Home > Weather > Hurricane Information > Tropical East Pacific Satellite

Tropical East Pacific Satellite

NHC Tropical Weather Discussion (East Pacific)

National Hurricane Center – Tropical Weather Discussion (East Pacific)

NHC East Pacific Tropical Weather Discussion

AXPZ20 KNHC 160358
TWDEP Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0405 UTC Sun Dec 16 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
meteorological analysis.

Based on 0000 UTC surface analysis and satellite imagery through 0330 UTC.


Gulf of Tehuantepec Gale Warning: The tight pressure gradient
over southeastern Mexico resulting from the combination of strong
high pressure over northern Mexico and lower pressure south of Mexico is bringing strong gale force northerly winds over the Gulf of Tehuantepec with seas to 18 ft. This strong gap wind event will continue through Sun night, before diminishing on Mon as the strong high pressure over Mexico shifts eastward and weakens. Seas with this event will subside to 9 to 13 ft Mon and to less than 8 ft on Tue as the northerly winds diminish to fresh speeds. Please refer to the latest high seas forecast issued under AWIPS/WMO headers HSFEP2/FZPN03 for more specific marine related details. …INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH…

The monsoon trough axis extends from 08N78W to 08N84W to 06N90W, where latest scatterometer data indicated that it transitions to the ITCZ and continues to 04N100W to 06N115W to 09N130W to 08N140W. Scattered moderate convection is noted from 08N to 18N W of 119W.


OFFSHORE WATERS WITHIN 250 NM OF MEXICO… A weak ridge will preavil over the area maintaining light to gentle breezes across the area. Northwest swell with seas to 9 ft will persist in the offshore waters of Baja California through Sun. A cold front will approach the region Mon bringing a new set of northwest swell, with seas from 12 to 17 ft reaching the northern coast of Baja California Norte and Guadalupe Island. Swell of 12 to 15 ft will cover the Baja offshore waters to the Revillagigedo Islands into mid week. Swell of this size and period will present hazardous seas for mariners, cause very powerful and dangerous surf along the Pacific reefs and beaches, and likely produce areas of modest coastal flooding and beach erosion.

Over the Gulf of California, strong high pressure north of region
have been supporting moderate to fresh breezes across the basin.

A mid to upper-level disturbance approaching the area from the west may bring a few showers to the central and southern portions of the Baja California Peninsula and Gulf of California through Sun. Strong high pressure will build N of the area by the middle of the week and will support fresh to strong winds across the northern and central gulf.

OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR… Gulf of Papagayo…Fresh to strong gap winds will pulse starting
tonight and persist into early next week as high pressure builds north of the area. The gap winds will diminish late Tue night. Seas with these winds are expected to be 8 to 9 ft. Fresh winds will also pulse across the Gulf of Panama and Gulf of Fonseca tonight and Sun. Elsewhere, gentle to moderate winds will persist on either side of the monsoon trough through early next week, as seas remain in the 4 to 6 ft range.

REMAINDER OF THE AREA… A mid to upper-level trough north of about 18N between 115W and 134W is supporting scattered moderate convection over the northern waters. Seas are as high as 12 ft in this area, due to the local winds and a component of longer period NW swell. NW swell in excess of 8 ft covers most of the area north of 06N and west of 115W. A second and stronger cold front will approach the northwest section of the area tonight, and move eastward across the waters north of 20N through early next week. The main impact will be a new round of NW swell, with combined seas in excess of of 12 ft to as high as 20 ft propagating across most of the region north of 12N and west of 120W Sun through late Mon. During the early to middle part of next week, the leading edge of this next round of northwest swell will mix with shorter period northeast and east swell emerging from the gap wind areas,
and possibly even southerly swell, to create an area of mixed seas south of 12N between 95W and 110W.