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Eastern North Pacific Tropical Weather Discussion

AXPZ20 KNHC 252053

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
2205 UTC Tue Jul 25 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 1800 UTC surface analysis and satellite imagery through 
2045 UTC.

 Hurricane Hilary is centered near 15.5N 108.8W at 25/2100 UTC or 
about 450 nm S of the southern tip of Baja California moving WNW 
at 10 kt. Estimated minimum central pressure is 974 mb. Maximum 
sustained wind speed is 90 kt with gusts to 110 kt. Scattered to 
numerous strong convection was within 120 nm in the NW quadrant of 
the system. Scattered moderate isolated strong convection was noted 
elsewhere within 180 nm in the NW and 90 nm in the SE semicircles. 
See latest NHC forecast/ advisory under AWIPS/WMO headers 
MIATCMEP4/WTPZ24 for more details.

Hurricane Irwin is centered near 15.7N 120.1W at 25/2100 UTC or 
about 720 nm SW of the southern tip of Baja California moving W at 6 
kt. Estimated minimum central pressure is 983 mb. Maximum sustained 
wind speed is 75 kt with gusts to 90 kt. Irwin is a small cyclone 
with scattered moderate to strong convection noted within 75 nm in 
the W and 30 nm in the E semicircles. See latest NHC 
forecast/advisory under AWIPS/WMO headers MIATCMEP5/WTPZ25
for more details.

Tropical Depression Greg is centered near 16.2N 137.9W at 25/2100 UTC
or about 1030 nm E of South Point Hawaii moving WNW at 10 kt. 
Estimated minimum central pressure is 1005 mb. Maximum sustained 
winds are now 30 kt with gusts to 40 kt. Convective activity 
associated with Greg has decreased this afternoon with isolated 
moderate convection noted within 90 nm in the SW semicircle. See 
latest NHC forecast/advisory under AWIPS/WMO headers 
MIATCMEP2/WTPZ22 for more details.

...TROPICAL WAVES... A tropical wave is along 98W/99W N of 06N 
moving W at 10-15 kt.
Scattered moderate convection is from 08N to 14N between 92W and 

trough extends from 08N78W to 10N85W to 11N99W to 10N104W. Scattered 
moderate convection is from 05N to 09N E of 82W.


Gentle to moderate NW winds off the Baja California peninsula 
are expected to continue through Wednesday, as high pressure 
remains centered N-NW of the area. Seas will remain generally 4 
to 6 ft in mixed swell through Wednesday. Thereafter...Hurricane
Hilary will begin impacting the zones offshore of Baja California
through Friday with increased winds and seas through Friday 
with large southerly swell to 10 ft. Gentle southerly flow will 
prevail in the Gulf of California, and moderate southerly flow 
across the northern Gulf of California.

Nocturnal fresh northerly winds are forecast across the Gulf of 
Tehuantepec through Thursday night into Friday morning. Hilary 
is expected to impact the offshore waters beyond 200 nm off the 
coasts of Michoacan, Colima and Jalisco through tonight, then pass 
S of the Revillagigedo Islands early Wednesday. Seas of at least 8 ft 
associated with Hilary are forecast to reach the waters between 107W 
and 115W in the vicinity of Cabo San Lucas Wednesday into Thursday.

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

Gentle to moderate S to SW winds are expected across the forecast
zones the next several days. Long period cross-equatorial SW 
swell generating 5-7 ft seas will continue to propagate into the
forecast waters through mid week. Another set of cross- 
equatorial long period SW swell of 6 to 9 ft will reach the 
waters between Ecuador and the Galapagos Islands Thursday, and 
the coast of Central America on Thursday night. 

High pressure is located N of the area with a ridge axis that 
extends across the forecast waters north of 22N. The pressure 
gradient between this system and the active zone of tropical 
cyclones between 13N and 19N will maintain fresh N to NE winds W
of 130W through mid-week. By Thursday, cross equatorial SW swell
of 8 to 9 ft will spread across the waters south of 10N and east
of 110W, persisting into the weekend.