AXPZ20 KNHC 231523
Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1310 UTC Thu May 23 2019
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 1200 UTC surface analysis and satellite imagery through
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
The monsoon trough extends across Central America to a 1009
located over Nicaragua near 12N86W to 11N100W to 08N120W. The
ITCZ continues from 08N120W to beyond 06N140W. Scattered moderate
to strong convection is noted from 09.5N to 13.5N between 85W
and 90W, and from 07N to 11N between 92W and 98W. Numerous
moderate and scattered strong convection is seen from 08N to 13N
between 98W and 102W.
OFFSHORE WATERS WITHIN 250 NM OF MEXICO...
The pressure gradient between a ridge across the offshore
forecast waters of Baja California and lower pressure over the
SW CONUS and northern Mexico is supporting moderate to fresh NW
winds off the west coast of Baja California and N of Punta
Eugenia. NW swell associated with stronger winds off the coast of
California continues to support seas of 8 to 13 ft north of Cabo
San Lazaro, with the highest seas covering the waters N of 27N
between 116W and 125W. Winds are forecast to diminish to a gentle
to moderate breeze later today while seas will gradually subside
to near 8 ft across the offshore waters W of 110W on Fri.
Gulf of California: Winds have diminished across the northern
Gulf this morning. Looking ahead, winds will increase again to
20 to 25 by Sat night ahead of a cold front approaching the
region. Then, moderate to fresh SW winds will persist through
Gulf of Tehuantepec: Fresh to strong northerly winds will pulse
across the Gulf region early Sat morning, and again early Sun
morning with the assistance of the nocturnal drainage flow. Seas
will build to 8 ft with these short-lived gap wind events.
OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND
WITHIN 750 NM OF ECUADOR...
Disorganized showers and thunderstorms along portions of the west
coast of Central America and the far eastern North Pacific are
associated with a broad area of low pressure. Earlier satellite wind
data indicated that the large circulation has moved inland over
Central America and the chance for development has decreased.
Regardless of development, locally heavy rains are likely to
continue over portions of Central America as this system remains
nearly stationary during the next few days. These rains could cause
flash flooding and mudslides in areas of mountainous terrain. The
Weather Service in Nicaragua has reported locally heavy rain
during the last 24 hours ending at 7am this morning.
Otherwise, the monsoon trough will dominate the regional pattern
into early next week. Expect generally light to gentle winds
north of the monsoon trough and moderate to fresh S to SW winds
south of the monsoon trough through the weekend. Early next
week, the global models suggest increasing winds south of the
monsoon trough likely associated with a very broad area of low
pressure over Central America and the SW Caribbean Sea. The
increasing winds will depend on how the low pressure system
described above evolves in the coming days. Seas generally will
run 8 ft or less into the weekend, then build into early next
week in response to the strengthening monsoon flow. This
weather pattern is common in this area for this time of the
REMAINDER OF THE AREA...
Northwest swell over the waters north of 20N between 110W and
135W is producing seas ranging from 8 to 13 ft across the region
with the highest seas N of 27N between 116W and 125W. This swell
event will gradually decay by Fri, with seas falling below 8 ft
Fri night into Sat.
A high pressure ridge extends from a 1033 mb high near 37N139W
east-southeastward to near the Revillagigedo Islands. The
pressure gradient between the ridge and lower pressures in the
vicinity of the ITCZ is maintaining fresh to locally strong
trades over the waters west of 135W with seas up to 10 ft based
on altimeter data.
Elsewhere, a small area of 8 ft seas in SW swell persists
roughly from 05N to 09N between 103W and 111W. Additional
pulses of cross- equatorial SW swell will result in 8 ft seas
developing over the waters S of 08N between 96W and 115W on Fri.
Another and stronger SW swell event is expected early on Sun
through early next week, reaching the coast of Mexico and Central
America Mon night into Tue.