AXPZ20 KNHC 291605
Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1605 UTC Wed Jun 29 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
Based on 1200 UTC surface analysis and satellite imagery through
A tropical wave extends from low pressure of 1008 mb along the
Monsoon Trough near 09N97W north to 13N97W to 15N96W. The wave
has slowed down in motion to around 10 kt. The wave remains under
a rather broad and strong upper-level trough. This setup with
a pronounced diffluent flow pattern aloft continues to provide
favorable conditions for convection around and near the low and
tropical wave. Scattered moderate to isolated strong convection
is observed within 60 nm of low, and within 120 nm east of the
wave. Similar activity is to the west of the wave from 10N to
13N between 99W and 101W. This system is expected to attain
gradually development late in the week and into the weekend as
environmental conditions become more favorable.
..INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
The Monsoon Trough axis extends from 08N79W to 09N88W to low
pressure near 09N97W 1008 MB to 10N105W to low pressure near
11N110W 1010 MB to 13N120W to low pressure near 09N132W 1008 MB to
beyond 08N140W. Numerous strong convection is within 30 NM OF
13N122W. Scattered strong convection is within 120 NM south of
trough between 120W-124W. Scattered moderate to strong convection
is within 180 NM south of trough between 78W and 82W, and between
87W and 92W. Scattered moderate to isolated strong convection is
within 120 NM north of the trough between 107W and 111W, and also
within 120 NM south of the trough between 124W and 130W. Scattered
moderate convection is within 120 NM north of the axis between
130W and 134W.
N of 15N E of 120W:
A trough oriented from NNW to SSE will stay over the Baja
California peninsula this week. Light to gentle south winds will
continue over the Gulf waters through Wed, then winds will
increase to between gentle and moderate Thu through Sat.
A surface trough is analyzed from 29N122W to 23N123W. The
trough is situated just along the southeast periphery of a
northwest to southeast ridge axis extending roughly from
32N135W to near 25N124W. Light to moderate anticyclonic winds
surround the high and ridge across the waters W of 105W.
Strong north to northeast winds of 20 to 25 kt are pulsing across
the Gulf of Tehuantepec. A weaker repeat performance is expected
again tonight. Seas of 8 to 9 ft are anticipated as the resultant
NE wind wave mixes with long period SW swell. Fresh N to NE winds
tonight will cause seas to build to just 8 ft.
S of 15N E of 120W:
Moderate monsoonal winds prevail S of the monsoon trough, while
gentle to moderate northeast to east winds are observed N of the
Gulf of Papagayo gap winds of 20 to 25 kt from the NE to E are
expected early this morning and again tonight with seas topping
out at 8 ft. Weaker gap winds between 15 and 20 kt from the NE to
E are expected in the Gulf of Papagayo each night from Thu night
through Sat night. Combined seas should remain below 8 ft during
this time frame.
Long period SW swell are maintaining combined seas of 8 to 10 ft
to the W of 93W. The SW swell have begun to subside but will
continue to travel NE and mix with the N and NE swells
propagating out of the gap areas through Thu night. Seas W of 93W
will fall below 8 ft on Fri.
W of 120W:
A broad ridge dominates the EPAC waters N of 15N and W of 125W. A
area of 7 to 9 ft seas dominated by NE swell is observed N of 22N
between 124W and 132W. The area of higher seas will spread SW and
cover an area within 150 nm of a line from 30N129W to 21N140W by
early on Thu. These conditions will persist through Sat morning.
Long period cross-equatorial SW swell have begun to subside but
are maintaining seas of 8 to 9 south of 10N and east of 127W.
This area of swell will gradually decrease in size through Friday
with seas to 8 ft.