000
AXPZ20 KNHC 291655
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 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 1200 UTC surface analysis and satellite imagery through
1430 UTC.

...TROPICAL WAVES...

A tropical wave is along 82W, moving westward at 10 to 15 knots.
Scattered to numerous strong convection is present from 03N to
07N between 77W and 81W.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...

The monsoon trough passes through 11N86W to a 1010 mb low
pressure center near 10N95W, to 09N100W, to 13N115W, to a 1010
mb low pressure center near 11N121W, and to 10N125W. The ITCZ
continues from 10N125W to 08N131W, and to 06N140W. Scattered
moderate to isolated strong convection is found from 06N to 13N
between 100W and 108W. Scattered moderate convection is located
from 04N to 07N between 138W and 140W.

A 1010 mb low pressure center is near 11N121W. Numerous strong
convection exists within 120 nm nw and se of the monsoon trough
between 118W and 125W.

...DISCUSSION... 

Northerly winds are continuing to the north of the area along
the California coast as a cold front moves inland. Latest ASCAT
imagery shows fresh to strong north winds from 33N to 42N east
of 128W. Latest altimetry shows an area of combined seas between
8 and 11 feet just to the north of the forecast area. As the
cold front moves farther inland...winds and seas will subside.
North swell will maintain sea heights of 8 to 9 feet north of
27N between 122W and 128W today. Seas are expected to subside
below 8 feet tonight. Winds and seas will continue to subside
north of 23N through Tuesday night.

A surface ridge extends northwestward from 21N119W to beyond
32N137W. Surface high pressure covers the eastern Pacific Ocean
from 16N northward from 115W westward. Latest ASCAT winds
generally show light to moderate north to northeast winds north
of the the ITCZ and monsoon trough to 22N from 118W westward.                                   

A 1010 mb low pressure center is near 11N121W. The latest
scatterometer data from 29/0500 utc showed 20 to 25 knot wind
speeds near the low center. Model guidance quickly weakens the
low. Convection associated with the low has begun to decrease.
Maintained 20 to 25 knot winds in the vicinity of the low in the
forecast for the next 6 hours. After 6 hours the area of seas
associated with the low merges with the area of seas associated
with southern hemisphere swell. After this low weakens...model
guidance does not develop any areas of fresh to moderate winds
in the vicinity of the trough through Friday. 

Latest altimetry showed 10 to 12 foot seas associated with long
period S to SW swell beginning to arrive from the southern
hemisphere. The only model capturing these sea heights well was
the European model. Accordingly...the latest wave height
forecast for the eastern Pacific during the next 48 hours
heavily favors European model guidance. All of the forecast
models agree that the long period swell have begun to decay and
that seas across the basin will subside below 8 ft by Thursday
evening.

$$
McElroy