532 AXPZ20 KNHC 081534 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Sat Jul 8 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 1515 UTC. ...SPECIAL FEATURE... Offshore of Southwestern Mexico (EP93): Showers and thunderstorms continue to gradually become better organized in association with a large area of low pressure located a few hundred miles southwest of Manzanillo, Mexico. Presently, numerous moderate to isolated strong convection in what appears to be developing bands are noted from 09N to 18N between 100W-113W. An overnight scatterometer pass showed winds of 20-30 kt to the SE of the low center. An overnight altimeter pass shows seas to 12 ft within this area of near-gale force winds. Environmental conditions are expected to remain conducive for slow development, and a tropical depression is likely to form later today or tonight while the disturbance moves generally west-northwestward, away from the coast of mainland Mexico. In anticipation of this, a Gale Warning has been issued for the outer offshore waters of SW Mexico. There is a high chance of tropical formation in the next 48 hours. Refer to the latest NHC Tropical Weather Outlook at www.hurricanes.gov for more details. ...TROPICAL WAVES... The axis of a tropical wave is near 87W north of 05N. It is moving westward at 10 kt. Associated convection is described below. The axis of a tropical wave is near 107W-108W from 07N to 21N. This wave is co-located with EP93, discussed above. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from northwest Colombia to across the border between Nicaragua and Costa Rica and to 11N86W to 15N100W to low pressure (EP93) near 16N108W 1005 mb to 12N117W to 10N124W and to 06N123W. The ITCZ extends from 06N123W to 06N140W. Scattered moderate to isolated strong convection is seen within 60 nm of the trough between 86W-92W. Scattered moderate convection is within 180 nm south of the trough between 92W-100W, also from 07N to 10N between 111W-117W, and within 60 nm south of the trough between 125W-134W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see the SPECIAL FEATURES section above for information more on EP93. Aside from EP93, a surface ridge dominates the offshore forecast waters of Baja California. Moderate to locally fresh NW winds are noted over the Baja California Norte offshore waters with gentle to moderate NW winds elsewhere across the Baja California offshore waters. Seas over this area are in the 5-7 ft range in a mix of northerly and southerly swell. In the Gulf of California, gentle to moderate southerly winds prevail with seas ranging 2-4 ft except to 5 ft in southerly swell across the entrance. Gentle to moderate winds are noted elsewhere across the Mexico offshore waters N of Cabo Corrientes with 5-6 ft seas in southerly swell. Light to gentle winds and seas of 6-7 ft are found over the Tehuantepec region. For the forecast, a broad surface ridge will persist across the regional waters through early next week. Winds off of Baja California Norte will pulse to fresh at night through the weekend. An large area of low pressure (EP93) located several hundred miles SW of southwestern Mexico continues to gradually become better organized. A tropical depression is likely to form from this disturbance later today or tonight while the disturbance moves generally west-northwestward away from the coast of mainland Mexico. A Gale Warning is now in effect for the outer offshore waters W of 108W. A trough of low pressure located a few hundred miles south-southeast of southern Mexico is producing disorganized showers and thunderstorms. Environmental conditions are forecast to be conducive for gradual development during the next several days, and a tropical depression is likely to form during the early to middle portions of next week. The system is expected to move westward to west-northwestward parallel to, but well offshore of the coast of southern and southwestern Mexico. This second system has a low chance of formation in the next 48 hours and a high chance in the next 7 days. ...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Light to gentle winds are noted north of 02N, with seas of 6-7 ft in south-southwest swell. Gentle to moderate winds are found south of 02N, where seas are also 6-8 ft in southerly swell. For the forecast, gentle to moderate winds will prevail over the next several days. Southerly swell will subside across the regional waters today. Low pressure is expected to form S of Tehuantepec late Sun or Mon leading to freshening winds across the waters W of 90W. Fresh gap winds across the Papagayo region starting Sun will pulse to strong at night Mon through Wed. ...REMAINDER OF THE AREA... High pressure prevails north of 20N, anchored by a 1026 mb surface high well NW of the area near 39N146W. Gentle to moderate northeast winds and seas of 5-8 ft in southerly swell prevail north of the ITCZ and monsoon trough west of about 120W. To the south of the ITCZ and monsoon trough, gentle to moderate S winds are noted. Large swell from the Southern Hemisphere continues to produce seas of 7-8 ft across the waters S of 10N and W of 90W. For the forecast, high pressure will remain in place over the northern waters today, then shift slightly SE Sun through Mon. This will increase winds N of the ITCZ and monsoon trough to moderate to locally fresh, with seas in the 5-7 ft range. Cross- equatorial southerly swell in the southern waters will subside today. Northerly swell will move into the waters E of 125W today to raise seas there to around 9 ft, then combine with SE to E swell generated by EP93, across the waters E of 130W on Mon and Tue. $$ Aguirre