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Eastern North Pacific Tropical Weather Discussion



000
AXPZ20 KNHC 190937
TWDEP 

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1005 UTC Mon Aug 19 2019

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. 

...SPECIAL FEATURES... 

A 1009 mb low pressure area is located near 13N92.5W, or about 
90 nm SW of the Guatemala/Mexico border. The low is moving WNW 
at around 5 kt which is expected to continue as it parallels the 
Mexican coast. The center has moved closer to the deep convection
on the NW side, with new convection also developing on the SE 
side in the past few hours. Numerous moderate and scattered 
strong convection is noted within 240 nm in the NW quadrant, 
with scattered moderate and isolated strong convection elsewhere 
within 600 nm in the NW quadrant, and within 90 nm in the SE 
quadrant. The threat for heavy rainfall and potential flash 
flooding will be over Guatemala, Chiapas, and Oaxaca over the 
next couple of days. Fresh to strong winds and seas of 5 to 8 ft 
will gradually increase and build through the week. This low has 
a medium chance of tropical formation through the next couple of 
days.

A 1009 mb low pressure area is located near 13N119W, or about 900
nm SW of the southern tip of Baja California. The low is moving 
W at 5 to 10 kt. Numerous moderate and scattered strong 
convection is noted within 150 nm in the SW quadrant, with
scattered moderate and isolated strong convection elsewhere
within 240 nm in the W quadrant. Fresh to occasionally strong
winds and seas of around 8 ft are forecast to accompany the low. 
This low has a medium chance of tropical formation through the 
next couple of days.

Refer to the latest NHC Tropical Weather Outlook under 
AWIPS/WMO headers MIATWOEP/ABPZ20 KNHC for more information on 
both of these lows.

...TROPICAL WAVES...

A tropical wave axis is along 110W, moving W at around 5 kt. 
Scattered moderate convection is noted from 07N to 10N between 
105W and 108W, and also from 10N to 11N between 110W and 113W.

A tropical wave axis is along 130W/131W, moving W at around 5 
kt. A weak area of low pressure, around 1009 mb, is located just
to the E of the wave near 14N128W. Scattered moderate and
isolated strong convection is noted within 180 nm in the NW 
quadrant of the low, and also from 08N to 12N between 122W and
130W.

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

The monsoon trough extends from 09N79W to low pressure near
13N92.5W to 11N110W to low pressure near 13N119W to low pressure
near 14N128W to low pressure near 12N136W to 11N140W. Scattered
moderate and isolated strong convection is noted within 150 nm SW
of the coast of Central America E of 90W, and also within 150 nm
S of the axis between 95W and 100W. Scattered moderate 
convection is noted from 08N to 10N between 130W and 140W, and 
also from 11N to 13N between 138W and 140W.

OFFSHORE WATERS WITHIN 250 NM OF MEXICO...

Please see the Special Features section for more details about 
the low pressure area S of the Guatemala/Mexico border which is
approaching the Gulf of Tehuantepec region.

A weak high pressure ridge extends SE across the waters N of 20N 
bringing gentle to moderate NW winds. This ridge will slowly 
shift SE into the middle of the week, causing the pressure 
gradient to increase later today through the middle part of the 
week. This will support moderate to fresh NW winds offshore of 
Baja California Norte, becoming fresh to strong Tue night. A low 
pressure trough will develop along the Baja California peninsula 
Wed night through the end of the week, supporting the 
development of fresh SE to S winds in the northern Gulf of
California.

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

Please see the Special Features section for more details about 
the low pressure area S of the Guatemala/Mexico border.

Offshore winds will pulse to fresh in the Gulf of Papagayo 
through this evening, then again Wed night and Thu night. Long
period SW swell will impact the offshore waters W of Ecuador by 
the middle of the week, building seas to 5 to 8 ft, then subsiding
by the end of the week. Otherwise, mainly moderate W to SW winds
will prevail S of 10N, along with seas of 4 to 6 feet.

REMAINDER OF THE AREA...

Please see the Special Features section for more details about 
the low pressure area near 13N119W.

Weak low pressure of 1011 mb is near 11.5N136W, with limited
convection in its vicinity. The low is forecast to move W of 
140W by Tue.

A weak ridge extends SE from 1021 mb high pressure near 39N137W.
Recent scatterometer data showed mainly gentle trades N of the
monsoon trough, while altimeter data sampled 4 to 7 ft seas. The
ridging will remain in place through the week, with the pressure
gradient tightening, which will support increasing trades. The 
pressure gradient will also increase offshore of central and 
southern California by the middle of the week, sending fresh 
northerly swell of 7 to 9 ft into the waters N of 25N and E of 
125W.

$$
Lewitsky