Tropical Weather Discussion
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AXPZ20 KNHC 271454

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1455 UTC Thu Jul 27 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 1200 UTC surface analysis and satellite imagery through
1500 UTC.

Hurricane Hilary is centered near 17.6N 116.0W at 27/1500 UTC or
about 470 nm SW of the southern tip of Baja California moving
WNW at 9 kt. Estimated minimum central pressure is 986 mb.
Maximum sustained wind speed is 70 kt with gusts to 85 kt.
Numerous moderate and scattered strong convection is from 17N to
19N between 113W and 116W. Scattered moderate convection is
elsewhere from 15N to 20N between 110W and 118W. See latest NHC
forecast/advisory under AWIPS/WMO headers MIATCMEP4/WTPZ24 for
more details.

Tropical Storm Irwin is centered near 15.0N 124.2W at 27/1500
UTC or about 935 nm WSW of the southern tip of Baja California
moving W at 2 kt. Estimated minimum central pressure is 1000 mb.
Maximum sustained wind speed is 50 kt with gusts to 60 kt.
Numerous moderate and scattered strong convection is within 105
nm of center. Scattered moderate convection is elsewhere from 13N
to 17N between 123W and 127W. See latest NHC forecast/ advisory
under AWIPS/WMO headers MIATCMEP5/WTPZ25 for more details.


The monsoon trough extends from 08N79W TO 08N98W TO 12N109W.
The ITCZ extends from 10N130W to 07N140W. Scattered moderate
convection is from 03N to 08N E of 81W...from 06N to 11N between
93W and 98W...from 05N to 14N between 101W and 115W...and from
06N to 11N between 130W and 139W.


Gentle to moderate NW winds are expected to continue within 120
nm of the Baja California peninsula through Friday. Seas will
remain 6 to 8 ft as southerly swell associated with Hurricane
Hilary will continue impacting the forecast zones offshore of
Baja California through Friday then shift W of the area this
weekend. Thereafter southern hemisphere southerly swell will
impact the Mexico coastline reaching 29N by Monday with seas
reaching 8 to 9 ft generally W of 105W.

Nocturnal fresh northerly winds are forecast across the Gulf of
Tehuantepec through Friday morning with seas peaking around 8 ft
during each period of strongest winds. Hilary will pass SW of
Clarion Island today, in the extreme SW waters of marine zone
PMZ015. Marine conditions will steadily improve SW of Baja
California through Fri night.

Across the Gulf of Papagayo, expect fresh winds each night with
the assistance of the nocturnal drainage flow the next few days,
occasionally building maximum seas 7 to 8 ft in a mix of E wind
waves and long period SW swell.

Gentle to moderate S to SW winds are expected the next few days.
Long period cross-equatorial SW swell will continue to propagate
into the forecast waters through Saturday, reaching the waters
between Ecuador and the Galapagos Islands tonight with building
seas of 8-9 ft.

High pressure is located N of the area with a ridge axis
extending across the forecast waters N of 23N. The pressure
gradient between this system and the active zone of tropical
cyclone activity will maintain moderate to fresh N to NE winds W
of 120W through Saturday. Long period cross equatorial SW swell
of 8-9 ft will spread across the waters S of 10N and E of 110W,
persisting into the weekend.

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