000 AXPZ20 KNHC 172124 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 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 1800 UTC surface analysis and satellite imagery through 2100 UTC. ...TROPICAL WAVE... A new tropical wave has entered the eastern Pacific with an axis along 83W from 03N to the coast of Costa Rica moving W at 15 kt. Scattered moderate to isolated strong convection is found near the axis from 04N to 10N between 82W and 87W. A tropical wave is along 103W and N of 02N, moving W at 15 to 20 kt. The wave extends along the coast of Michoacan. Scattered moderate to isolated strong convection is noted from 04N to 18N between 100W and 109W. A tropical wave is along 121W from 02N to 18N, moving W at 10 to 15 kt. Scattered moderate convection is observed from 04N to 12N between 118W and 123W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A monsoon trough extends off the coast of Costa Rica near 09N83W to 08N98W to 08N109W. The ITCZ extends from 08N110W to 08N120W then from 07N123W to beyond 05N140W. Scattered moderate to isolated strong convection from 02N to 18N between 77W and 110W. Scattered moderate convection is noted from 02N to 10N between 112W 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 from high pressure extending over the Gulf of Mexico. Seas are likely near 7 ft downstream in the Gulf of Tehuantepec mixing with longer period southerly swell moving into the region. Farther north, weak ridging persists over most of the area. This is leading to gentle to moderate winds and slight to moderate seas. Scattered thunderstorms are noted south of Michoacan associated with the tropical wave along 103W. Some of these storms are producing gusty winds and seas up to 7 ft. For the forecast, the fresh to strong northerly winds are forecast to persist in the Tehuantepec region through Thu week with seas building to 8 ft. Farther north, a weak ridge will continue to dominate the Baja California offshore waters through most of the week. This will maintain gentle to moderate NW winds and slight to moderate seas. The Gulf of California can expect seas of 3 ft or less. ...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Fresh to locally strong NE to E winds prevail across the Papagayo region and downwind to about 95W. Seas to 7 ft are within these winds. Light to gentle winds and seas of 3 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 3 to 5 ft. Numerous thunderstorms are noted across the Costa Rica and Panama offshore waters associated with a tropical wave along 83W. Scattered thunderstorms are also noted in the Colombia offshore waters. For the forecast, the fresh to strong NE to E winds are forecast to pulse in the Papagayo region through Thu night with seas building near 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 6 ft in mostly S to 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... T.S. Calvin has moved west of the area. Please see the latest forecast/advisory and Public Advisory from the Central Pacific Hurricane Center at www.hurricanes.gov for more details. The latest scatterometer pass shows strong winds from the influences of T.S. Calvin extend over a small portion of the western forecast waters, from 17N to 20N and W of 139W. Seas are 8 to 12 ft from 14N to 23N and W of 137W. These conditions will improve quickly with the strong winds ending in a few hours and seas dropping below 8 ft by Tue morning. Aside from Calvin, a ridge prevails across the north waters anchored by a 1028 mb high pressure center located north of the area near 37N138W. Gentle to moderate NE winds are noted N of the ITCZ/monsoon trough and W of 115W due to the influence of the ridge. Seas range 4 to 7 ft. Winds are moderate to locally fresh S of the ITCZ/monsoon trough with seas 4 to 6 ft. Wind and seas could be higher near the convective activity along the ITCZ/monsoon trough. For the forecast, fresh to strong winds and moderate to rough seas will develop along a tropical wave as it moves westward from 10N to 15N between 105W and 120W. Northerly swell could impact the northern waters later today through Tue evening, bringing seas near 8 ft N of 28N between 127W and 131W. Otherwise, moderate to locally fresh winds with moderate seas can be expected N and S of the ITCZ/monsoon trough through the rest of the week. $$ AReinhart