AXPZ20 KNHC 301015
Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1005 UTC Fri Oct 30 2020
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
Based on 0600 UTC surface analysis and satellite imagery through
Gulf of Tehuantepec Gale Warning...High pressure and cooler,
denser air follow a cold front that has moved across the western
Gulf of Mexico and now extends along the far southwest Gulf of
Mexico. Recent scatterometer data and regional observations
suggest this cooler air has punched through the Tehuantepec
isthmus and gale are likely ongoing into the Gulf of Tehuantepec.
These winds are expected to reach 40 kt through late today then
temporarily diminish to just below gale into Sat. A reinforcing
front is expected to move into the southwest Gulf by late Sat,
allowing a new round of gale force winds by Sun which should
persist through early next week. Short period northerly swell
will mix with longer period southerly swell to support seas in
excess of 8 ft well downstream of the Gulf of Tehuantepec. Peak
seas during this gale wind event are expected to build to around
16 ft Fri afternoon and then to near 18 ft Mon evening.
A tropical wave axis is along 86W, along the east coast of
Nicaragua, extending southward across Costa Rica to 05N, moving
westward at 15-20 kt. Associated convection is described
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
The monsoon trough axis extends from 11N85W to 14N110W to beyond
10N140W. Scattered moderate to strong convection is noted from
06N to 10N between 87W and 92W, from 10N to 13N between 95W and
100W, and from 10N to 14N between 112W and 118W.
OFFSHORE WATERS WITHIN 250 NM OF MEXICO...
High pressure west of Baja California is supporting gentle to
moderate northerly breezes across the Mexican offshore waters
off Baja California and the Gulf of California. Seas are mostly
2 to 4 ft in both the open waters and in the Gulf of California.
Divergence aloft on the southeast side of an upper trough west
of the area is supporting a few showers near the Revillagigedo
Islands. Seas will build to 4 to 6 ft in the waters of Baja
California by early next week. Elsewhere, little change is
expected through the next several days.
Farther south, moderate northerly winds are funneling off Cabo
Corrientes, and seas are likely 4 to 6 ft off the Jalisco and
Colima coasts in mostly southerly swell. Gentle winds and 3 to 5
ft elsewhere off southern Mexico outside of the Gulf of
Tehuantepec. Seas will start building tonight as increased
southerly swell moves into the area, reaching up to 9 ft off
Michoacan and Guerrero by late Sat, then subsiding into early
OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, and
WITHIN 750 NM OF ECUADOR...
Moderate south to southwest winds will prevail south of the
monsoon trough through Sun, with isolated areas of fresh winds
this afternoon overnight ahead of an approaching tropical wave.
Seas are expected to increase offshore of Guatemala and El
Salvador through Sat night due to gale force winds in the Gulf
of Tehuantepec pushing northerly waves into the area. Moderate
offshore gap winds are expected across the Papagayo region through
Sun before turning onshore Mon.
Active weather is expected across the waters north of 05N, from
the Papagayo region southeast into Central America and the Gulf
of Panama this afternoon and tonight.
REMAINDER OF THE AREA...
A broad ridge persists across the northern forecast waters west
of 120W. The gradient between the ridge and lower pressures
associated with the monsoon trough will support moderate to fresh
NE trade winds over an area roughly from 10N to 22N, west of
115W, for the next several days. Seas are 6 to 8 ft across this
region, in a mix of swell and easterly wind waves. Little change
is expected through today.
South of the monsoon trough, moderate to fresh S to SW winds
prevail between 100W and 130W, where seas are 7-9 ft. Minor
fluctuations in winds and seas are expected across this area
through the weekend.
Looking ahead, computer models suggest that a tropical wave
moving offshore of SW Mexico Sun and Mon could spawn a low
pressure center forming west of the offshore waters in the
vicinity of 10N110W by Mon morning, and move WNW through mid