Tropical Weather Discussion
Issued by NWS
AXPZ20 KNHC 230946
Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1005 UTC Sun Apr 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
Based on 0600 UTC surface analysis and satellite imagery through
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
Scatterometer winds indicate that the ITCZ forms at 05N85W and
extends nw through an embedded n to s orientated trough at
07N123W, then turns sw to beyond 03N140W. Scattered moderate
isolated strong convection is noted within 90 nm either side of
a line from 05N85W to 05N103W, within 120 nm either side of a
line from 07N120W to 05N128W and within 75 nm either side of a
line from 03N137W to 03N140W.
OFFSHORE WATERS WITHIN 250 NM OF MEXICO...
A weakening cold front is approaching 32N120W and is bridged by
a surface ridge that is meandering from near 23N116W to 12N94W.
Gentle to locally moderate northwesterly winds are observed
across the waters s of 27N, with 5 to 8 ft seas primarily due to
long period nw swell. The swells will continue to subside today,
with seas of 4 to 7 ft tonight. A tightening pressure gradient
is already supporting a moderate to fresh nw breeze across the
EPAC waters n of 27N. Expect fresh to strong nw winds, and seas
of 8 to 12 ft, from 30N to 32N this afternoon through Mon night.
These conditions will spread s on Tue and reach as far s as 26N
on Tue night. Strong to near gale force northwesterly winds
expected n of 29N late Wed night through Fri night with combined
seas of 11 to 16 ft.
Gulf of California: Variable winds are setting up around a weak
surface low that will develop n of 30N today, where it will
meander through mid week with a trough extending s across the
Baja California Peninsula. Fresh to strong nocturnal sw winds
are expected each night across the gulf waters from 29.5N to
31N, with seas building to about 5 ft.
Gulf of Tehuantepec: Moderate to fresh northerly drainage flow
expected at sunrise this morning then increasing to a fresh to
locally strong n breeze by this afternoon. The n flow will
strengthen tonight to near gale force by Mon morning, with seas
building to 11 ft downstream of the gulf near 14.5N95W around
sunrise on Mon. The pressure gradient will quickly relax on Mon
with winds less than 20 kt and seas less than 8 ft on Mon night.
OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND
WITHIN 750 NM OF ECUADOR...
Light to gentle winds mostly onshore flow expected during the
day becoming offshore along the coasts at night. Combined seas
of 3 to 5 ft in mixed SW and NW swell forecast during the next
REMAINDER OF THE AREA...
A cold front currently along 32N122W to 25N140W will lose
identity tonight to the s of 30N, but continue e to the n of
30N. Expect nw swell, in the form of 7 to 9 ft seas, to
propagate e across the waters w of 110W today, then subside from
the nw early this week. Strong nw winds and seas of 8 to 12 ft
expected n of 29.5N e of 123W tonight through early Wed, with
similar conditions n of 28n e of 126W on Thu night.