000 AXPZ20 KNHC 150145 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 UTC Thu Aug 15 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 0130 UTC. ...SPECIAL FEATURES... A large surge of moisture will continue across Panama, Costa Rica, and southern Nicaragua through the next 24-36 hours. Environmental conditions remain highly favorable for heavy rains to continue to accumulate, with higher localized totals near strong topographical forcing. Costa Rica has received nearly 7 inches of rainfall in the last 24 hours, with 2-4" of additional rain in the last 6 hours mostly on the north Caribbean side of the country. By Friday, the focus of heavy rainfall will shift north to Nicaragua, El Salvador, southern Honduras/Guatemala and southern Chiapas Mexico. Flash flooding and mudslides will be the biggest hazard during this event. ...TROPICAL WAVES... A tropical wave has an axis extending from 08N86W to western Nicaragua, moving west around 10 kt. Scattered moderate and isolated strong convection is noted from 04N to 09N E of 88W. A tropical wave has an axis extending from 02N100W to 16N98W, moving west at around 15 kt. Scattered moderate and isolated strong convection is noted from 05N to 13N between 88W and 96W. A tropical wave has an axis extending from 06N110W to 18N109W, moving west at 15 to 20 kt. Scattered moderate and isolated strong convection is noted from 10N to 15.5N between 102W and 108W. A tropical wave has an axis extending from 04N119W to 17N118W, moving west at 15 to 20 kt. Scattered moderate and isolated strong convection is noted from 10N to 15N between 115W and 120W. A tropical wave has an axis extending from 07N137W to 16N134W, moving west at 10 kt. Scattered moderate convection is noted from 12N to 18N between 130W and 135W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from northern Colombia near 09N74W to 09N90W to 07N98W to 10N108W to 07N122W, then resumes from 18N123W to 13N134W. The ITCZ extends from 11N137W to 10N140W. Scattered moderate and isolated strong convection is noted from 08N to 10N W of 137W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A broad high pressure ridge is gradually building toward the Baja California offshore waters as the remnants of Henriette, currently centered near 22N118W, continue weakening. Earlier scatterometer data noted gentle to moderate NW winds along the Baja California coast north of Cabo San Lazaro. Altimeter data indicated that seas were generally running 4-6 ft off Baja California Sur. The ridge will support mainly gentle to moderate WNW flow through the weekend, except occasionally fresh winds offshore of Baja California Norte. Strengthening northerly winds off the California coast will produce a set of NW swell that will reach the Baja California Norte waters Fri into Sat. This will build seas to near 8 ft west of Guadalupe Island this weekend. In the Gulf of California, mainly gentle winds and seas of 3 ft or less will prevail through Thu. A deepening low pressure trough along the Baja California peninsula will support fresh to strong SE winds over the northern Gulf Fri through Sat, with seas building to around 6 ft. Fresh northerly winds will pulse across the Gulf of Tehuantepec late tonight into early Thu. Looking ahead, a broad area of low pressure may form SE to S of Chiapas Mexico this weekend, then pass S of the Gulf of Tehuantepec early next week. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Fresh to occasionally strong NE to E winds will pulse across the Gulf of Papagayo tonight, causing seas to build to between 6 and 8 ft during the strongest winds. Freshening SW monsoon flow will cause seas to build to 8 ft off the coast of Central America through Thu, with lower winds and seas thereafter. Looking ahead, broad low pressure may form offshore of Central America this weekend, shifting W-NW into early next week. REMAINDER OF THE AREA... An elongated area of low pressure near 16.5N130.5W will support fresh to strong winds and seas of 8-10 ft mainly on the NW side of this feature. This feature is forecast to shift W of 140W by early Sat. The remnant low of Henriette is analyzed near 22N118W and will continue drifting W-NW until it dissipates later tonight. No deep convection is associated with the system. Earlier scatterometer data shows moderate to fresh trades north of the monsoon trough. These trades are forecast to prevail into the first part of the weekend, then will weaken to gentle to moderate thereafter as the pressure gradient loosens. Meanwhile, seas of 4-7 ft also currently prevail across this same area. A set of northerly swell will spread S of 32N Fri through Sat, building seas to between 8 and 9 ft north of 28N between 122W and 132W. Mainly moderate SE to S winds expected to continue south of the monsoon trough for the next several days, along with 4-7 ft seas. $$ Lewitsky