AXPZ20 KNHC 200325
Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0405 UTC Fri Jul 20 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
Based on 0000 UTC surface analysis and satellite imagery through
A tropical wave is analyzed N of 07N along 99W moving W at 10 to
15 kt. Scattered moderate isolated strong convection is noted
from 12N to 14N between 95W and 103W.
A tropical wave is analyzed from 06N to 15N along 107W moving W
at 15 kt. Scattered moderate isolated strong convection is noted
from 07N to 09N between 105W and 112W.
A tropical wave is analyzed from 06N to 15N along 129W moving W
at 15 kt. Scattered moderate convection from 08N to 12N between
127W and 130W.
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
The monsoon trough extends across the entire basin from 09N78W
to 10N112W to 12N128W to 11N140W. Scattered moderate isolated
strong convection is noted from 07N to 10N east of 112W.
Scattered moderate convection is noted from 08N to 14N between
117W and 134W.
OFFSHORE WATERS WITHIN 250 NM OF MEXICO...
A surface ridge will persist from 31N134W to the Revillagigedo
Islands for the next few days, maintaining gentle to moderate
breezes across the Mexican offshore waters into early next week.
Southerly cross-equatorial swell will propagate into the region
by late Fri, allowing seas to build to 5 to 7 ft in open waters
into early next week.
In the Gulf of Tehuantepec, strong N gap wind flow will return
late Sat, producing mixed seas south of the Gulf as wind waves
generated near Tehuantepec encounter the longer period southerly
swell. The gap winds will be due to lowering pressure south of
the region along with localized drainage flow.
OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND
WITHIN 750 NM OF ECUADOR...
Gulf of Papagayo: Fresh to strong nocturnal easterly winds,
accompanied by 6 to 8 ft seas, are expected into early next week.
Gentle to moderate easterly winds are forecast elsewhere N of
the monsoon trough which meanders between 07N and 10N. Moderate
southerly winds are expected S of the trough axis for the next
several days, accompanied by 4 to 6 ft seas.
Long period cross-equatorial southerly swell will continue to
propagate N, reaching the far offshore waters between 05N and
14N W of 86W Sun night, and the coast of Central America Mon.
Looking ahead, global models are showing increased southwesterly
flow into the monsoon trough starting by mid week. Along with
strong gap winds through the Gulf of Papagayo, this will help
develop multiple low pressure areas along the monsoon trough in
the offshore waters west of Costa Rica and Nicaragua. Expect
increased showers and thunderstorms in this area into mid week.
REMAINDER OF THE AREA...
A surface trough will move into the waters north of 27N between
125W and 135W Fri through Sun, weakening the subtropical ridge,
helping maintain moderate to fresh trade winds farther south.
Large long period southerly swell is moving across the equator
between 90W and 125W, and will continue to propagate northward,
affecting an area S of 17N between 80W and 133W by Sun night.
Long period northerly swell will propagate into forecast waters
N of 27N between 130W and 140W during the upcoming weekend, and
then subside on Mon.