000 AXPZ20 KNHC 050243 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0243 UTC Fri Jul 5 2019 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 0230 UTC. ...SPECIAL FEATURES... Hurricane Barbara centered near 17.3N 131.7W at 05/0300 UTC moving NW at 10 kt. Estimated minimum central pressure is 971 mb. Maximum sustained wind speed is 85 kt with gusts to 105 kt. A west-northwest to northwest motion is anticipated tonight, followed by a gradual turn toward the west through Saturday. Rapid weakening is expected, and Barbara is forecast to weaken to a tropical storm on Friday and become a post-tropical cyclone on Saturday. See NHC Forecast/Advisory under AWIPS/WMO Headers MIATCMEP2/WTPZ22 KNHC for more details or at website https://www.nhc.noaa.gov/text/MIATCMEP2.shtml for additional details. A large area of disturbed weather associated with a tropical wave is located several hundred miles south of the southwestern coast of Mexico. This system is showing signs of organization, and a broad surface low has developed. Environmental conditions appear conducive for further development, and a tropical depression is likely to form this weekend. The low is expected to move west-northwestward at about 15 mph, remaining well off the coast of Mexico. Please see the latest eastern North Pacific tropical weather outlook for more information. ...TROPICAL WAVES... The axis of a tropical wave is near 89W, moving W around 10 kt. Scattered moderate and isolated strong convection is noted from 05N to 09N between 86W and 89W. The axis of a tropical wave remains near 96W. Scattered moderate and isolated strong convection is noted from 08N to 10N between 92W and 94W. The axis of a tropical wave is near 106W, moving W around 15 kt. Numerous moderate and scattered strong convection is noted from 11N to 15N between 103W and 109W. Scattered moderate and isolated strong convection is noted from 08N to 11N between 106W and 112W. The axis of a tropical wave is near 117W, moving W around 10 kt. Scattered moderate convection is noted from 06N to 10N between 115W and 122W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from the coast of Panama near 08N78W to 09N88W to 09N105W to 10N110W to 12N122W, then resumes from 09N132W to beyond 07N140W. Scattered moderate and isolated strong convection is noted within 60 nm of the monsoon trough between 91W and 94W, within 120 nm south of the monsoon trough between 112W and 115W, and within 180 nm south of the monsoon trough west of 134W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... The pressure gradient between a persistent high pressure ridge west of Baja California and a low pressure trough along the Gulf of California is maintaining generally moderate NW to N winds off the coast of Baja California. Earlier altimeter data off the coast of Baja California Sur showed 7-8 ft seas over the offshore waters, likely in southerly swell from distant Hurricane Barbara. Seas will subside below 8 ft by Fri as Barbara continues moving NW away from the region. Gulf of California: Gentle to moderate winds will prevail over the northern and central Gulf of California this weekend, with mainly gentle winds over the southern Gulf. Southwest gap winds will pulse to fresh speeds over the northern Gulf Sun night and Mon night. Gulf of Tehuantepec: Moderate to fresh nocturnal pulsing of northerly gap winds will begin tonight and continue through the upcoming weekend. Wind speeds are expected to diminish over the Gulf early next week as the local pressure gradient relaxes. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Strong offshore winds will prevail off the coast of Nicaragua and near the Gulf of Papagayo through Sat, then remain fresh into early next week. Elsewhere, gentle to moderate offshore winds will prevail north of the monsoon trough, while gentle to moderate S to SW winds are expected south of the monsoon trough for the next few days. Looking ahead, winds may strengthen to fresh speeds south of the monsoon trough early next week. A set of long period S to SW swell will move into the southern waters this weekend with seas building to 8 ft off the coast of Colombia and Ecuador. REMAINDER OF THE AREA... Please see the special features section for more information on Hurricane Barbara. Scatterometer data from this afternoon showed a broad area of fresh to locally strong winds south of the monsoon trough between 102W and 116W. Altimeter data and the latest wave model guidance indicated seas to 10 ft near 111W. Please see the special features section for more information on the potential for tropical cyclogenesis in this region. The pressure gradient between Hurricane Barbara and high pressure centered north of the forecast area was supporting moderate to fresh winds over the waters north of 20N based on 18Z partial scatterometer data. Earlier altimeter passes revealed that swell from Hurricane Barbara was supporting 8 ft seas or greater across much of the forecast area west of 120W. This swell will gradually subside from east to west through the weekend as Barbara weakens and tracks west-northwest. Cross-equatorial southerly swell will prevail for the next couple days across the waters generally south of 05N and west of 100W, with seas of 7-10 ft. Wave heights will subside below 8 ft by Sun as swell decays over the southern waters. $$ Reinhart