000
AXPZ20 KNHC 170905
TWDEP 

TROPICAL WEATHER DISCUSSION                                  
NWS NATIONAL HURRICANE CENTER MIAMI FL                      
1005 UTC TUE MAY 17 2016

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
0700 UTC.     
  
.INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...                

The monsoon trough axis was analyzed from 10N86W to 06N93W to
09N104W to 08N109W. The ITCZ axis was analyzed from 08N109W to
07N113W to 10N123W to 11N130W, then continues from 09N135W to
05N140W. A trough was analyzed from 14N129W to 10N133W to
06N134W. Scattered moderate convection was between 90 nm and 300
nm south of the axis between 86W-90W. Scattered moderate
convection was within 150 nm southeast of the trough from 08N-
14N. 

.DISCUSSION...                                             

1031 mb subtropical high pressure was analyzed north of the area
near 36N138W, with a ridge axis extending southeastward through
30N135W to 17N109W. The pressure gradient between the ridge and
the ITCZ/monsoon trough to the southwest is supporting mainly
moderate to fresh trade winds. Winds are enhanced northeast of a
surface trough from 14N129W to 10N133W to 06N134W, with the
0554Z ASCAT-B pass showing fresh to strong northeast winds
within 150 nm west of the trough from 11N-14N. The subtropical
high will migrate northwestward and merge with new high pres
behind a cold front well north of the area. The ridge axis will
shift west and weaken, shrinking the area of fresh trade winds
westward. Fresh to strong northeast winds should remain just
west of the trough until Wednesday afternoon. Scattered moderate
convection was within 150 nm southeast of the trough from 08N-
14N. Convection near this trough has waned over the last day or
so. The available moisture is expected to diminish further over
the next few days, further limiting the chance of significant
deep convection. 

Northwesterly to northerly swell has built seas to 8 ft north of
29N between 118W-126W this morning. This swell is originating in
an area of 20-30 kt winds just north of the forecast area off
the California coast. As the subtropical ridge shifts westward,
the winds and swell will follow suit. Combined seas to 9 ft are
expected over forecast waters north of 28N west of 127W by the
end of the forecast period early Thursday morning.

Scattered moderate to strong convection was found from 06N-08N
east of 84W while scattered moderate with isolated strong
convection was noted from 03N-05N east of 81W and elsewhere
within 60 nm of the coast from 01N-06N. Strong upper level
divergence can be found in this area between southwesterly flow
aloft to the east and northerly flow aloft to the west.
Conditions should remain favorable for sustained convection in
this area south of the Gulf of Panama through tonight, with low-
level moisture diminishing and winds aloft becoming less
favorable for vertical lift thereafter.

$$ 
Schauer