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.

...SPECIAL FEATURES... 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 96W.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 08N78W to 10N85W to 11N99W to 10N104W. Scattered moderate convection is from 05N to 09N E of 82W.


OFFSHORE WATERS WITHIN 250 NM OF MEXICO... 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.

OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... 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.

REMAINDER OF THE AREA... 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.

$$ Cobb