000 AXPZ20 KNHC 270952 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 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 0600 UTC surface analysis and satellite imagery through 0850 UTC. ...SPECIAL FEATURE... Off the Southern and Southwestern Coast of Mexico (EP91): Showers and thunderstorms are showing 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. South of Southern Mexico and Central America: A broad area of low pressure associated with disorganized showers and thunderstorms is located a few hundred miles south of the coasts of Guatemala and El Salvador. Some gradual development of this systems is possible during the next several days, and a tropical depression is likely to form during the middle to latter part of this wee, while it moves slowly west-northwestward to northwestward, and roughly parallel to the southern and southwestern coasts of Mexico. This system has a medium chance of tropical formation within the next 48 hours, and a high chance through 7 days. Refer to the latest NHC Tropical Weather Outlook at www.hurricanes.gov for more details on both of these features. ...TROPICAL WAVES... A tropical wave, the remnants of former Atlantic tropical cyclone Bret, is analyzed along 85W-86W, from 08N into the Gulf of Honduras, moving W at 5 to 10 kt. Associated convection is described below and prevails between 82W and 92W. A tropical wave has been added to the 0600 UTC surface analysis, located along 102W-103W, extending from 12N to 20N. Overnight ASCAT data depicted a surface low near 15.5N102.5W that is analyzed at 1008 mb. Deep convection has developed west of the surface low and is described below, prevailing between 102W and 106W. More information on this wave is described in the special features section above. A tropical wave is analyzed along 116W from 07N to 18N, moving W at 10 kt. Associated convection is described below and prevails between 112W and 119W. A 1006 mb surface low pressure center is located near 13.5N113W, as depicted in overnight ASCAT data. Both the wave and surface low are part of an elongated low to middle level cyclonic circulation that shows up well in PW products. A tropical wave is along 136W 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 10N75W to 09N81W to 1008 mb low pres near 15.5N103W to 1006 mb low pres near 14N112.5W to 06.5N129W. The ITCZ continues from 06.5N13W to beyond 04N140W. Scattered to locally numerous moderate to strong convection is noted N of 02.5N between 82W and 93W, and from 06N to 11.5N between 93W and 102W. Numerous moderate to strong convection is noted from 10N to 16.5N between 102W and 106.5W. Scattered moderate isolated strong convection is noted from 08N to 11N between 112W and 119W, and from 13N to 16N between 113W and 116W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A broad surface ridge extends southeastward into the region to near Cabo San Lazaro, and is supporting fresh to strong northerly winds and 6 to 9 ft seas across the Baja California offshore waters north of 25N. In the Gulf of California, light and variable winds prevail across north sections, with moderate to locally fresh southerly elsewhere. Seas across the and southern Gulf are up to 5 ft. Moderate to fresh E-SE winds were depicted by overnight scatterometer data across the nearshore waters of Guerrero and Michoacan, where seas are 6 to 8 ft. A 1008 mb surface low center is located there near 15.5N103W. Very active convection has developed to the S and SW of the low overnight. Winds are generally light to moderate 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 surface ridge across offshore waters will weaken modestly through mid-week as high pressure reorganizes farther NW of the area. Fresh to strong winds will continue N of Punta Eugenia through Wed. Pulsing fresh southerly winds expected across the south and central Gulf of California during overnight hours. See the special features section above for more information on the low pressure center off of southwestern Mexico. This area of low pressure is expected to become better organized offshore of southern Mexico through Wed. As this occurs, expect fresh to strong winds to shift westward across the nearshore waters of southwestern Mexico. 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 7 to 10 ft seas from 07N to 25N and west of 127W, and N of 15N between 120W and 127W. 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 drift 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 8 or 9 ft range. Strong SW monsoonal winds will develop between 100W and 118W 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