000 AXPZ20 KNHC 170949 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 731 UTC Thu Aug 17 2017 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 0600 UTC surface analysis and satellite imagery through 0830 UTC. ..TROPICAL WAVES... A tropical wave extends N from 11N87W to 23N85W. This wave is moving westward around 15 kt during the past 24 hours. Short term model diagnostics show subtle troughing at 700 mb in conjunction with this wave. TPW satellite imagery shows this wave is embedded in an area of deep layer moisture, but no significant convection is currently associated with this wave. A tropical wave extends from 11N105W to 18N105W. The wave has moved W around 10 kt during the past 24 hours. The wave coincides with a well defined 700 mb trough in short term model guidance. TPW satellite imagery shows this wave is embedded in an area of deep layer moisture. Scattered moderate and isolated strong convection is found from from 07N to 10N between 100W and 105W and from 16N to 19N between 105W and 108W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 10N74W to 08N81W to low pres 1008 mb near 09N86W to 12N104W to low pres 1009 mb near 12N111W to 14N125W to 12N135W to 14N140W. Scattered moderate and isolated strong convection is present from 09N to 15N between 109W and 119W and from 09N to 14N between 130W and 138W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A ridge will reside over the forecast waters west of Baja California and produce mainly gentle to moderate NW to N winds and seas in the 4-6 ft range the remainder of the week. A surface trough will meander across the Baja California Peninsula and Gulf of California through Mon night. A surface low will periodically develop over the Gulf of California N of 30N. Gulf of California...gentle southerly flow will persist across the Gulf of California through the upcoming weekend, with the exception of moderate to locally fresh winds surrounding the low over the waters N of 30N. Gulf of Tehuantepec: fresh to strong northerly winds are expected, with the assistance of the drainage flow, during the overnight and early morning hours tonight through Monday. Seas are forecast to build to 6-8 ft with these winds. On Monday, winds could increase to 30 kt and seas build 10 ft as tropical low approaches from the Caribbean. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo: fresh to strong offshore winds are expected during the overnight and early morning hours through Friday night, with moderate to fresh winds expected thereafter. Gentle NE to E winds are expected N of the monsoon trough, while moderate southerly winds are expected S of the monsoon trough axis through Mon night with 3 to 6 ft seas throughout. REMAINDER OF THE AREA... Low pressure is embedded in the monsoon trough near 12N111W. Satellite-derived wind data indicate winds of 20 to 25 kt on the east side of the low. Latest altimetry showed seas of 8 to 10 ft on the N side of the low. Environmental conditions are expected to be conducive for development of this system during the next several days. The subtropical ridge extends from 32N130W to near 25N118W. Latest satellite-derived wind data show moderate to fresh winds in the N semicircle of weak low pressure systems centered near 17N121W and near 19N134W. Otherwise, light to moderate anticyclonic flow is forecast N of the monsoon trough and W of 115W. Long period southerly swell coming from the southern hemisphere continue to subside. 7 to 8 ft seas are observed S of the Equator between 95W and 120W. These seas will subside to less than 8 ft by midday today. The next long period swell event is not expected until the middle of next week. $$ CAM