AXPZ20 KNHC 222156

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
2205 UTC Fri Jun 22 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 1800 UTC surface analysis and satellite imagery through 2100 UTC.


A tropical wave along 101W/102W is moving west at 10 kt and has slowed its forward progress today. The wave is presently moving through a moist and unstable environment. Scattered moderate to strong convection associated with this wave is located from 06N to 16N between 97W and 105W. Global models show an area of low pressure develop from this wave along 106W this weekend. This area will be monitored for potential tropical cyclone development SW of Mexico early next week.


The monsoon trough extends from 09N71W TO 07.5N79W TO 13.5N101W to 1011 mb low pressure near 13N116W TO 09N121W. The ITCZ continues from 09N121W TO 07N127W TO 10N140W. Scattered moderate to strong convection is noted from 05.5N to 15.5N between 84W and 102W, from 09N to 14N between 102W and 119W, and from 06N to 13N to the west of 133W.



Moderate NW winds are expected to prevail across the waters west of Baja California through early Sat before beginning to gradually diminish through the weekend, as a broad surface trough extending the full length of the peninsula shifts slowly westward across the Pacific waters. Winds west of the peninsula will become variable less than 15 kt through the weekend. Meanwhile, southerly winds will increase east of the trough axis inside the Gulf of California this weekend, becoming fresh to strong southeasterly N of 27N Sat afternoon, continuing into early Sun morning. Seas in the northern Gulf of California will build to 6-9 ft by Sat afternoon and evening, then subside Sun along with a decrease in surface winds.

Further south, long period cross-equatorial SW swell will begin to reach the waters off Southern Mexico this afternoon, and build seas to 5-6 ft tonight, and reach 7-8 ft by Sun morning. Sea will then begin to subside Mon.


The monsoon trough will meander between 09N and 11N 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 will spread across southern forecast waters today, with seas building to 5-6 ft this evening, and reaching 6-8 ft Sat afternoon through Sun, before gradually subsiding Mon.


High pressure centered well north of the area near 36N136W extends a modest ridge SE to near the Revillagigedo Islands. Moderate to fresh tradewinds prevail S of 27N and west of 125W, where seas are generally 6 to 8 ft, while light to gentle winds dominate the remainder of the basin westward of 110W.

Tradewinds will diminish slightly across western portions of the area this afternoon through Sat as a trough along 142W shifts well west of the area. Seas are currently 8 to 9 ft in mixed NE and NW in this area, from 10N to 15N to the west of 137W and will gradually subside to 6-7 ft through Sat. A pulse of northerly swell will propagate into the northern waters with seas building to 6 to 9 ft north of 25N between 120W and 130W early Sat. Cross-equatorial southerly swell will build seas to 6 to 9 ft south of 10N and west of 90W late tonight and continue through Sunday evening.

Low pressure centered near 13N116W is embedded along the monsoon trough with an estimated pressure of 1011 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 to the east and southeast of this low through Sat.

$$ Stripling