| HOME | ARCHIVES | FORECASTS | IMAGERY | ABOUT NHC | RECONNAISSANCE |

Eastern North Pacific Tropical Weather Discussion (Text)



968 
AXPZ20 KNHC 201556
TWDEP 

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1605 UTC Mon Aug 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
meteorological analysis.

Based on 1200 UTC surface analysis and satellite imagery through 
1500 UTC. 

...TROPICAL WAVES...

A tropical wave along 90W-91W is moving W near 20 kt. Satellite 
imagery suggests two short amplitude waves are moving through 
this region between 86W and 96W and reorganizing. Scattered 
moderate to strong convection along the monsoon trough described 
below, and from 11N to the Mexican coast between 87.5W and 
96.5W. 

A tropical wave along 111W-112W is moving W around 15 kt. 
Significant convection currently with this wave is confined near 
the monsoon trough and described below. 

A tropical wave along 129W is moving W around 15 kt. Scattered 
moderate to strong convection is found from 13N to 17.5N between 
121W and 136W.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... 

The monsoon trough extends from low pres 1010 mb near 09N74W and 
meanders WNW to near 12N123W where it terminates. The ITCZ 
extends from 12N129W to beyond 11N140W. Widely scattered 
moderate to strong convection is seen within 180 nm N and 240 nm 
S of the monsoon trough between 84W and 122W. Scattered moderate 
to strong convection is within 45 nm N and 150 nm S of the ITCZ 
between 130W and 140W.

...DISCUSSION...

OFFSHORE WATERS WITHIN 250 NM OF MEXICO... 

A weak surface ridge across the NE Pacific is centered on a 1030 
nm high near 46N137W and extends S and SE, entering the forecast 
waters near 30N130W, then extends SE to just beyond the 
Revillagigedo Islands. This ridge will support gentle to 
moderate NW winds across the offshore waters of Baja California 
through Wed before the ridge strengthens modestly and the 
pressure gradient tightens across Baja California Norte Thu and 
Fri. Seas will generally remain in the 4-5 ft range through Wed. 

Surface troughing over the Baja Peninsula will maintain a light 
wind regime over the Gulf of California through Fri night, and 
allow for afternoon sea breezes and nocturnal land breezes to 
dominate.

Strong N to NE gap winds will affect the Gulf of Tehuantepec Tue 
night through Thu night, and forecast to peak near 30 kt late Wed 
night. Seas of 4 to 6 ft during the daytime could build to 8 
ft each of these nights and 8-10 ft late Wed night.

OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND 
WITHIN 750 NM OF ECUADOR...

The monsoon trough will linger near 09N during the next few 
days. Winds on both sides of the trough axis will generally be 
light to moderate. The main exception to this will be over the 
Gulf of Papagayo, where moderate to fresh offshore winds will 
pulse to locally strong each night. Seas are expected to remain 
below 8 ft downstream of Papagayo during this time.

REMAINDER OF THE AREA...   

Hurricane Lane continues moving farther away into the Central 
Pacific. The area of seas above 8 ft generated by mixed swell in 
the vicinity of Lane moved to the W of 140W earlier this 
morning.

Elsewhere, the pressure gradient between ridging across the 
northern waters and the ITCZ will support gentle to moderate 
trades and 4-7 ft seas in mixed swell N of the ITCZ and W of 120W
through the middle of this week.

Sea heights will be relatively low for most of the forecast area 
this week. Mixed SE and SW swell will caused seas S of 02S and W 
of 105W to briefly build to 8 ft this morning and will continue 
later through Tue morning before subsiding less than 8 ft. A 
much more robust round of long period swell could arrive from 
the Southern Hemisphere toward the end of this week and cause 
seas near the Equator to begin building on Sat.

$$
Stripling


Standard version of this page

Alternate Formats
About Alternates - E-Mail Advisories - RSS Feeds

Cyclone Forecasts
Latest Advisory - Past Advisories - About Advisories

Marine Forecasts
Latest Products - About Marine Products

Tools & Data
Satellite Imagery - US Weather Radar - Aircraft Recon - Local Data Archive - Forecast Verification - Deadliest/Costliest/Most Intense

Learn About Hurricanes
Storm Names Wind Scale - Prepare - Climatology - NHC Glossary - NHC Acronyms - Frequently Asked Questions - AOML Hurricane-Research Division

About Us
About NHC - Mission/Vision - Other NCEP Centers - NHC Staff - Visitor Information - NHC Library

Contact Us


NOAA/ National Weather Service
National Centers for Environmental Prediction
National Hurricane Center
11691 SW 17th Street
Miami, Florida, 33165-2149 USA
nhcwebmaster@noaa.gov
Disclaimer
Privacy Policy
Credits
About Us
Glossary
Career Opportunities
Page last modified: Monday, 20-Aug-2018 15:56:40 UTC