000
AXPZ20 KNHC 010742
TWDEP

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1005 UTC Fri Sep 1 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
0730 UTC.

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

The monsoon trough axis extends from Costa Rica near 09N84W to
11N97W to 06N128W. The ITCZ continues from 06N128W to 07N137W. 
Scattered moderate to isolated strong convection is noted from 
02N to 09N between 77W and 98W and from 05N to 12N between 106W 
and 118W. Scattered moderate convection is noted from 04N to 15N 
between 98W and 106W. 

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

A surface trough extends from 18N117W to 25N113W. A 1008 mb low
pressure center is located along the trough near 22N115W. Ahead
of this trough and in a zone of upper-level diffluence, scattered
moderate convection is noted from the southern Gulf of California
southeastward along the Mexican coast. Light to gentle winds 
dominate the waters, except in the Gulf of California where 
moderate S winds prevail. Seas are generally 5 to 7 ft, except 2
to 4 ft in the Gulf of California.

For the forecast, pulsing fresh to locally strong S winds will
continue in the northern Gulf of California through tonight. 
Fresh to strong northerly winds will pulse in the Gulf of 
Tehuantepec tonight through Sat night. Winds will be moderate or
weaker elsewhere through Sat night. Winds will increase to fresh
nearshore Baja California Sun night through Mon night as the 
pressure gradient tightens along the peninsula. 

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

Light to gentle winds prevail across the offshore waters N of 
04N, except for moderate NE to E winds in the Papagayo region. 
Seas north of 04N are 4 to 6 ft in long-period south to 
southwest swell. To the south of 04N, including the waters 
offshore Colombia and in between Ecuador and the Galapagos 
Islands, moderate S winds with seas of 5 to 7 ft are present due
to long-period S to SW swell. Scattered thunderstorms are noted 
off Colombia, Panama, and Costa Rica ahead of a tropical wave
that is crossing Central America early this morning. 

For the forecast, moderate to locally fresh south to southwest 
winds will continue between the coast of Ecuador and the 
Galapagos Islands through the weekend. Long period S to SW swell 
will move through these waters into Sat, increasing seas to 8-9 
ft through early Sun. Swell of 6-8 ft will reach the waters 
offshore Panama and Costa Rica late Sat through late Sun. 
Elsewhere, light to gentle variable winds will prevail, except 
locally moderate to fresh near the Gulfs of Papagayo and Fonseca.

...REMAINDER OF THE AREA...

The post-tropical remnant low of former Tropical Cyclone Irwin 
is centered near 19N139W with an estimated central pressure of 
1010 mb. It is moving westward at 5 to 10 kt. A tight pressure 
gradient between the low and strong high pressure to its north is
keeping strong to near gale force winds in the northwest 
semicircle from the low to 23N W of 137W. Seas are 10-13 ft in 
this area. Elsewhere north of 18N and west of 123W, fresh N to 
NE winds and 8 to 10 ft seas prevail. Winds are mainly moderate 
or weaker across the remainder of the open waters, with seas of 5
to 7 ft.

For the forecast, the post-tropical remnant low of Irwin will 
continue moving westward, with a slightly slower motion expected,
moving W of 140W by tonight. Fresh to strong winds and elevated 
seas will continue to accompany the low, mainly in the NW 
semicircle. Elsewhere, northerly swell will propagate through the
open waters well W of Baja California through today, keeping 
seas of 6-10 ft N of 20N and W of 123W. Long period S swell will
push northward across the Equator today with seas of 8-9 ft 
south of 06N and east of 120W into Sat before subsiding late in 
the weekend. The broad north-south oriented surface trough with 
accompanying low pressure is expected to move from along 115W to
120W by the weekend, resulting in shifting winds.

$$
KONARIK