000 AXPZ20 KNHC 280903 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 450 UTC Tue May 28 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 0600 UTC surface analysis and satellite imagery through 0900 UTC. ...SPECIAL FEATURES... ...Heavy Rainfall Potential Over Central America... A large low level cyclonic circulation that is typical for this time of the year, called a Central American Gyre, is forecast to persist across the far eastern tropical Pacific and Central America for the next several days. Abundant moisture and increasing instability are expected through Wed, which could lead to a very significant rainfall event over portions of Central America. Life-threatening flash flooding and mudslides will be possible in areas of mountainous terrain. Please refer to your local meteorological service for more details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 11N86W to 09N90W to 13.5N101W to 09N110W to 09N126W to 07N131W. The ITCZ extends from 07N131W to 07N140W. Scattered moderate to isolated strong convection is noted from 04N to 13N between 84W and 97W. Scattered moderate isolated strong convection was noted from 05N to 10N between 100W and 110W. Scattered moderate convection was noted from 05N to 10N between 120W and 140W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A ridge extends across the forecast waters west of the Baja California peninsula. Overnight surface observations indicate fresh to strong winds, with seas of 6-8 ft prevail west of the Baja California peninsula. Light to gentle winds, with seas in the 4-6 ft range prevail elsewhere over the open waters off Mexico. Light winds and seas 2 ft or less prevail over the Gulf of California. High pressure will weaken slightly by Wed. This will diminish winds to 20 kt or less west of the Baja California peninsula, with seas subsiding below 8 ft. SW winds will strengthen south of the Gulf of Tehunatepec by midweek. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Please see the Special Features section for more information about the Central American Gyre, which will continue to bring locally heavy rains to parts of Central America and the adjacent offshore waters through at least mid week. Latest surface observations indicate moderate to fresh S to SW winds S of the monsoon trough, with seas in the 6-8 ft range. Moderate to locally fresh winds, and seas of 5-6 ft prevail N of the monsoon trough. Low pressure of 1010 mb embedded within the broad gyre is centered offshore the coast of Nicaragua. The monsoon trough will lift northward by midweek, with the low pressure likely moving inland over Central America by midweek. The southerly monsoon flow is forecast to strengthen to 20-25 kt by Wed. Seas will also build to 8-12 ft by mid week as locally generated wind waves in the enhanced monsoon flow combines with cross equatorial SW swell. REMAINDER OF THE AREA... High pressure of 1029 mb centered near 33N138W extends a ridge SE to near the Revillagigedo Islands. The pressure gradient between the ridge and lower pressure in the vicinity of the ITCZ is supporting moderate to fresh NE winds across much of the area north of the ITCZ and west of 120W. Moderate to fresh winds will continue to prevail over this area the next several days. Long period cross equatorial SW swell will continue to dominate much of the forecast waters. Seas 8 ft or greater cover the waters south of 11N between 92W and 130W. Seas will slowly subside the next couple of days, with areal coverage of seas 8 ft or greater decreasing. $$ AL