000
AXPZ20 KNHC 171014
TWDEP 

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1005 UTC Mon Jul 17 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 0600 UTC surface analysis and satellite imagery through
0900 UTC.

...SPECIAL FEATURES...

Tropical Storm Calvin is centered near 16.7N 139.7W at 17/0900
UTC moving W at 16 kt. Estimated minimum central pressure is
1000 mb. Maximum sustained wind speed is 45 kt with gusts to 55
kt. Scattered moderate convection is noted within 60 nm in a 
northern semicircle from the center. Seas 12 ft or greater are 
estimated to be up to 210 nm in a northern semicircle from the 
center. Calvin is forecast to approach the Hawaiian Islands 
during the next couple of days or so, bringing the potential for 
heavy rainfall and dangerous 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 97W and N of 04N, moving W at 10 to 15 
kt. The wave extends northward across the Gulf of Tehuantepec. 
Scattered moderate to isolated strong convection is evident from
11N to 13N between 94W and 98W.

A second tropical wave is along 116W from 03N to 17N, moving W 
at 10 to 15 kt. Scattered moderate convection is observed from 
07N to 09N between 114W and 116W. 

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

A monsoon trough extends westward from northern Costa Rica 
through 09N105W to 05N124W. Scattered moderate convection is 
seen from 02N to 10N between the Colombia/Costa Rica coast and 
93W, and from 05N to 13N between 103W and 114W. An ITCZ continues
from 05N124W through 04N130W to beyond 04N140W. Scattered 
moderate convection is evident from 04N to 09N between 121W and 
128W.

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

An earlier scatterometer satellite pass confirmed fresh northerly
gap winds across the Gulf of Tehuantepec earlier today. This is
due to a tighter pressure gradient between higher pressure over
the Gulf of Mexico and relatively lower pressure farther south
assisted by the passage of a tropical wave through the region.
Seas are likely as high as 7 ft downstream in the Gulf of
Tehuantepec, mixing with longer period southerly swell moving
into the region. Farther north, weak ridging persists,
maintaining gentle to moderate winds and slight to moderate seas.
Ample moisture along with easterly flow across the higher terrain
of northwest Mexico and Baja California is supporting isolated
clusters of showers and thunderstorms along the mountains, 
although this activity is mostly dissipating before it reaches
the coast.

For the forecast, the fresh to strong northerly winds are 
forecast to persist in the Tehuantepec region through mid week 
with seas building to 8 ft. Farther north, a ridge will continue 
to dominate the offshore forecast waters of Baja California 
through at least mid-week supporting gentle to moderate NW winds 
with seas in the 4 to 6 ft range, and in the Gulf of California 
with seas of 3 ft or less. 

...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 90W. 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, the 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 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 T.S. Calvin that is moving westward toward the central Pacific
basin. 

Aside from Calvin, a ridge prevails across the north waters anchored
by a 1028 mb high pressure center located north of the area near
37N137W. 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 west of 140W through early
Mon. Seas generated by Calvin will subside to less than 8 ft east
of 140W by Mon afternoon. Farther east, expect fresh to strong winds
and moderate to rough seas from 10N to 15N between 105W and 120W
as a weak impulse moves along the monsoon trough through mid 
week.

$$

Forecaster Christensen/Chan