000 AXPZ20 KNHC 270336 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 UTC Tue Jun 27 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 0000 UTC surface analysis and satellite imagery through 0240 UTC. ...SPECIAL FEATURE... Off the Southern and Southwestern Coast of Mexico (EP91): Showers and thunderstorms are beginning to show signs of organization associated with an area of low pressure located several hundred miles south of the southwestern coast of Mexico. Environmental conditions appear generally favorable for development of this system, and a tropical depression is likely to form during the middle part of this week as the system moves slowly west-northwestward, parallel to the southwestern coast of Mexico. With this, there is a medium chance for tropical formation within the next 48 hours and a high chance for the next 7 days. ...TROPICAL WAVES... A tropical wave, the remnants of former Atlantic tropical cyclone Bret, is analyzed along 85W, from 08N into the Gulf of Honduras, moving W at 5 to 10 kt. Associated convection is described below and prevails between 82W and 95W. A tropical wave is re-positioned along 115W from 07N to 18N, moving W at 5 to 10 kt. Associated convection is described below and prevails between 107W and 115W. A tropical wave is analyzed along 135W from 03N to 14N, moving W at 10 kt. No significant convection is noted with this wave. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A monsoon trough extends from 09.5N75W to 08.5N88W to 1008 mb low pres near 15N101.5W to 1006 mb low pres near 13.5N113W to 06N129W. The ITCZ continues from 06N130W to beyond 04N140W. Scattered to locally numerous moderate to strong convection is noted N of 04.5N between 82W and 95W, and from 07.5N to 16N between 98W and 105W. Scattered moderate to strong convection is noted from 11N to 16N between 107W and 115W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A broad surface ridge extends southeastward into the region to near 24N114W, and is supporting fresh to strong northerly winds and 6 to 9 ft seas across the Baja California waters north of Cabo San Lazaro. In the Gulf of California, light to gentle northerly winds prevail across north sections and are southerly elsewhere. Seas across the central and southern Gulf are up to 4 ft. Moderate to fresh E-SE winds are occurring across the nearshore waters of Guerrero and Michoacan, where seas are 6 to 7 ft. Winds are generally light elsewhere, except for fresh NW winds in the immediate waters of central Gulf of Tehuantepec. Seas of 5 to 6 ft prevail across these remaining Mexican offshore waters. For the forecast, the broad surface ridge will persist across offshore waters W of 110W through tonight before weakening modestly as high pressure reorganizes farther NW of the area. A tight pressure gradient between the ridge and a meandering trough over western Mexico will continue to support pulsing fresh to strong winds from Cabo San Lazaro northward tonight, then shift N of Punta Eugenia Tue through Wed. Pulsing fresh southerly winds expected across the south and central Gulf of California during overnight hours. A broad area of low pressure is expected to become better organized on Tue offshore of southern Mexico. As this occurs, expect fresh to strong winds to shift westward across the nearshore waters of southwestern Mexico. Environmental conditions appear favorable for gradual development of this broad system. A tropical depression is likely to form during the middle part of this week as the system moves generally west- northwestward, and parallel to the southwestern coast of Mexico. Refer to the latest NHC Tropical Weather Outlook at www.hurricanes.gov for more details. Another low pressure may form offshore of El Salvador and Guatemala Tue night or Wed move west-northwestward and just offshore of the Tehuantepec region Wed night and Thu. ...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Light to gentle W to SW winds and seas at 4 to 6 ft prevail across the offshore waters S of 09N. Across the offshore waters of Colombia, Ecuador and Galapagos Islands, moderate S to SW winds and seas of 5 to 6 ft in southerly swell persist. For the forecast, gentle to moderate winds and slight to moderate seas will continue across the offshore waters of Central America through mid-week, except moderate to fresh offshore winds across the Papagayo region. For the waters offshore from Colombia, Ecuador and the Galapagos Islands, moderate to fresh S to SW winds and moderate seas in southerly swell are expected during the period. Low pressure may form offshore of El Salvador and Guatemala Tue night or Wed. Some gradual development of this system is possible thereafter as it moves slowly west- northwestward, remaining offshore of the southern coast of Mexico. Looking ahead, new moderate-sized SW swell will cross the equator and into the waters of Colombia, Ecuador and the Galapagos Islands Fri night through Sat night. ...REMAINDER OF THE AREA... Refer to the section above for details on the tropical waves moving across the area. High pressure well NW of the area extends a broad surface ridge southeastward to offshore of Baja California Sur. The pressure gradient to the south of the ridge axis is supporting moderate to fresh N to NE winds and 6 to 10 ft seas from 09N to 25N and west of 125W, and N of 15N between 120W and 125W. Gentle northerly winds and 4 to 5 ft seas prevail north of 25N west of 130W. Light to gentle winds and 6 to 9 ft seas in SW swell are noted from S of 12N and W of 100W. For the forecast, the surface ridge will sink southward and weaken through Wed, as the anchoring high pressure center reorganize to the NW. This should maintain moderate to fresh trade winds S of 25N, and seas in the 6 to 9 ft range. Strong SW monsoonal winds will develop between 100W and 115W from tonight through Thu, and shift W-NW through Thu, generating seas to 9 ft. Looking ahead, new moderate-sized SW swell will cross the equator Fri night through Sat night and raise sea heights to 7 to 8 ft E of 130W and S of 10N. $$ Stripling