000 AXPZ20 KNHC 260359 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 UTC Tue May 26 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 0000 UTC surface analysis and satellite imagery through 0245 UTC. ...TROPICAL WAVES... The axis of a tropical wave is along 96W from 04N to 15N, moving westward at 10-15 kt. This wave is embedded in a very moist surrounding environment. Clusters of scattered moderate to strong are noted within 60 nm east of the wave from 08N-11N, and within 30 nm of line from 08N90W to 08N95W. Deep convection west of the wave is associated with the monsoon trough as described below. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from a 1008 mb low over northwestern Colombia southwestward to the coast at 07N78W and continues to 09N95W to 11N92W to 11N100W to a 1008 mb low near 09N106W and to 09N120W to a 1011 mb low near 10N131W and to 09N135W, where scatterometer data from Mon afternoon indicates that it transitions to the ITCZ to beyond the area at 09N140W. Scattered moderate to strong convection is within 180 nm south of the trough between 94W-99W, within 120 nm south of the trough between 99W-102W and also between 106W-109W and within 60 nm of the trough between 81W-85W. Scattered moderate to isolated strong convection is within 120 nm south of the trough between 90W-94W. Scattered moderate convection is within 60 nm north of the ITCZ between 126W-128W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A ridge extends from high pressure centered north of the area near 34N138W southeastward toward the Revillagigedo Islands. Gentle to moderate northwest winds offshore of Baja California as were highlighted by ASCAT data from Mon afternoon are due to the pressure gradient between the ridge and deep low pressures over inland Mexico. Wave heights offshore Baja California are in the 4-6 ft range. Light and variable winds remain over the Gulf of California, where wave heights are low, in the 0-2 range. The high pressure will weaken through Thu, with little change to present marine conditions. Southwest swell will build seas slightly over the waters south of Tehuantepec Wed through late this week. Agricultural fires in Mexico will continue to produce hazy skies near the coast of southern Mexico. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... ASCAT data from Mon afternoon showed gentle to moderate south to southwest winds south of the monsoon trough, with light to gentle winds elsewhere. Wave heights due to a southwest swell are in the range of 4-6 ft per latest altimeter data passes. the offshore waters of Costa Rica and Panama per recent altimeter data. Gentle to moderate monsoon flow will prevail over the next few days. Long-period SW swell will continue impacting the offshore waters through at least Wed. with wave heights building to near 8 ft SW of the Galapagos Islands by that time. A broad area of low pressure is expected to form later this week offshore of southern Mexico, Guatemala, and El Salvador. This system will bring increasing winds and seas, along with gusty showers and thunderstorms, to the offshore waters by Thu or Fri. REMAINDER OF THE AREA... A ridge extends from high pressure of 1027 mb centered north of the area near 35N138W southeastward across the northern waters. Gentle to moderate northeast winds continue between this ridge and the monsoon trough/ITCZ per recent scatterometer data. Increasing clusters of numerous moderate to isolated strong convection are noted within 180 nm in the SW quadrant of a 1008 mb low that is along the monsoon trough near 09N106W. The latest ASCAT data indicated moderate to fresh winds west and southwest of this low to near 112W. Elsewhere, moderate, to at times fresh, south to southwest winds are south of the monsoon trough between 92W-98W and also between 102W-112W. Farther south, cross-equatorial southwest swell is producing wave heights in the range of 7-10 ft south of 08N and between 99W-120W. This swell will continue to propagate northeastward through Wed, then gradually begin to decay. High pressure will weaken over the northern waters as an upper- level pressure system induces a surface trough/low near 26N131W by Wed morning. Expect fresh winds along with wave heights building to 8 ft northwest of the low Wed into Thu as it remains nearly stationary. The low near 09N106W will drift northeastward along the monsoon trough over the next couple days, with fresh winds and locally higher wave heights expected south and southeast of the low center. Scattered to numerous showers and thunderstorms are expected with the low as it moves into through a very moist and unstable atmospheric environment. $$ Aguirre