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Eastern North Pacific Tropical Weather Discussion

AXPZ20 KNHC 270215

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
032 UTC Mon May 27 2019

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
0300 UTC.


...Heavy Rainfall Potential Over Central America...

A large low level cyclonic circulation that is typical for this 
time of the year, called a Central American Gyre, is forecast to 
persist across the far eastern tropical Pacific and Central 
America for the next several days. This will continue bringing 
abundant moisture and areas of heavy rainfall across portions of 
Central America. Computer model forecasts have begun to indicate 
the chance for increasing moisture and instability associated 
with this feature Tue through Wed and could lead to a very 
significant rainfall event. Life-threatening flash flooding and 
mudslides will be possible in areas of mountainous terrain. The
chance of tropical cyclone formation in this area remains low due
to its proximity to land and unfavorable upper-level winds. 
Please refer to your local meteorological service for more 


The monsoon trough extends across northern Costa Rica to a low 
pressure located near 10N88W 1008 mb to 07N100W to 06N120W TO 
06.5N130W. The ITCZ extends from 06.5N130W to beyond 07N140W. 
A cluster of moderate to strong convection is noted from 06N TO 
09N between 92W and 95W. Scattered moderate convection is seen
elsewhere from 04N to 09N between 89W and 97W. Similar convection
can be found from 07N to 12N between 100W and 107W, and from 07N
to 10N between 107W and 112W.



Gulf of California: A cold front is moving across northern Baja 
California into the Gulf of California. As a result, winds will 
begin to shift more NW tonight through Mon across the northern
Gulf. Expect SW to W winds in the 20 to 25 kt range, shifting to
the NW and N, with seas briefly building to 6 or 7 ft. Winds 
across central and southern portions will increase to 10-15 kt 
tonight through Tue with seas building 2-3 ft.

A weak ridge dominates the offshore forecast waters W of Baja 
California producing mainly gentle to moderate NW winds off the 
coast of the Baja California peninsula, and light to gentle NW 
to W winds over the remainder of the open waters off the coast of
Mexico. Seas are generally in the 5-7 ft range across the entire
area in a mix of SE and cross equatorial SW swell. High pressure
well NW of the region will build over the next few days. This 
will tighten the pressure gradient across the offshore waters to 
support fresh to locally strong NW to N winds across the waters 
off Baja California tonight through Tue night, with seas building
into the 6 to 8 ft range. 

Gulf of Tehuantepec: Fresh to strong northerly winds will pulse 
across the Tehuantepec region late tonight into early Monday 
morning, with seas of 7 to 8 ft. 


Please see the Special Features section for more information 
about the Central American Gyre, which will continue to bring 
locally heavy rains to parts of Central America and the adjacent
offshore waters through at least mid week.

Gentle to moderate SW to W winds prevail S of the monsoon 
trough, with seas in the 4-7 ft range. Moderate to locally fresh 
winds, and seas in the 5-6 ft range prevail N of the monsoon 
trough. Low pressure of 1008 mb embedded within the broad gyre 
will meander offshore the coast of Nicaragua the next couple of 
days. The monsoon trough will lift northward through the early 
part of the week, with southerly monsoon flow strengthening, 
potentially to 20-25 kt by Tue. Seas will build to 8-12 ft by mid
week in this enhanced monsoon flow.


High pressure of 1027 mb centered NW of the area near 34N139W 
extends a ridge SE to near the Revillagigedo Islands. The 
pressure gradient between the ridge and lower pressure in the 
vicinity of the ITCZ is supporting moderate to fresh NE winds 
across much of the area N of the ITCZ and W of 120W. Moderate to 
fresh winds will continue to prevail over this area the next 
several days.

SW cross equatorial swell will dominate the forecast waters S of 
10N and W of 95W for the next few days, with new swell arriving 
late Tue. Seas 8 ft or greater will cover much of the forecast 
waters S of 12N between 85W and 112W by late Tue.