703 AXPZ20 KNHC 171554 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Mon Jul 17 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 1200 UTC surface analysis and satellite imagery through 1530 UTC. ...SPECIAL FEATURES... Tropical Storm Calvin is centered near 16.7N 140.5W at 17/1200 UTC moving W at 16 kt. Estimated minimum central pressure is 1000 mb. Maximum sustained wind speed is 45 kt with gusts to 55 kt. Scattered moderate convection is noted within 60 nm of the northern semicircle from the center. Seas 12 ft or greater are estimated to be within 210 nm in the northern semicircle and 90 nm in the southern semicircle with seas to 20 ft E of 140W. Calvin is expected to approach the main Hawaiian Islands on Tuesday and early Wednesday, bringing the potential for heavy rainfall and dangerous surf and rip current conditions.. Please read the latest CPHC Public Advisory at https://www.nhc.noaa.gov/text/MIATCPCP1.shtml and Forecast/ Advisory at https://www.nhc.noaa.gov/text/MIATCMCP1.shtml for more 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 T.S. Calvin Forecast/Advisory and Public Advisory at www.hurricanes.gov for more details. ...TROPICAL WAVE... A tropical wave is along 101W and N of 03N, moving W at 10 to 15 kt. The wave extends northward across the Gulf of Tehuantepec. Scattered moderate to isolated strong convection is evident from 05N to 17N between 95W and 108W. A tropical wave is along 119W from 03N to 18N, moving W at 10 to 15 kt. Scattered moderate convection is observed from 05N to 10N between 116W and 122W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A monsoon trough extends from the coast of Costa Rica near 10N86W to 09N102W to 05N124W. The ITCZ extends from 05N124W to beyond 04N140W. Scattered moderate convection is noted from 06N to 12N between 83W and 135W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Fresh to strong northerly gap winds are noted in the Gulf of Tehuantepec. This is due to a tighter pressure gradient between higher pressure over the Gulf of Mexico and relatively lower pressure farther south assisted by the passage of a tropical wave through the region. Seas are likely as high as 7 ft downstream in the Gulf of Tehuantepec, mixing with longer period southerly swell moving into the region. Farther north, weak ridging persists, maintaining gentle to moderate winds and slight to moderate seas. Scattered storms are noted around Cabo Corrientes and south of Michoacan. For the forecast, the fresh to strong northerly winds are forecast to persist in the Tehuantepec region through most of the week with seas building to 8 ft. Farther north, a ridge will continue to dominate the offshore forecast waters of Baja California through at least mid-week supporting gentle to moderate NW winds with seas in the 4 to 6 ft range, and in the Gulf of California with seas of 3 ft or less. ...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 90W. 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, the fresh to strong NE to E winds are forecast to pulse in the Papagayo region through most of the week with seas building to 8 ft. Light to gentle winds will dominate most of the offshore forecast waters. Gentle to moderate southerly winds can be expected between Ecuador and the Galapagos Islands, and moderate to locally 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 T.S. Calvin that is moving westward toward the central Pacific basin. Aside from Calvin, a ridge prevails across the north waters anchored by a 1028 mb high pressure center located north of the area near 37N137W. 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, Calvin will move west of 140W through early Mon. Seas generated by Calvin will subside to less than 8 ft east of 140W by Mon afternoon. Farther east, expect fresh to strong winds and moderate to rough seas from 10N to 15N between 105W and 120W as a weak impulse moves along the monsoon trough through mid week. $$ AReinhart