687 
AXPZ20 KNHC 152128
TWDEP 

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
2205 UTC Thu May 15 2025

Tropical Weather Discussion for the eastern Pacific Ocean from
03.4S to 30N, east of 120W including the Gulf of California, and
from the Equator to 30N, between 120W and 140W. The following
information is based on satellite imagery, weather observations,
radar, and meteorological analysis.

Based on 1800 UTC surface analysis and satellite imagery through
2100 UTC.

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

The monsoon trough extends from a 1009 mb low pressure located
over northern Colombia near 10N75W to another 1010 mb low 
pressure situated near 09N99W to 08N120W. The ITCZ continues 
from 08N120W to beyond 07N140W. Scattered moderate to isolated 
strong convection can be found from 03N to 06N between 80W and  
90W, from 08N to 11N between 88W and 90W, and from 06N to 10N 
between 90W and 112W.

...OFFSHORE WATERS WITHIN 250 NM OF MEXICO...

A ridge dominates the offshore forecast waters of Baja California
extending SE to near the Revillagigedo Islands. This system
supports moderate to fresh NW winds off the Baja California 
peninsula, with seas in the 5 to 7 ft range. Similar wind speeds
from the NW are also noted between Cabo Corriente and the 
Revillagigedo Islands where seas are 5 to 6 ft. Gentle to 
moderate winds are blowing across the central and south parts of 
the Gulf of California. Elsewhere across the Mexican offshore 
waters, including the northern Gulf of California, light winds
prevail. Seas of 3 to 5 ft are noted elsewhere except 1 to 3 ft 
in the Gulf of California. 

For the forecast, a ridge will continue to dominate the weather 
pattern across the offshore waters of Baja California through 
the upcoming weekend, supporting moderate to fresh NW winds and 
moderate to rough seas. Moderate or weaker winds and moderate 
seas, primarily in SW swell, will prevail elsewhere. A low is 
forecast to develop over the northern Gulf of California by Fri 
night producing fresh to strong S to SW winds through Sat night. 
Looking ahead, seas generated offshore California by fresh to 
strong northerly winds will reach the waters N of Punta Eugenia 
Sun night into Mon. This swell event will continue to propagate 
southward, mainly across the waters between 118W and 130W on Tue.

Of note: Today marks the first day of the eastern North Pacific 
hurricane season, which will run until November 30. Long-term 
averages for the number of named storms, hurricanes, and major 
hurricanes are 15, 8, and 4, respectively. The first tropical
storm will be named Alvin. As it is normal for this time of the
year, weak lows can be noted along the monsoon trough.

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

Recent scatterometer data indicate moderate NE winds downwind of
the Gulf of Papagayo and the coast of Nicaragua to near 100W. 
Light to gentle winds are elsewhere north of the monsoon trough. 
Gentle to moderate winds are south of the monsoon trough. Winds 
and seas are higher near thunderstorms along the monsoon trough.
Seas are in the 5 to 7 ft range between Ecuador and the Galapagos
Islands, reaching 8 ft south and SW of the Galapagos Islands. 
Elsewhere, seas are in the 4 to 6 ft range in SW swell.

For the forecast, abundant moisture drawn in by a very moist and
unstable southerly wind flow is expected to persist across the 
offshore waters of Costa Rica, Panama and Colombia through the
upcoming weekend supporting the development of showers and 
thunderstorms over those waters. Gentle to moderate winds will 
prevail across the region through Sun, then diminish through 
Mon. Expect moderate to rough seas in long period SW swell 
between Ecuador and the Galapagos Islands through tonight.  
Slight to moderate seas, primarily in SW swell, will prevail 
elsewhere.

...REMAINDER OF THE AREA....

A ridge prevails over the waters north of the ITCZ and west of 
110W. The pressure gradient between the ridge and lower pressure 
in the vicinity of the ITCZ is supporting moderate to fresh 
trade winds north of the ITCZ and west of 120W. Based on latest 
altimeter data, an area of 8 to 10 ft seas is noted from 18N to
26N W of 130W primarily in N swell. Gentle to locally moderate 
winds and moderate seas are noted elsewhere in a mix of swell.

For the forecast, the pressure gradient between high pressure 
over the north waters and low pressure in the vicinity of the 
ITCZ will support moderate to fresh NE winds north of the ITCZ 
and west of 120W through early next week. The NW swell will 
combine with seas from trade winds from 10N to 20N west of 130W 
through at least Sat. Looking ahead, a new swell event will reach
the N waters Sun night into Mon, building seas to 10 or 11 ft N
of 25N between 118W and 130W late on Mon. 

$$
GR