AXPZ20 KNHC 291000

1005 UTC SUN MAY 29 2016

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 0830 UTC.


A tropical wave is along 81W/82W from 12N southward, moving westward 10 to 15 knots. Convective precipitation: scattered to numerous strong from 04N to 06N between 77W and 80W.


The monsoon trough passes through 10N85W to a 1010 mb low pressure center that is near 09N93W, to 13N109W, to a 1010 mb low pressure center that is near 11N121W, and to 08N127W. The ITCZ continues from 08N127W to 07N135W, and beyond 06N140W. Convective precipitation: scattered moderate to isolated strong within 270 nm to the south of the monsoon trough between 94W and 107W, and within 150 nm to the south of the monsoon trough between 116W and 120W. Numerous strong within 60 NM to the south of the ITCZ between 137W and 139W.

A 1010 mb low pressure center is near 11N121W. Convective precipitation...numerous strong within 90 nm to the north and northwest of the monsoon trough and the 1010 mb low pressure center, between 119w and 124w.


A surface ridge is along 23N117W to 26N130W beyond 32N135W. Surface high pressure covers the eastern Pacific Ocean from 17N northward from 116W westward. ASCAT winds have been showing fresh north to northeast winds from the ITCZ to 22N from 118W westward. Gale-force northerly winds that are to the north of the area near the California coast are expected to produce an area sea heights of 8 feet to 9 feet. The 8 foot to 9 foot sea heights are forecast to reach as far as 28N between 122W and 129W during the next few days.

A 1008 mb low pressure center is near 11N122W. The latest scatterometer data from 29/0500 utc showed 20 to 25 knot wind speeds near the low center. The consensus of the global models showed that the low center was going to be surrounded by 20 to 25 knot wind speeds and 8 to 10 foot sea heights for the first 24 hours of the 48-hour forecast period. The wind speeds are forecast to weaken to 20 knots or less for day two. The sea heights continue to range from 8 feet to 9 feet, mostly in the vicinity of the low center. Yesterday's forecast showed that the cross-equatorial swell was going to envelop and include the area of the low pressure center. Today's forecast keeps 8 foot to 10 foot swells separate for the low center separate from the areas of the cross-equatorial swell.

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