000 AXPZ20 KNHC 252153 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 UTC Tue Aug 25 2020 Tropical Weather Discussion for the eastern Pacific Ocean from the Equator to 32N, east of 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. ...SPECIAL FEATURES... A 1006 mb low pressure system is located a few hundred miles S-SE of the southern tip of the Baja California peninsula near 16.5N107.5W. Showers and thunderstorms have become better organized during the past several hours and the surface circulation has become a little better defined. Numerous moderate to strong convection is noted within 60 nm in the NE semicircle and within 180 nm in the SW semicircle of the low. Although upper-level winds are marginally conducive for further development, a tropical depression is likely to form during the next day or two while the system moves slowly east-northeastward to northeastward toward the southwestern coast of Mexico. A gale warning has been issued with current winds of fresh to strong forecast to reach gale force by late tonight. Seas of 8-11 ft will build as the winds increase. The latest Tropical Weather Outlook states that this system has a high change of tropical cyclone formation through 48 hours. Satellite derived wind data indicate that the small low pressure system that was located just off of the coast of S-central Mexico near Puerto Angel has opened up into a trough of low pressure. Consequently, development of this system appears to be less likely. Regardless of development, areas of heavy rainfall and flash flooding are likely in southeastern Mexico and northern Central America during the next several days. The latest Tropical Weather Outlook gives this system a medium chance of tropical cyclone formation through 48 hours. A 1004 mb low pressure system is located several hundred miles SW of the southern tip of the Baja California peninsula near 15N117.5W. Scattered moderate to strong convection is noted within 90 nm in the W quadrant, with scattered moderate convection elsewhere from 13N to 17N between 118W and 124W. Scatterometer data indicated that fresh to strong winds are occurring near the low, along with seas of 8-12 ft. Gradual development of this system is possible during the next couple of days, and a tropical depression could form while it moves slowly east-northeastward. The latest Tropical Weather Outlook gives this system a medium chance of tropical cyclone formation through 48 hours. Please refer to the latest NHC Tropical Weather Outlook at www.hurricanes.gov for more details on all of these systems. ...TROPICAL WAVES... A tropical wave axis is near 90W, moving westward at 15 to 20 kt. Associated convection is described in the section below. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from the SW Caribbean Sea near 11N76W to across Central America to low pressure near 15.5N97W to low pressure near 16.5N107.5W to low pressure near 15N117.5W to 11N124W to 11N133W to low pressure near 12.5N140W. The monsoon trough is active, with numerous moderate and isolated strong convection noted N of 04N and E of 86W, N of 08N between 86W and 90W, N of 10N between 90W and 106W, and from 13N to 15N and W of 137W. Scattered moderate convection is noted from 07N to 10N between 124W and 138W. As typical with an active monsoon trough, there are several areas of low pressure embedded within the monsoon trough. Three of these areas are being monitored for tropical cyclone potential. Please see Special Features section above for more information. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see the Special Features section for details on several areas of disturbed weather along the monsoon trough that may impact the offshore waters of Mexico this week and upcoming weekend. High pressure prevails over the waters W of Baja California. A locally tight pressure gradient will develop tonight into early Wed N of Sebastian Vizcaino Bay briefly increasing NW-N winds to fresh to strong. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, and WITHIN 750 NM OF ECUADOR... Moderate to fresh SW to W winds are expected across the offshore waters of Guatemala and El Salvador through Wed night. Fresh to strong SW winds are expected across the offshore waters of Costa Rica and Panama through Wed night before diminishing. Long-period S-SW swell will propagate into the waters offshore of Ecuador by early Thu with seas building to 7-9 ft. These seas will decay by the end of the week. REMAINDER OF THE AREA... A ridge dominates the northern forecast waters N of 20N. A cold front analyzed just W-NW of 30N140W will stall out through Wed with little impact across the discussion waters. A 1009 mb low pressure area is near 12.5N140W with associated convection described above. Scatterometer and altimeter data shows a small area of fresh to strong winds and seas to 8 ft from 15N to 16N to the W of 139W. The low pressure will move W of the forecast area by tonight, with associated winds and seas decreasing over the discussion waters. Fresh to locally strong SW winds prevail S of the monsoon trough between 95W and 120W. $$ Lewitsky