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Eastern North Pacific Tropical Weather Discussion



000
AXPZ20 KNHC 222156
TWDEP 

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
2031 UTC Sat Jul 22 2017

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 1800 UTC surface analysis and satellite imagery through
2130 UTC.

...SPECIAL FEATURES... 

Tropical Storm Greg is centered near 15.1N 125.2W, moving W at 
11 kt. Estimated minimum central pressure is 1001 mb. Maximum 
sustained winds are 45 kt with gusts to 55 kt. Scattered strong 
convection is noted within 90 nm NW and 60 nm across the SE 
semicircles. Little change in intensity is forecast through the 
next 24 hours with slow weakening expected thereafter as Greg 
tracks over cooler waters and a more stable atmosphere. Greg may 
weaken to a tropical depression by Tue. See the latest NHC 
forecast/advisory under AWIPS/WMO headers MIATCMEP2 WTPZ22 for 
more details.

Tropical Depression Nine-E is centered near 10.5N 99.3W, or 
about 385 nm S of Acapulco Mexico, moving WNW at 11 kt. 
Estimated minimum central pressure remains 1006 mb. Maximum 
sustained winds are 30 kt with gusts to 40 kt. Scattered moderate
to strong convection is observed in bands within 300 nm across 
the N semicircle. Conditions are favorable for significant 
strengthening during the next 24 to 48 hours, and it is forecast 
to become a tropical storm on Sun, possibly intensifying to a 
hurricane by Mon as it continues on a WNW track. See the latest 
NHC forecast/advisory under AWIPS/WMO headers MIATCMEP4 WTPZ24 
for more details.

Tropical Depression Ten-E is centered near 14.4N 113.5W, moving 
W at 6 kt with minimum central pressure of 1006 mb. Maximum 
sustained winds are 30 kt with gusts to 40 kt. Scattered strong 
convection is within 240 nm across the SW semicircle of the low.
This system is forecast to move slowly westward to west- 
northwestward at 10 kt or less through early next week, and will 
gradually strengthen. See the latest NHC forecast/advisory under 
AWIPS/WMO headers MIATCMEP5 WTPZ25 for more details.

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

The monsoon trough is ill-defined in the Eastern Pacific due to 
the presence of several lows and tropical cyclones. A segment of
monsoon trough is analyzed from 09N84W to 11N97W, and then 
resumes from 11N126W to 09N135W. The ITCZ extends from 09N135W to
08N140W. Scattered strong convection is noted from 03N to 08N 
between 79W and 82W. Scattered moderate isolated strong 
convection was noted within 120-150 nm either side of the 
monsoon trough between 124W and 133W. 

...DISCUSSION...

OFFSHORE WATERS WITHIN 250 NM OF MEXICO...

Gentle to moderate NW winds off the Baja California peninsula 
are expected to continue through the weekend, as high pressure 
of 1028 mb remains centered NW of the area near 34N138W and will
shift NW. Seas will remain 4 to 7 ft in a mix of long period 
north and southwesterly swell. Gentle southerly flow will 
generally prevail in the Gulf of California, except for moderate 
southerly flow over the northern Gulf. 

Moderate E winds are expected across most of the area between 
Tehuantepec and Acapulco tonight becoming E to SE through early 
Mon. Seas of 5-8 ft in mixed N and SW swell this morning will 
become 5-7 ft in S to SE wind swell being generated by T.D. The 
forecast track and intensity of T.D. Nine-E is expected to impact
the offshore waters within 250 nm of the coast of the Mexican 
States of Oaxaca and Chiapas tonight through Sun night and the 
offshore waters of the States of Michoacan, Guerrero Sun through
Tue. 

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

Across the Gulf of Papagayo, moderate to fresh offshore winds 
will pulse to fresh each night with nocturnal drainage flow 
through the week, occasionally building max seas to 8 ft in a 
mix of east swell and longer period southwest swell.

Gentle to moderate southerly winds are expected south of the 
monsoon trough axis E of 95W. Long period cross-equatorial SW 
swell creating 5-7 ft seas will continue to propagate into the 
waters reaching the coast of Central America through the weekend.
Another pulse of large southerly swell will move into the region
Mon and Tue.

REMAINDER OF THE AREA... 

The remnant low of T.D. 8-E has been absorbed into the larger 
monsoonal flow to the S of T.S. Greg. The pressure gradient 
between high pressure north of the area and an active zone of 
tropical systems between 10N and 16N will maintain fresh trade 
winds and 6-7 ft seas north of 20N the next several days. 
Northerly swell in the form of 7-8 ft seas will propagate S of 
32N between 125W and 135W the next two days.

$$
COBB