897 
AXPZ20 KNHC 070911
TWDEP 

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0911 UTC Fri Sep 7 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
0815 UTC. 

...SPECIAL FEATURES...

Hurricane Olivia centered near 19.6N 131.2W at 07/0900 UTC or
1350 nm E of Hilo Hawaii moving WNW at 13 kt. Estimated minimum
central pressure is 955 mb. Maximum sustained wind speed is 110
kt with gusts to 135 kt. Numerous moderate to strong convection 
is within 90 nm of the center of Olivia, except within 75 nm in 
the NE quadrant. Olivia is forecast to move W of 140W into the 
Central Pacific basin Sat night while maintaining hurricane 
strength. See latest NHC forecast/advisory under AWIPS/WMO 
headers MIATCPEP2/WTPZ32 KNHC for more details.

Low pressure of 1009 mb is near 15N111W moving westward around 10
kt. This low is along a tropical wave which has an axis from 
07N111W to the low to 20N111W. Scattered moderate and isolated 
strong convection is within 240 nm in the NW semicircle of the 
low with scattered moderate from 08N to 11N between 111W and 
117W. This low may bring increasing winds and seas over a portion
of the Pacific waters roughly from 08N to 20N between 108W and 
120W Fri through at least Mon. This low has a medium chance of 
tropical cyclone formation during the next 48 hours.

...TROPICAL WAVES...

A tropical wave has an axis extending N of 04N along 85W across 
western Costa Rica to the NW Caribbean Sea, moving westward at 
10 to 15 kt. Only isolated showers and thunderstorms are 
currently accompanying the tropical wave.

A tropical wave has an axis extending from 08N99W to Mexico near
16N98W, moving westward at around 15 kt. Only isolated showers 
and thunderstorms are near the tropical wave axis.

Please see the Special Features section for information on the 
area of low pressure along a tropical wave that has an axis from 
07N111W to the low near 15N111W to 20N111W.

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

The monsoon trough axis extends from low pressure over northern 
Colombia near 10N74W to 08N82W to 10N97W to low pressure near 
15N111W to 10N118W, then resumes from 15N130W to 13N140W. 
Scattered moderate and isolated strong convection is from 09N to 
11N between 93W and 97W.

Scattered moderate to strong convection that developed inland 
over western Mexico is propagating offshore from 18N to 24N
within 180 nm of shore, moving across the entrance to the Gulf of
California.

...DISCUSSION...

OFFSHORE WATERS WITHIN 250 NM OF MEXICO... 

A surface trough will meander between the the Gulf of California 
and the Baja California Peninsula the next few days. A ridge
building between Baja California and departing Hurricane Olivia 
will produce moderate to fresh NW winds W of the Baja peninsula 
through early Sat. SW swell from a developing tropical low SW of
the offshore waters of southern Mexico will build seas to 7 to 8
ft by Sat.

Northerly winds will pulse to fresh Offshore of the Gulf of 
Tehuantepec through early morning. Gentle to moderate winds are 
expected elsewhere over the Mexico offshore waters through the 
weekend, with seas of 5 to 7 ft over the Pacific waters, and 1 to
3 ft over the Gulf of California. 

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

The monsoon trough will meander between 08N and 10N during the 
next few days. Winds on both sides of the trough axis will be 
gentle to moderate.

Long period SW swell moving into the region will build seas to 8
ft, at first between Ecuador and the Galapagos Islands through 
this morning, then into the waters of Colombia by late tonight, 
persisting through much of the weekend. The swell will begin to 
subside by the end of the weekend into early next week, with 
another set arriving by late Mon through Tue night.

REMAINDER OF THE AREA...   

Please see the Special Features section for details on Hurricane
Olivia, and on developing low pressure near 15N111W.

Otherwise, a ridge dominates the forecast waters N of 20N W of 
120W, with gentle to moderate winds. Seas generated by Olivia 
will continue to spread across the waters north of 12N and west 
of 120W over the upcoming weekend.
  
$$
Lewitsky