AXPZ20 KNHC 220315
Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0405 UTC Fri Jun 22 2018
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 0000 UTC surface analysis and satellite imagery through
A tropical wave axis extending from 17N99W to 04N101W is moving
west at 15 kt. Scattered moderate isolated strong convection is
from 07N to 13N between 97W and 106W. An area of low pressure is
expected to develop from this system by early next week, and a
tropical cyclone may eventually develop from this feature south
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
The monsoon trough extends from coast of Costa Rica near 10N86W
to 14N107W to 1011 mb low pressure near 13N106W to 08N122W. The
ITCZ continues from 08N122W to 10N138W. Scattered moderate
convection is within 120 nm either side of the convergence zone
axis west of 114W.
OFFSHORE WATERS WITHIN 250 NM OF MEXICO...
Moderate NW winds west of Baja California will diminish today
through Sat night, and a broad surface trough will prevail along
the length of the peninsula through Sun morning. Southerly winds
will increase east of the trough axis in the Gulf of California
this weekend, becoming fresh to strong southeasterly N of 29N
Sat afternoon, continuing into early Sun morning. Seas in the
northern Gulf of California to build to 6-8 ft by Sat night,
then subside Sun along with a decrease in surface winds. Long
period cross-equatorial SW swell will reach the waters off
Southern Mexico Fri afternoon, and build seas to near 7 ft in
offshore waters by Sat. Seas will subside there Sun and Mon.
OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND
WITHIN 750 NM OF ECUADOR...
The monsoon trough will meander between 09N and 11N the next
several days. Light to gentle winds will prevail north of the
monsoon trough, with gentle to moderate S to SW winds expected
south of the trough axis. Long period cross-equatorial SW swell
will spread across southern forecast waters, with seas building
to around 8 ft S of 08N by early Sat, then gradually subside on
Sun and Mon.
REMAINDER OF THE AREA... Low pressure centered near 13N116W is
embedded in the monsoon trough with an estimated pressure of
1011 mb. Model guidance shows the low emerging from the trough
and drifting northward with a gradual increase in intensity
through the weekend. The GFS is much more aggressive with this
low than other global models, and is an outlier at this point.
However, this low merits close observation over the next few
days for signs of increased organization.
A trough is analyzed from 14N137W to 07N140W. Scattered moderate
convection is associated with this feature. Seas to 8 ft are
evident near the trough axis in latest altimeter sea state data.
The trough will drift westward, and move west of 140W Fri night.
Elsewhere, high pressure centered near well north of the area
extends a ridge SE to near the Revillagigedo Islands. Gentle to
moderate trades prevail west of 120W, and light to gentle winds
dominate the remainder of the basin based on ASCAT data. A pulse
of northerly swell will propagate into the northern waters with
seas building to 6 to 9 ft north of 25N between 120W and 130W on
Fri. Cross-equatorial southerly swell will build seas to 6 to 9
ft south of 10N and west of 90W late Friday.