AXPZ20 KNHC 151545
Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1458 UTC Mon Oct 15 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
Based on 1200 UTC surface analysis and satellite imagery through
The center of newly named Tropical Storm Tara is located near
17.6N 104.4W at 15/1500 UTC or 80 nm S of Manzanillo Mexico
drifting WNW or 295 degrees at 1 kt. Estimated minimum central
pressure is 1001 mb. Maximum sustained wind speed is 40 kt with
gusts to 50 kt. Numerous moderate to strong convection is noted
within 120 nm NW and 60 nm SE semicircles. On the forecast
track, the center of Tara is expected to remain near or just
offshore of the southwestern coast of Mexico during the next
couple of days. Slow strengthening is forecast during the next
few days. See latest NHC forecast/advisory under AWIPS/WMO
headers MIATCPEP2/WTPZ32 KNHC for more details.
Gulf of California: A Gale Warning is in effect for the northern
Gulf of California through this evening. Strong to near gale
force NW winds will rapidly develop N of 27N in response to
robust high pressure building over the Great Basin of the United
States. Frequent gusts to gale force are also expected N of 30N,
with seas building to 9 or 10 ft. These marine conditions will
persist through Tue, but mainly N of 29N.
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
The monsoon trough extends from a 1007 mb low pressure centered
over the SW Caribbean near 15N82W, then across Nicaragua to near
12N87W to 15N97W. Another segment of the monsoon trough stretches
from 14N106W to 10N120W to 11N133W to 09N140W. A cluster of
moderate to scattered strong convection is seen over the Gulf of
Tehuantepec. Scattered moderate isolated strong convection is N
of 10N between 85W-93W, from 11N-14N between 98W-111W, from 09N-
12N between 111W-117W, and within 120 nm N of trough between
OFFSHORE WATERS WITHIN 250 NM OF MEXICO...
A ridge will continue to dominate the offshore waters W of Baja
California Peninsula producing mainly gentle to moderate NW to N
winds, and seas generally in the 4 to 6 ft range. Seas are
forecast to increase a foot or so by the end of the forecast
period as mixed swell generated by Tropical Storm Tara arrives.
Gulf of Tehuantepec: Next gap wind event is forecast to start
early on Wed with seas rapidly building to 10 ft by Wed
afternoon. This event will be associated with a ridge building
behind a cold front across the eastern slopes of Sierra Madre
Mountains in Mexico and the western Gulf of Mexico.
OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND
WITHIN 750 NM OF ECUADOR...
Moderate to fresh SW monsoonal flow will continue across the
region through Tue, with showers and thunderstorms expected to
continue along the Pacific coast of Central America. Long period
cross-equatorial SW swell will maintain 5 to 8 ft seas across the
forecast area during this time frame. By Tue night and Wed,
marine guidance suggests an increase in winds and seas across the
offshore waters from Costa Rica to Guatemala. This appears to be
associated with a broad area of low pressure moving from the SW
Caribbean into Central America during this time frame.
REMAINDER OF THE AREA...
A 1022 mb high pressure located N of area near 35N127W extends a
ridge across the northern forecast waters producing light to
gentle winds N of 20N, and gentle to moderate winds S of 20N and
N of the monsoon trough. The next cold front will approach the
far NW corner of the discussion area by this evening. Fresh to
strong southerly winds and seas to 9 ft are forecasted ahead of
the front. The front will reach a position from 30N139W to
28N140W on Tue morning, and from 30N138W to 26N140W on Wed
morning while weakening. Long period NW swell will follow the
front building seas of 8-10 ft.
Satellite-derived wind and altimeter data confirmed the presence
of moderate to fresh monsoonal flow from 05N to 13N between 100W
and 110W, and 05N and 10N between 110W and 125W, with an
associated area of seas of 7 to 9 ft in long period SW swell.