000 AXPZ20 KNHC 122205 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 UTC Mon Aug 12 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 1800 UTC surface analysis and satellite imagery through 2145 UTC. ...SPECIAL FEATURES... Tropical Storm Henriette is centered near 20.3N 113.1W at 12/2100 UTC moving WNW at 11 kt. Estimated minimum central pressure is 1005 mb. Maximum sustained wind speed is 35 kt with gusts to 45 kt. Dry air and northeasterly shear have been negatively influencing Henriette during the afternoon. Latest satellite imagery shows that the low-level center of the cyclone has become exposed with deep convection of the scattered moderate to isolated type located within 90 nm of the center in the SW quadrant. Scattered moderate convection is elsewhere from 15N to 17N between 113W and 117W. Henriette is forecast to weaken to a tropical depression near 20.9N 114.8W Tue morning, become a remnant low and move to 21.6N 117.1W Tue afternoon, 22.1N 119.7W Wed morning, and dissipate Wed afternoon. See latest NHC forecast/advisory under AWIPS/WMO headers MIATCMEP4/WTPZ24 KNHC for more details. ...TROPICAL WAVES... A tropical wave axis along 85W and north of 05N is moving westward at 10-15 kt. This wave remains embedded in a very moist and unstable environment as indicated in the TPW satellite animation. Scattered moderate to strong convection is within 180 nm west of the wave axis from 07N to 09N. Scattered moderate convection is within 120 nm east of the wave axis from 06N to 10N. A tropical wave with axis extending along 105W from 04N to 17N is moving westward at 15-20 kt. This wave also remains embedded in a broad area of deep moisture within an unstable atmospheric environment. Scattered moderate to isolated strong convection is within 180 nm west and within 120 nm east of the wave axis from 08N to 10N. A tropical wave with a northeast to southwest tilted axis that extends from near 05N127W to 13N126W and to 17N123W is also moving westward at 15 to 20 kt. Deep convection in the form of scattered moderate to isolated strong convection has increased during the day within 120 nm west of the wave axis from 10N to 13N and also within 120 nm east of the wave axis from 13N to 17N. Environmental conditions are forecast to become more conducive for tropical cyclone development during the next few days, and a tropical depression could form later this week while this system moves west-northwestward around 13 kt. Please see the latest eastern North Pacific Tropical Weather Outlook for more information. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from a 1007 mb low over northern Colombia near 10N75W westward to 10N88W to 11N101W to 10N109W and northwestward to 15N116W, then southwestward 12N126W and westward to 10N132W to 11N140W. Scattered moderate to strong convection is within 180 nm south of the trough between 79W and 81w, within 120 nm south of the trough between 94W and 101W and between 108W and 110W. Scattered moderate to isolated strong convection is within 60 nm of the trough between 128W and 130W. Scattered moderate convection is 30 nm of a line from 09N110W to 09N114W, and within 30 nm of the trough west of 137W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... See the Special Features section above for more information about Tropical Storm Henriette. The pressure gradient between high pressure ridging west of Baja California and the climatological trough over and near the Baja California Peninsula is allowing for moderate northwest winds to continue over the Baja California offshore waters. Little change is expected in the present conditions through the rest of the week as high pressure remains west-northwest of the region. Fresh to locally strong northerly winds will pulse across the Gulf of Tehuantepec through Tue night as weak high pressure over the central Gulf of Mexico supports a modest pressure gradient across southern Mexico. Wind speeds will diminish beginning mid-week as the ridge weakens north of the region. Looking ahead, expect strengthening southeast winds to develop over the northern Gulf of California on Fri as a low pressure trough deepens near Baja California. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Scatterometer data passed showed mostly fresh northeast to east winds funneling across the Gulf of Papagayo region, with some small pockets of strong winds. The pressure gradient across the western Caribbean Sea and Central America will continue to support fresh to occasionally strong northeast to east winds to pulse across the Gulf of Papagayo through Tue night. Wave heights to 9 ft this morning downstream of the Gulf have lowered to around 7 ft this afternoon. Winds across the Gulf of Papagayo will diminish to fresh speeds Wed, to moderate speeds Thu and to gentle to moderate speeds Fri. Altimeter data passes from this afternoon continue to show that the southerly swell over the southern waters is in the process of decaying as wave heights there are in the range of 7 to 8 ft, mainly between the Galapagos Islands and Ecuador. REMAINDER OF THE AREA... Please refer to the Tropical Waves section above for more information regarding potential tropical cyclone development this week associated with the tropical wave that is along a position from 05N127W to 13N126W and to 17N123W. Moderate to fresh trade winds are evident roughly from about 12N to 23N and west of 120W according to the latest scatterometer data passes. Recent altimeter data passes over his region indicate seas are running 7-9 ft within this area of trades. Little change is expected over the next couple days as the pressure gradient remains nearly steady between the monsoon trough and high pressure centered north of the region. Another area of fresh winds is noted south of the monsoon trough between 120W and 130W near an active tropical wave. Mixed southeast and southwest swell is maintaining 8 to 9 ft seas south of the equator per latest altimeter data passes. This swell will gradually decay over the next couple days, allowing wave heights in this area to subside below 8 ft by Tue night. $$ Aguirre