AXPZ20 KNHC 222156
Tropical Weather Discussion
NWS National Hurricane Center Miami FL
2205 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 1800 UTC surface analysis and satellite imagery through
A tropical wave along 101W/102W is moving west at 10 kt and has
slowed its forward progress today. The wave is presently moving
through a moist and unstable environment. Scattered moderate to
strong convection associated with this wave is located from 06N
to 16N between 97W and 105W. Global models show an area of low
pressure develop from this wave along 106W this weekend. This
area will be monitored for potential tropical cyclone
development SW of Mexico early next week.
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
The monsoon trough extends from 09N71W TO 07.5N79W TO 13.5N101W
to 1011 mb low pressure near 13N116W TO 09N121W. The ITCZ
continues from 09N121W TO 07N127W TO 10N140W. Scattered moderate
to strong convection is noted from 05.5N to 15.5N between 84W
and 102W, from 09N to 14N between 102W and 119W, and from 06N to
13N to the west of 133W.
OFFSHORE WATERS WITHIN 250 NM OF MEXICO...
Moderate NW winds are expected to prevail across the waters west
of Baja California through early Sat before beginning to
gradually diminish through the weekend, as a broad surface
trough extending the full length of the peninsula shifts slowly
westward across the Pacific waters. Winds west of the peninsula
will become variable less than 15 kt through the weekend.
Meanwhile, southerly winds will increase east of the trough axis
inside the Gulf of California this weekend, becoming fresh to
strong southeasterly N of 27N Sat afternoon, continuing into
early Sun morning. Seas in the northern Gulf of California will
build to 6-9 ft by Sat afternoon and evening, then subside Sun
along with a decrease in surface winds.
Further south, long period cross-equatorial SW swell will begin
to reach the waters off Southern Mexico this afternoon, and
build seas to 5-6 ft tonight, and reach 7-8 ft by Sun morning.
Sea will then begin to subside 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 today, with seas
building to 5-6 ft this evening, and reaching 6-8 ft Sat
afternoon through Sun, before gradually subsiding Mon.
REMAINDER OF THE AREA...
High pressure centered well north of the area near 36N136W
extends a modest ridge SE to near the Revillagigedo Islands.
Moderate to fresh tradewinds prevail S of 27N and west of 125W,
where seas are generally 6 to 8 ft, while light to gentle winds
dominate the remainder of the basin westward of 110W.
Tradewinds will diminish slightly across western portions of the
area this afternoon through Sat as a trough along 142W shifts
well west of the area. Seas are currently 8 to 9 ft in mixed NE
and NW in this area, from 10N to 15N to the west of 137W and
will gradually subside to 6-7 ft through Sat. 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
early Sat. Cross-equatorial southerly swell will build seas to 6
to 9 ft south of 10N and west of 90W late tonight and continue
through Sunday evening.
Low pressure centered near 13N116W is embedded along the monsoon
trough with an estimated pressure of 1011 mb. Model guidance
shows this low emerging from the trough and drifting northward
with a gradual increase in intensity through the weekend. Active
thunderstorms will continue to the east and southeast of this
low through Sat.