000 AXPZ20 KNHC 231617 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Sat Jun 23 2018 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. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 10N75W TO 10N93W to a 1010 mb low pressure near 14.5N105W to a 1007 mb low pressure near 12.5N116W to 09N122W. The ITCZ continues from 09N122W to 08N130W to 10N140W. Scattered to locally numerous moderate to strong convection noted within 240 nm of the coasts from Nicaragua to Colombia. Otherwise, scattered moderate to strong convection is from 04N to 09N between 91W and 100W, from 08N to 18N between 99W and 110W, from 09N to 14N between 112W and 120W and from 07N to 15N W of 130W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... NW winds have diminished early this morning across the waters west of Baja California, as a broad surface trough along the W coast of the peninsula shifts westward across the NE Pacific waters. Winds west of the peninsula will become variable less than 15 kt through the weekend. However, southerly winds inside the Gulf of California have increased quickly overnight, and are forecast at 20-30 kt to the north of 30N this morning, and fresh to strong elsewhere N of 26N this morning. Seas across this area will increase to 6-9 ft later this morning through afternoon, before winds and seas begin to slowly subside through late Sunday. Further south, long period cross-equatorial SW swell has moved into the regional waters overnight and will affect the waters from central Baja California to Central America through Monday. 5 to 7 ft seas off of Southern Mexico this morning will build to 6-8 ft by Sun morning before slowly subsiding late Sun night and Mon. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... The monsoon trough will meander between 09N and 13N the next several days. Light to gentle winds will prevail north of the monsoon trough, with gentle to moderate S to SW winds expected south of the trough axis. Long period cross-equatorial SW swell is across southern forecast waters with seas to 8 ft. The swell will propagate further north to the offshore waters of Costa Rica and Colombia today and then will gradually subside through Sun. REMAINDER OF THE AREA... High pressure north of the area centered near 36N141W extends a ridge SE to near the Revillagigedo Islands. Moderate to fresh NE to E winds prevail west of 130W with seas generally ranging between 5 to 7 ft. Gentle to moderate N to NE winds dominate the remainder of the basin north of the monsoon trough and west of 120W. The high pressure center is forecast to shift NW and reorganize, which will freshen winds N of 25N and to the west of 125W through Mon. Typical northerly swell generated offshore of California is propagating into the northern waters this morning, and will build seas modestly to 8 ft north of 28.5N between 122W and 129W late tonight before seas subside to 6-7 ft Sun afternoon. The cross-equatorial southerly swell is also moving through the tropical waters south of 20N and west of 120W this morning, and will maintain seas 5-7 ft there through Mon. A low pressure centered near 12.5N116W and embedded along the monsoon trough has an estimated pressure of 1007 mb. Model guidance shows this low emerging from the trough and drifting northward with a gradual increase in intensity through the weekend. Active thunderstorms will continue in the vicinity of this low through early next week before the low moves across cooler waters and begins to weaken considerably late Tue. A 1010 mb low pressure is near 14.5N105W generating scattered moderate convection from 09N to 18N between 98W and 110W. Global models guidance indicate there is a good chance for this low to develop into a tropical cyclone SW of Mexico early next week. $$ Stripling