000 AXPZ20 KNHC 042143 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1924 UTC Thu Aug 4 2016 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... Tropical Storm Ivette is centered near 14.7N 127.3W at 04/2100 UTC, moving W or 270 degrees at 12 kt. Estimated minimum central pressure is 1002 mb, and maximum sustained winds are now near 45 kt with gusts to 55 kt based on a recent scatterometer pass. Vertical shear over Ivette is gradually decreasing, and the low- level center is now embedded beneath a persistent CDO feature. The official intensity forecast calls for Ivette to reach minimal hurricane strenght on Saturday. Ivette is moving toward the west and this motion is expected to continue through Friday. A west- northwestward motion with a decrease in forward speed is expected Friday night and Saturday. See latest NHC forecast/advisory under AWIPS/WMO headers MIATCMEP5/WTPZ25 KNHC for more details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A monsoon trough extends from 11N102W TO 09N112W. The ITCZ axis extends from 10N130W to 09N135W to 11N140W. Scattered moderate convection is noted from 07N to 09N between 107W and 109W, and within 90 NM N of trough between 113 W and 116W. Similar convection is within 150 NM south of axis W of 130W. ...DISCUSSION... N of 15N E of 120W: Weak surface troughing will persist along the Baja California peninsula through the weekend. Light to moderate S winds will prevail across the north central Gulf of California the next few days. In the Gulf of Tehuantepec, mainly fresh N winds are noted this afternoon. Winds are forecast to become variable tonight and will blow from the SE on Wed in association with an area of disturbed weather that has formed near and to the south of the Gulf of Tehuantepec. A surface trough is analyzed from 15N93W to 12N94W on the 1800 UTC surface map. Most of the convection associated with this trough is S of 15N. This disturbance is expected to move west-northwestward and merge with the remnants of Atlantic Tropical Storm Earl, and an area of low pressure is forecast to form near the southwestern coast of Mexico over the weekend. Conditions appear conducive for development, and a tropical depression is likely to form early next week while the low moves northwestward toward the Baja California peninsula. Earl is still a heavy rainfall threat as it weakens over nothern Guatemala and SE Mexico. It is expected to produce total rainfall accumulations of 8 to 12 inches over portions of Belize, Guatemala, and the Mexican states of Campeche, Chiapas, Quintana Roo, Tabasco and Veracruz through Friday morning. Heavy rain associated with widespread showers and thunderstorms occurring ahead of Earl will shift westward through the weekend, and could produce torrential rainfall across portions of the area from Tehuantepec to Jalisco Mexico by Sunday evening. Please refer to the latest bulletins and advisories from your local weather agencies. S of 15N E of 120W: East of 100W, moderate WSW monsoonal winds are expected through Friday as Earl moves across central America. Active weather is expected to continue across the tropical eastern Pacific and central America through Saturday. Torrential rainfall and flash flooding will be possible across the mountainous interior of the area during this time. See the latest bulletins and advisories from your local weather agencies. Long-period cross-equatorial SW swell will produce 4-7 ft seas across the region the next few days. W of 120W: Post Tropical Storm Howard is centered near 22N140W with an estimated minimum central pressure of 1011 mb. 20-30 kt winds are expected over forecast waters from 22N to 28N W of 137W. Some moderate convection persists north of the low center. Howard will continue to move west during the next 24 hours and weaken very slowly, with associated winds and seas moving west of 140W by 24 hours. Ridging extending into the region from NW of the area is maintaining moderate to occasionally fresh NE to E winds. Fresh to strong NE winds offshore of California will generate fresh N swell that will move into the northern waters. Seas to 8 ft will propagate southward but remain N of 30N through Sunday. $$ GR