AXPZ20 KNHC 242205
Tropical Weather Discussion
NWS National Hurricane Center Miami FL
2205 UTC Mon Sep 24 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 1800 UTC surface analysis and satellite imagery through
A broad area of low pressure is analyzed as 1008 mb surface low
near 14N105W. Numerous moderate isolated strong convection is
observed within 120 nm NW semicircle of the low. Scattered
moderate convection in bands are elsewhere from 09N to 18N
between 99W and 110W. Fresh southwesterly monsoonal flow is well
south of the low, across the tropical waters from 06N to 10N
between 101W and 117W. Environmental conditions are expected to
be conducive for development, and a tropical depression is
likely to form within the next day or so while the system moves
west-northwestward well off the coast of Mexico. There is still
much uncertainty at this time, however for now expect fresh to
strong winds, and building seas, to spread north across the
offshore waters from 15N to 23N on Wed through Sat, with mixed
swell, in the form of 8 to 16 ft seas. Higher winds are highly
possible across the waters west of the Baja Peninsula over the
remainder weekend. Refer to the East pacific tropical Weather
Outlook under WMO/AWIPS headers ABPZ20 KMIA/MIATWOEP for
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
The monsoon trough extends from 10N85W to 10N100W to a low
pressure...possible tropical cyclone...near 14N105W to 11N110W
to 11N125W to 10N136W. Numerous moderate isolated strong
convection is in the Gulf of Panama and from 06N to 09N between
85W and 91W. Scattered moderate convection is elsewhere from 07N
to 14N between 113W and 130W, and from 07N to 18N W of 130W.
OFFSHORE WATERS WITHIN 250 NM OF MEXICO...
See the Special Features paragraph above. Surface ridging to the
west will continue to retract away of the region during the next
few days as a surface low, with a high chance of becoming a
tropical cyclone, tracks west-northwest. Gentle to moderate
northwest flow is forecast west of the Baja California through
Thu morning, then light to gentle winds are expected through
Gulf of California: Gentle to locally moderate variable winds
forecast across the gulf waters north of 30N through much of the
period. Otherwise, light to gentle variable winds expected
across the remainder gulf waters through the weekend.
Gulf of Tehuantepec: Fresh to locally strong nocturnal drainage
is forecast tonight with a strong event expected Sat morning. A
low pressure is forecast to develop over Guatemala offshore
waters on Thu along with fresh to strong winds. The low will
move west to south of Tehuantepec on Friday where it is expected
to slightly intensify. Seas are forecast to build to 14 ft over
OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND
WITHIN 750 NM OF ECUADOR...
Gulf of Papagayo: Moderate to locally fresh east nocturnal
drainage flow expected through Thu night with seas building to
Light and variable winds are forecast elsewhere north of the
monsoon trough which is meandering between 09N and 12N. Moderate
southwest flow is forecast south of the monsoon trough.
REMAINDER OF THE AREA...
See the Special Features paragraph above. A broad ridge
continues across the subtropics accompanied by moderate to
locally fresh anticyclonic flow south of 23N west of 120W.