Tropical Weather Discussion
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AXPZ20 KNHC 232153

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
2021 UTC Tue May 23 2017

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
2145 UTC.


The monsoon trough axis extends from 10N86W to 12N100W to
08N114W TO 08N121W. The intertropical convergence zone axis
extends from 08N121W to 07N140W. Scattered moderate and isolated
strong convection is within 150 nm on either side of the monsoon
trough. Isolated moderate convection prevails within 100 nm on
either side of the ITCZ.



A weak pressure gradient prevails across the area supporting
moderate NW winds prevailing across the Baja peninsula waters,
and light NW to W winds from Las Tres Marias to Acapulco. Seas
of 4 to 6 ft in mixed NW and SW swell and will subside to 4 to 5
ft by tonight. The pressure gradient will tighten somewhat N of
20N Wednesday through Friday as the ridge builds modestly into
the region, with winds and seas increasing slightly.

In the Gulf of California, mainly light and variable winds are
expected through Thursday, with seas of 2 ft or less, except 3 to
4 ft near the entrance. Low pressure will deepen just N of the
area over SW Arizona by Wednesday night through the end of the
week. A trough will extend from the low across the northern Gulf
to Baja California Norte. Fresh to strong southerly winds will
develop SE of the trough Wednesday night, and then again on
Thursday night as winds become enhanced through the gaps in the
higher terrain of Baja. Seas will increase significantly,
reaching 6 to 7 ft each night during the nocturnal wind max.

S of 16N including the Gulf of Tehuantepec, broad and weak low
pressure has persisted across the offshore waters SW of
Tehuantepec the past few days, drifting to the W. Gentle to
moderate SE winds occurring between Tehuantepec and offshore of
Acapulco will gradually weaken and veer SW through Wednesday.


Moderate to fresh SE winds prevail between the Papagayo region
and Tehuantepec, with seas of 5 to 7 ft in SW swell. Expect these
conditions to continue today before gentle to moderate SW to W
monsoonal winds spread N of 09N and into the coastal waters
tonight into early Wednesday. Nocturnal offshore winds will pulse
to fresh levels near the Gulf of Papagayo by Saturday night.
Moderate SW winds are expected S of 09N through Thursday night,
with seas subsiding through Wednesday before a new pulse of SW
swell arrives Thursday through late Friday. Otherwise, little
change is anticipated through the upcoming weekend.


A weak ridge extends from 30N140W SE to near 12N110W. The ridge
will drift by Wednesday as a weak front or trough moves SE
across the waters N of 30N by early Wednesday, accompanied by
long period NW swell. This will build seas to 6 to 8 ft from 30N
to 32N between 120W and 135W. Elsewhere N of the convergence
zone, the weak ridge will maintain moderate trade winds S of 18N,
with seas of 5 to 7 ft expected. Little change is anticipated
through the upcoming weekend.


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