000
AXPZ20 KNHC 161548
TWDEP

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1605 UTC Sun Jul 16 2023

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 1200 UTC surface analysis and satellite imagery through
1500 UTC.

...SPECIAL FEATURES...

Calvin was downgraded to a tropical storm at 16/1500 UTC. At this
time Calvin is centered near 16.0N 134.8W at 16/1500 UTC moving 
WNW at 14 kt. Estimated minimum central pressure is 993 mb. 
Maximum sustained wind speed is 60 kt with gusts to 75 kt. 
Numerous moderate to isolated strong convection is noted within 
60 nm NE semicircle of center. Seas in excess of 12 ft seas 
extend within 180 nm N semicircle and 90 nm S semicircle with 
maximum seas estimated to reach 28 ft. On the forecast track, the 
center of Calvin will move into the central Pacific basin late 
tonight or early Monday morning and approach the Hawaiian Islands
on Tuesday. Weakening is forecast to continue during the next 
few days. Swells generated by Calvin are expected to begin reaching the
Hawaiian Islands during the next couple of days. These swells are
likely to cause life-threatening surf and rip current conditions.

Please read the latest HIGH SEAS FORECAST issued by National 
Hurricane Center at web-site 
https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml and the latest 
T.S. Calvin Forecast/Advisory and Public Advisory at 
www.hurricanes.gov for more details. 

...TROPICAL WAVE...

A tropical wave is along 92W and N of 04N, moving W at 10 to 15 
kt. The wave extends northward over SE Mexico. Convection is
limited near the wave axis. 

A second tropical wave is along 112W from 04N to 18N, moving W 
at 10 to 15 kt. Scattered moderate convection is observed from
08N to 11N between 109W and 115W. 

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

The monsoon trough extends from 10N84W to 08N100W to 08N126W. 
The ITCZ stretches from 07N135W to beyond 07N140W. Scattered 
moderate to isolated strong convection is noted from 05N to 08N 
between 78W and 85W, from 02N to 08N between 94W and 102W, from 
12N to 16N between 94W and 102W, and from 02N to 11N between 109W
and 125W.

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

A surface ridge dominates the offshore forecast waters of Baja 
California. Gentle to moderate NW winds prevail with seas of 4 
to 6 ft. Light to gentle southerly winds are over the Gulf of 
California where seas are in the 1 to 3 ft range. Fresh to 
strong northerly winds prevail in the Tehuantepec region with 
seas of 4 to 6 ft. Elsewhere across the remainder of the Mexican 
offshore waters, light to gentle winds and seas of 4 to 5 ft in 
SW swell are noted. An area of showers and thunderstorms is seen
over the N and central parts of the Gulf of California moving
westward. Winds and seas could be higher near thunderstorms.

For the forecast, the ridge will continue to dominate the offshore
forecast waters of Baja California through Tue supporting gentle
to moderate NW winds with seas in the 4 to 5 ft range. Similar 
wind speeds are expected in the Gulf of California with seas of 3
ft or less. Fresh to strong northerly winds are forecast to pulse
in the Tehuantepec region through mid-week with seas building to
8 ft on Tue. 

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

Fresh to strong NE to E winds prevail across the Papagayo region
and downwind to about 89W. Seas are 5 to 7 ft within these 
winds. Light to gentle winds and seas of 4 to 5 ft are noted over
the remainder of the offshore waters north of 03N. Gentle to 
moderate southerly winds are observed south of 03N where seas are
4 to 6 ft.

For the forecast, fresh to strong NE to E winds are forecast to
pulse in the Papagayo region through the middle of the week with
seas building to 8 or 9 ft. Light to gentle winds will dominate 
the remainder of the offshore forecast waters, with the exception
of gentle to moderate southerly winds between Ecuador and the 
Galapagos Islands, and moderate to locally fresh NE to E winds 
across the offshore waters of Guatemala and El Salvador. Outside 
of the Papagayo region, seas of 4 to 5 ft in SW swell are 
expected. However, seas generating in the Papagayo area will 
spread across the offshore waters of Guatemala and El Salvador 
building seas to 5 to 7 ft.

...REMAINDER OF THE AREA...

Please see the SPECIAL FEATURES section above for more information
on Calvin that is now a tropical storm. 

Aside from Calvin, a ridge prevails across the north waters anchored
by a 1024 mb high pressure center located N of the area near 
37N136W. Gentle to moderate winds are noted under the influence 
of the ridge. Wind and seas could be higher near the convective 
activity along the ITCZ/Monsoon Trough.

For the forecast, Calvin will move to 16.4N 137.3W this evening, 
and will be just W of the forecast region near 17.0N 140.6W Mon 
morning. Seas in excess of 8 ft generating by Calvin, will continue
to propagate across the open waters, covering the area from 12N 
to 23N W of 135W by Mon morning. An area of fresh to strong E 
winds, with seas to 8 ft is forecast to develop to the S and SW 
of the Tehuantepec region by Mon and could be associated with a 
developing low pressure along the monsoon trough.

Looking ahead, an area of low pressure could form well south of 
the coast of southwestern Mexico during the next several days. 
Some gradual development of this system is possible thereafter as
it moves generally west-northwestward over the central portion 
of the eastern Pacific basin. Refer to the latest NHC Tropical 
Weather Outlook at www.hurricanes.gov for more details.

$$
GR