Tropical Weather Discussion

axpz20 knhc 230356

Tropical weather discussion
NWS National Hurricane Center Miami FL
0405 UTC Sat Jun 23 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 0000 UTC surface analysis and satellite imagery through 
0300 UTC. 

...Intertropical convergence zone/monsoon trough...

The monsoon trough extends from 10n85w to a 1010 mb low pressure 
near 12n104w to a 1010 mb low pressure near 12n116w to 09n121w. 
The ITCZ continues from 09n121w to 08n130w to 09n139w. Scattered 
moderate convection is noted from 10n to 15n between 100w and 
120w, and from 05n to 13n to the west of 130w.


Offshore waters within 250 nm of Mexico...

Moderate NW winds are forecast to continue across the waters 
west of Baja California through Sat morning before beginning to 
gradually diminish through the weekend, as a broad surface 
trough shifts westward to the NE Pacific waters. Winds west of 
the peninsula will become variable less than 15 kt through the 
weekend. However, southerly winds will increase inside the Gulf 
of California this weekend, becoming fresh to strong 
southeasterly N of 28n Sat morning, continuing into Sun morning. 
Seas in the northern Gulf of California will build to 6-9 ft by 
Sat afternoon, then subside sun along with a decrease in surface 

Further south, long period cross-equatorial SW swell reaches the 
waters off southern Mexico with seas to 6 ft, forecast to 
increase to 7 ft by Sat afternoon. Seas are expected to subside 

Offshore waters within 250 nm of Central America, Colombia, and 
within 750 nm of Ecuador... 

The monsoon trough will meander between 09n and 13n the next 
several days. Light to gentle winds will prevail north of the 
monsoon trough, with gentle to moderate S to SW winds expected 
south of the trough axis. Long period cross-equatorial SW swell 
is across southern forecast waters with seas to 8 ft. The swell 
will propagate further north to the offshore waters of Costa 
Rica and Colombia today, Sat and then will gradually subside 
through sun.

Remainder of the area... 

High pressure north of the area centered near 36n138w extends a 
ridge se to near the revillagigedo islands. Moderate to fresh 
tradewinds prevail from 11n to 22n west of 135w with seas 
generally ranging between 6 to 7 ft. Light to gentle winds 
dominate the remainder of the basin. 

Fresh to strong tradewinds from 07n to 09.5n between 138 and 
140w will gradually diminish through early Sat as a trough west 
of the area continue to move west. Seas are currently 8 ft in 
mixed swell and will gradually subside to 6-7 ft through Sat. 
Northerly swell will propagate into the northern waters with 
seas building to 8 ft north of 29n between 123w and 127w early 
sun. Cross-equatorial southerly swell with seas to 9 ft are 
south of 10n and west of 90w and will continue through Sunday 

Low pressure centered near 12n116w and embedded along the 
monsoon trough has an estimated pressure of 1010 mb. Model 
guidance shows this low emerging from the trough and drifting 
northward with a gradual increase in intensity through the 
weekend. Active thunderstorms will continue in the vicinity of 
this low through the weekend and early next week.

A 1010 mb low pressure is near 12n104w generating scattered 
moderate convection from 10n to 15n between 100w and 115w. 
Global models guidance indicate there is a high chance for this 
low to develop into a tropical cyclone SW of Mexico early next 



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