AXPZ20 KNHC 281520

1605 UTC SAT MAY 28 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 1200 UTC surface analysis and satellite imagery through 1500 UTC.


Discontinuous monsoon trough extends from 10N84W to 12N92W, then resumes from 13N110W through a 1010 mb low near 10N122W to 07N128W. ITCZ extends from 07N128W to beyond 05N140W. Scattered moderate convection is from 06N to 14N between 84W and 100W. Scattered moderate convection within 45 nm of axis west of 135W.


High pressure centered N of the area extends a subtropical ridge over northern half of the forecast area, roughly north of 15N and west of 115W. A weak low with minimal convection is analyzed near 10N122W. Satellite imagery shows widely scattered random convective activity east of 103W between 05N-15N. Scatterometer data from last night shows an area of fresh NE winds west of 136W between 09N-12N, and moderate trades N of the convergence zone west of 125W. Mainly gentle winds prevail elsewhere across the basin. Model guidance shows the low remaining fairly weak with some development while winds and seas increase around the low through Sun night in response to a slightly better pressure gradient. But winds are expected to remain below 22-23 kt and max seas should only be around 8-9 ft within 150-180 nm of the low center. Elsewhere, near gale force N-NW winds along the California coast have produced an area of 7-8 ft N swell in north-central waters between 120W-130W. Cross-equatorial S-SW swell will affect the area S of the equator between 105W-120W. The swell will eventually merge with the area of elevated sea heights associated with the low near 10N122W to produce a fairly large area of 6-8 ft seas in south-central waters. Mostly benign marine conditions are expected to prevail across the remainder of the forecast area through Tuesday.

$$ Mundell