319
AXPZ20 KNHC 200901
TWDEP
Tropical Weather Discussion
NWS National Hurricane Center Miami FL
616 UTC Mon Aug 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
meteorological analysis.
Based on 0600 UTC surface analysis and satellite imagery through
0900 UTC.
...TROPICAL WAVES...
A tropical wave has an axis from 06N92W to 20N90W, moving W
between 20 and 25 kt. Scattered moderate and isolated strong
convection is noted from 05N to 08N between 88W and 92W.
A tropical wave has an axis from 04N113W to 17N112W, moving W
around 15 kt. Scattered moderate convection is seen from 06N to
08N between 108W and 116W.
A tropical wave has an axis from 04N131W to 16N129W, moving W
around 15 kt. Scattered moderate and isolated strong convection
is found within 90 nm either side of a line from 17N122W to
13N130W.
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
The monsoon trough extends from low pres 1010 mb near 09N74W to
08N78W to 09N92W to 11N120W. The ITCZ extends from 09N133W to
09N136W to beyond 10N140W. Scattered moderate and isolated strong
convection is present from 07N to 09N between 95W and 100W.
Scattered moderate convection is observed from 09N to 12N between
118W and 121W and from 07N to 11N W of 137W.
...DISCUSSION...
OFFSHORE WATERS WITHIN 250 NM OF MEXICO...
Surface ridging enters the forecast waters near 32N132W, then
extends SE to near the Revillagigedo Islands. This feature will
support gentle to moderate NW winds through Tue. The ridge will
weaken slightly during the middle of the week as passing low pres
weakens the N side of the ridge. This will allow winds to
slacken a bit to between light and gentle late Tue and Wed. The
ridge will then rebuild Thu, bringing a slight increase to the
winds once again Thu and Fri.
Surface troughing over the Baja Peninsula will maintain a light
wind regime over the Gulf of California through Fri night.
Strong N to NE gap winds will affect the Gulf of Tehuantepec Tue
through Thu night. This event is forecasted to peak Wed night,
when winds could reach 30 kt and seas could build to 10 ft.
OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND
WITHIN 750 NM OF ECUADOR...
The monsoon trough will linger near 09N during the next few
days. Winds on both sides of the trough axis will generally be
light to moderate. The main exception to this will be over the
Gulf of Papagayo, where winds will pulse to fresh and become
locally strong each night. Winds will peak tonight, when strong
winds are expected to affect the area from 10.5N to 11.5N E of
88W. Seas are expected to remain below 8 ft.
REMAINDER OF THE AREA...
Hurricane Lane continues moving farther away into the Central
Pacific. The area of seas above 8 ft generated by mixed swell in
the vicinity of Lane moved to the W of 140W earlier this
morning.
Elsewhere, the pressure gradient between ridging across the
northern waters and the ITCZ will support gentle to moderate
trades and 4-7 ft seas in mixed swell N of the ITCZ and W of 120W
through the middle of this week.
Sea heights will be relatively low for most of the forecast area
this week. Mixed SE and SW swell will cause seas S of 02S and W
of 112W to briefly build to 8 ft later this morning through Tue
morning. A much more robust round of long period swell could
arrive from the Southern Hemisphere toward the end of this week
and cause seas near the Equator to begin building on Sat.
$$
CAM
