AXPZ20 KNHC 272134

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
2205 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 1800 UTC surface analysis and satellite imagery through 2100 UTC.


Hurricane Hilary is centered near 17.9N 116.6W at 27/2100 UTC or about 480 nm SW of the southern tip of Baja California moving WNW at 8 kt. Estimated minimum central pressure is 989 mb. Hilary is a minimal hurricane with maximum sustained wind speed of 65 kt with gusts to 80 kt. Gradual weakening is forecast through Friday. Numerous moderate convection is within 60 nm SW quadrant. Scattered moderate convection is elsewhere from 15N to 20N between 113W and 118W. See latest NHC forecast/advisory under AWIPS/WMO headers MIATCMEP4/WTPZ24 for more details.

Tropical Storm Irwin is centered near 14.9N 124.3W at 27/2100 UTC or about 945 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. Some fluctuations in intensity are likely the rest of today and tomorrow. Numerous moderate and scattered strong convection is within 120 nm south semicircle of center. Scattered moderate convection is elsewhere from 13N to 16N between 123W and 127W. See latest NHC forecast/ advisory under AWIPS/WMO headers MIATCMEP5/WTPZ25 for more details.


The monsoon trough extends from 09N84W to 08N90W to 09N100W to 12N110W. The ITCZ extends from 10N132W to 07N140W. Scattered moderate convection is from 07N to 13N between 87W and 100W, from 07N to 15N between 100W and 111W, and from 06N to 10N W of 131W.


OFFSHORE WATERS WITHIN 250 NM OF MEXICO... 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. Cross equatorial long period southerly swell will reach the area between Los Cabos and Cabo Corrientes early on Friday, then propagate into the southern Gulf of California by Friday night, and along the coast of Baja California on Saturday.

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 is currently located SW of Clarion Island. Marine conditions will steadily improve SW of Los Cabos through Fri night.

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 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.

REMAINDER OF THE AREA... High pressure is located N of the area with a ridge axis extending across the northern forecast waters N of 20N. 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.

$$ GR