AXPZ20 KNHC 200921
Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1005 UTC Sat Oct 20 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 0600 UTC surface analysis and satellite imagery through
Tropical Storm Vicente is centered near 14.0N 93.1W or about 80
miles SW of Tapachula Mexico at 20/0900 UTC moving W-NW at 6 kt.
Estimated minimum central pressure is 1005 mb. Maximum sustained
wind speed is 35 kt with gusts to 45 kt. Scattered moderate
isolated strong convection is observed within 90 nm of the
center. An increase in forward speed and a turn toward the west
is expected today followed by a turn toward the southwest later
tonight. On the forecast track, the center of Vicente will
gradually move farther away from the coasts of Guatemala and
southeastern Mexico today. Vicente will contribute to abundant
and persistent tropical moisture along the coasts of Guatemala
and El Salvador, with precipitation guidance suggesting 3 to 6
inches of rain, with local amounts to 10 inches, possible across
portions of the Pacific coast of southeastern and southern
Mexico through the middle of next week. This rainfall could
produce life-threatening flash flooding and landslides within
mountainous terrain. Refer to the latest NHC forecast/advisory
under AWIPS/WMO headers MIATCMEP3/WTPZ23 KNHC for additional
Tropical depression 24E is centered near 15.1N104.9W, or about
270 miles S of manzanillo Mexico at 20/0900 UTC moving W at 8
kt. Estimated minimum central pressure is 1007 mb. Maximum
sustained wind speed is 30 kt with gusts to 40 kt. Currently
numerous strong convection is observed within 150 nm SW of the
center with scattered moderate to strong convection noted
elsewhere in bands within 180 nm NE and 240 nm SW semicircles of
center. A motion toward the northwest is forecast on Sun and
Mon with the tropical cyclone transversing the Mexican offshore
waters. Refer to the latest NHC forecast/advisory under
AWIPS/WMO headers MIATCMEP4/WTPZ24 KNHC for additional details.
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
The monsoon trough extends W off the Caribbean coast of Colombia
at 10N76W to the Pacific coast of Costa Rica at 10N86W, then
turns NW to 12N91W where it loses identity in the cyclonic
circulation associated with tropical cyclone Vicente. The
monsoon trough resumes along 14N between Vicente and TD 24E,
then resumes at 15N107W and continues SW through the surface low
at 12N118W to 09N122W where scatterometer winds indicate a
transition to an ITCZ, which then continues W-NW to beyond
Scattered moderate isolated strong convection is observed within
30 nm either side of a line from 06N81W to 12.5N88W, within
90 nm either side of a line from 12N92W to 19N107W and within 30
nm either side of lines from 10N131W to 12N140W and from 07N134W
OFFSHORE WATERS WITHIN 250 NM OF MEXICO...
See the Special Features paragraph for details on Tropical
Cyclone Vicente and newly formed Tropical Depression 24E.
A surface ridge will meander across the offshore waters from
23N117W to 21N106W through Mon. Gentle NW to N flow is expected
N of 20N W of 110W through early Tue. The pressure gradient is
then forecast to tighten, supporting moderate northerly flow W
of the Baja California Peninsula during the middle of next week
as large southerly swell propagates N through the waters W of
Gulf of California: Light, mostly northerly flow is expected
through the middle of next week when large southerly swell will
reach the southern approach to the gulf waters.
OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND
WITHIN 750 NM OF ECUADOR...
Gentle to moderate southwesterly to westerly monsoonal flow will
dominate the offshore waters through Sat night. Fresh SW winds
are expected to develop S of 05N E of 90W on Sat night through
Sun night with seas to 9 ft.
REMAINDER OF THE AREA...
Refer to the Special Features paragraph above for details on
Tropical Depression 24E.
Elsewhere, a surface ridge will meander from near 30N135W to
23N117W through the upcoming weekend. Fresh winds, and 7 to 9 ft
seas, are observed across the tropical waters from 13N to 19N W
of 133W. These conditions will shift W of the area on Sun night.