gulf. Fresh to strong northerly winds prevail in the Tehuantepec region with seas of 4 to 6 ft. Elsewhere across the remainder of the Mexican offshore waters, light to gentle winds and seas of 4 to 5 ft in SW swell are noted. For the forecast, the ridge will continue to dominate the offshore forecast waters of Baja California through Tue supporting gentle to moderate NW winds with seas in the 4 to 5 ft range. Similar wind speeds are expected in the Gulf of California with seas of 3 ft or less. By Wed, winds and seas will increase some over the Gulf of California. At that time, moderate to fresh southerly winds and seas of 2 to 4 ft are expected with the highest seas over the northern part of the Gulf. Fresh to strong northerly winds are forecast to pulse in the Tehuantepec region through mid-week with seas building to 7 ft. ...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Fresh to strong NE to E winds prevail across the Papagayo region and downwind to about 89W. Seas are 5 to 7 ft within these winds. Light to gentle winds and seas of 4 to 5 ft are noted over the remainder of the offshore waters north of 03N. Gentle to moderate southerly winds are observed south of 03N where seas are 4 to 6 ft. For the forecast, fresh to strong NE to E winds are forecast to pulse in the Papagayo region through the middle of the week with seas of 5 to 7 ft. Light to gentle winds will dominate the remainder of the offshore forecast waters, with the exception of gentle to moderate southerly winds between Ecuador and the Galapagos Islands, and moderate to fresh NE to E winds across the offshore waters of Guatemala and El Salvador. Outside of the Papagayo region, seas of 4 to 5 ft in SW swell are expected. However, seas generating in the Papagayo area will spread across the offshore waters of Guatemala and El Salvador building seas to 5 to 7 ft. ...REMAINDER OF THE AREA... Please see the SPECIAL FEATURES section above for more information on Hurricane Calvin. Aside from Calvin, a ridge prevails across the north waters anchored by a 1025 mb high pressure center located N of the area near 37N138W. Gentle to moderate winds are noted under the influence of the ridge. Wind and seas could be higher near the convective activity along the ITCZ/Monsoon Trough. For the forecast, Hurricane Calvin will weaken to a tropical storm near 16.2N 135.8W this afternoon, move to 16.7N 139.1W Mon morning, 17.2N 142.6W Mon afternoon, 17.6N 146.1W Tue morning, 18.2N 149.6W Tue afternoon, and 18.6N 153.2W Wed morning. Calvin will weaken to a tropical depression over 19.9N 160.0W early Thu. Seas in excess of 8 ft generating by Calvin, will continue to propagate across the open waters, covering the area from 11N to 23N and W of 125W through Mon. An area of fresh to strong E winds, with seas to 8 ft is forecast to develop to the S and SW of the Tehuantepec region by Mon and could be associated with a developing low pressure along the monsoon trough. $$ ERA