AXPZ20 KNHC 111008 CCA
Tropical Weather Discussion
NWS National Hurricane Center Miami FL
939 UTC Tue Aug 11 2020
Corrected monsoon trough section
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 0600 UTC surface analysis and satellite imagery through
Hurricane Elida is centered near 20.7N 113.0W at 11/0900 UTC
moving WNW at 12 kt. Estimated minimum central pressure is 980
mb. Maximum sustained wind speed is 80 kt with gusts to 100
kt. Numerous moderate to strong convection is noted within 45 nm
in the northeast semicircle and 90 nm southwest semicircle. Elida
is expected to remain at hurricane strength into tonight as it
moves farther west, then gradually dissipate through late week. Please
read the latest NHC Public Advisory at
https://www.nhc.noaa.gov/text/MIATCPEP4.shtml and Forecast/
Advisory at https://www.nhc.noaa.gov/text/MIATCMEP4.shtml for
A tropical wave axis is near 93W, extending southward from the
southern Mexico to 05N. 1009 mb low pressure was well defined on
an earlier Scatsat scatterometer pass where the wave axis
intersects the monsoon trough. The wave is moving westward at 10
to 15 kt. Numerous moderate to isolated strong convection is
noted from 10N to 14N between 90W and 95W. While there is not a
significant chance of development through the next couple of
days, there is a medium probability for these features to
contribute to the development of at least broad low pressure
farther to the west- northwest by late week into early next week.
In the short term, associated winds will increase to fresh to
strong and seas to around 8 ft through midweek in the area from
10N to 14N between 90W and 95W.
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
The monsoon trough extends from 08N78W 07N81W to 1009 mb low
pressure near 09N93W to 09N102W. The monsoon trough resumes from
15N112W to 11N140W. Scattered moderate and isolated strong
convection is noted from 08N to 12N between 98W and 106W.
Scattered moderate convection is from 09N to 12N between 115W and
OFFSHORE WATERS WITHIN 250 NM OF MEXICO...
Please see the special features section above for more on
Hurricane Elida. The system will bring increasing winds and seas
over portions of the offshore waters between Cabo San Lucas and
the Revillagigedo Islands through tonight. Rough surf and
dangerous rip currents are possible over coastal areas as well of
Baja California Sur.
Aside from Hurricane Elida, moderate to locally fresh winds
prevail over much of the waters off Baja California north of
Punta Eugenia, supported by the pressure gradient between high
pressure west of the area and lower pressure over Mexico. Gentle
to moderate northerly flow continues from Punta Eugenia southward
to Cabo San Lazaro. Light to gentle winds are noted south of
Baja California Sur. Fresh to strong gap winds are noted in the
Gulf of Tehuantepec. Gentle to moderate SE winds continue across
the Gulf of California.
Farther south, fresh to strong northerly winds will pulse for
the next several nights across the Gulf of Tehuantepec.
OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, and
WITHIN 750 NM OF ECUADOR...
Moderate southerly winds prevail south of the monsoon trough.
Fresh to locally strong gap winds, enhanced by the tropical wave
in the western Caribbean now crossing Central America, will prevail
across the Gulf of Papagayo. Wave heights are in the 4-6 ft
The moderate southerly winds will persist south of the monsoon
trough for the next several days. Fresh to occasionally strong
winds will prevail across the Gulf of Papagayo region and over
the waters downstream of the Gulf of Papagayo through the end of
REMAINDER OF THE AREA...
Please see the special features section above for more
information about Hurricane Elida.
The subtropical ridge extends across the waters north of 20N.
Moderate to locally fresh trade winds are noted north of the
monsoon trough to near 20N and west of 120W, with gentle to
moderate breezes elsewhere north of the monsoon trough.
Recent altimeter data confirmed seas to 8 ft just northwest of
the discussion area. This is longer period NW swell and it is
starting to reach the waters north of 28N west of 138W, but
should subside within 36 to 48 hours.
Farther south, monsoon flow has freshened south of the monsoon
trough between 100W and 120W. The locally generated wind waves
has combined with a subsiding southerly swell, maintaining seas
in the 5 to 7 ft range roughly from 05N and 10N between 105W and
120W. Seas will build from roughly to 6 to 8 ft 05N to 10N
between 120W and 130W by mid week. Low pressure persists along
the monsoon trough near 12N126W. This low as a low probability of
development in the next couple of days, but a high probability
through the next five days as it moves farther west.
In general, the active phase of the Madden Julian Oscillation
will be propagating across the eastern North Pacific forecast
waters. This feature will produce a favorable large scale
environment for active convection which will elevate the
potential for tropical cyclone development in these waters over
the next couple of weeks. The National Hurricane Center will
closely monitor this situation.