000 AXPZ20 KNHC 171609 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Sat Aug 17 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 1200 UTC surface analysis and satellite imagery through 1500 UTC. ...SPECIAL FEATURES... A 1010 mb low pressure center is location near 11.5N91W this morning, or about 135 nm S of the coast of Guatemala. A broad low to middle level cyclonic circulation associated with this low is supporting scattered showers and thunderstorms within about 150 nm in the NE and 240 nm across the SW semicircles, accompanied by gusty winds and heavy downpours. Some of this activity is affecting the coastal zones of El Salvador and far SE Guatemala. This low is expected to move WNW to NW over the next couple of days, and has a medium chance for tropical cyclone formation. Moisture associated with the low will continue to produce heavy rainfall to the N and NE of the low, with the potential for flash flooding from Honduras to far SE Mexico. Winds and seas will also gradually increase across the offshore waters areas from El Salvador to offshore of Mexico the next several days. Refer to the latest NHC Tropical Weather Outlook under AWIPS/WMO headers MIATWOEP/ABPZ20 KNHC for more information. ...TROPICAL WAVES... A tropical wave extends from the Gulf of Honduras SE across Panama to coastal Colombia, moving W at 10 to 15 kt. Scattered deep convection associated with this wave is occurring across the Caribbean waters while only isolated clusters are seen across the Pacific waters offshore of Costa Rica. A tropical wave is along about 110W, moving W at 10 kt. A large cluster of scattered moderate to strong convection is occurring ahead of the wave from 12N to 17.5N between 101W and 106W. A tropical wave is near 116W-117W, moving W near 10 kt. A tropical wave is near 127W-128W, moving W near 10 kt. Scattered moderate to strong convection is occurring from 14N to 17N between 124W and 128W associated with this wave. Low pressure may form along about 15N with this wave during the weekend or early next week as it moves slowly westward. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 10.5N74W TO low pres near 11.5N91W TO 14.5N127W TO 12.5N140W. Scattered moderate to strong convection is noted from 06N to 17.5N between 89W and 107W, from 07N to 17N between 111W and 128W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A broad and weak high pressure ridge extends from well NW of the region across the Baja California offshore waters, bringing gentle to moderate NW to W winds to the local waters. This ridge will generally remain in place through early next week. The pressure gradient between this ridge and low pressure over the western United States has led to stronger winds offshore of California, and have generated N swell that will propagate to northern parts of the waters offshore Baja California Norte for the first part of the weekend. Seas at times will build to around 7 ft. A low pressure trough extending along the Baja California peninsula will support locally strong S and SE winds over the northern Gulf through this morning, but gradually diminishing this afternoon and evening. Seas across the northern Gulf were around 4-5 ft at around 1200 UTC. The pressure gradient along the Pacific coast of Baja California will tighten early next week, with NW winds increasing to moderate to fresh. For the remainder of waters offshore Mexico, generally gentle winds will prevail through today. Low pressure offshore of Guatemala will shift WNW during the next few days and spread showers, thunderstorms and squalls into the waters south of the Gulf of Tehuantepec by Sun afternoon. Expect fresh to strong easterly winds with higher gusts and seas building to near 8 ft across the far southeast waters, and north of the low pressure system late Sun through Mon. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Please see the Special Features section above for details about the area of low pressure offshore of Guatemala and associated heavy coastal rainfall. Winds in the Gulf of Papagayo will become offshore and pulse to fresh Sun night, then remain moderate thereafter. Southerly swell producing seas of 5 to 7 ft will impact the Ecuador/Galapagos offshore waters and slowly decay through early next week. Otherwise, mainly moderate winds will prevail into early next week, along with seas of 4 to 6 feet. REMAINDER OF THE AREA... Moderate to fresh winds in the wake of a tropical wave now W of 140W support seas of 6 to 8 ft from 15N to 20N W of 136W. These seas will diminish during the day as the wave moves away from the area. Across the remainder of the Pacific high seas area, moderate to fresh winds prevail in the NW corner, with moderate winds or less elsewhere. Winds will diminish Sun into early next week as the pressure gradient slackens. Northerly swell N of 27N will lead to seas of 8 to 9 ft to the W of 125W through early Sun before decaying. $$ Stripling