000
AXPZ20 KNHC 232138
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL 
2205 UTC MON MAY 23 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 1800 UTC surface analysis and satellite imagery through
2030 UTC.
  
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...         

The monsoon trough extends from low pres 1008 mb near 09N77W to
08N96W to 11.5N105W to 08.5N118W to low pres 1009 mb near
07N128W to low pres 1011 mb near 07N137.5W to 05.5N140W.
Scattered moderate to strong convection is from 04N-10N between
83w and 107w. Widely scattered moderate to strong convection is
within 150 nm north and 120 nm south of the trough west of 108W. 

...DISCUSSION...   

A surface trough extends from low pressure near Las Vegas, NV to
the northern Gulf of California, where afternoon scatterometer
data suggested a weak low pressure center near 31N114W. Gentle
to moderate W to SW winds are expected across the northern Gulf
through this evening while variable light to gentle winds are
expected across the southern Gulf. Global models continue to
forecast the low pressure to remain nearly stationary across the
northern Gulf through Tuesday morning before dissipating, then
redeveloping again Tuesday night. Southwest to south winds
across the southeastern half of the low are expected to increase
to 20 kt tonight and again tomorrow night, with seas building 4-
5 ft.  

Farther west, the persistent eastern Pacific ridge has weakened
during the past 24 hours as a new cold front is moving southward
to along 32N and approaching the northern boundary of the
discussion area. The ridge now extends from a 1029 mb high
center near 36N148W and southeastward over the remainder of the
area to near 16.5N108W.  The pressure gradient between the ridge
and lower pressure across Baja California is producing moderate
to fresh north-northwest winds across the near and offshore
waters of the Baja Peninsula. Late afternoon thermal contrast
across the region is producing a fresh seabreeze across segments
of the Pacific waters near the peninsula, where seas are running
6-7 ft, with small isolated areas to 8 ft. Winds and seas will
diminish slightly later tonight as the peninsula cools after
sunset. The cold front will sink south into north portions of
the waters during the next 24-26 hours and dissipate, with
moderate high pressure sinking southward along 140W. This will
maintain similar ridging across the area through Wednesday
before the ridge strengthens modestly Wednesday night and
Thursday. 

The pressure gradient between the ridge and the monsoon trough
to the south and southeast is promoting moderate to fresh trade
winds generally south of 22N and west of 120W. Several weak and
transient areas of low pressure are currently present along the
monsoon trough, and forecast to continue to form along the
monsoon trough through the week. Trade winds near these low
centers may occasionally increase to fresh to strong across the
northern portion, especially as convection flares up near the
lows. Seas across this trade wind zone will remain 5-7 ft
through Wednesday night before the ridge strengthens and winds
and seas increase slightly to near 20 kt and 6-8 ft through
Thursday.

S OF 15N E OF 110W...

Light to moderate winds are expected to continue across the
forecast area south of the monsoon trough through the week, with
light and variable winds north of the trough. Combined seas of 3
to 5 feet will prevail through Wednesday morning, and then will
build to 4 to 7 feet for the remainder of the week as new cross-
equatorial southwesterly swell arrives. Active convection is
expected to continue about the monsoon trough through mid week. 

$$
Stripling