AXPZ20 KNHC 301627 CCA
Tropical Weather Discussion...corrected
NWS National Hurricane Center Miami FL
1605 UTC Thu Jun 30 2016
corrected ITCZ/MONSOON TROUGH section
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
..INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...corrected
The monsoon trough extends from 09N79W to 09N92W to low pressure
near 10N101W 1010 mb to low pressure near 13N114W 1011 mb to
14N124W to low pressure near 14N126W 1010 mb to low pressure
near 12N132W 1008 mb to low pressure near 09N135W 1011 mb to
beyond 06N140W. Numerous moderate to strong convection is seen
from 04N to 08N between 77W and 82W. Scattered moderate to
strong convection exists from 10N to 15N between 93W and 102W.
Scattered strong convection is within 30 nm of axis between 89W
and 92W, and also between 120W and 121W.
N of 15N E of 120W:
A NNW to SSE oriented trough will remain over the Baja California
peninsula and northern Gulf of California through this weekend.
The trough will maintain gentle to moderate S flow across the
Northwest swell generated by strong to gale force winds along
the California coast will cause seas N of 26N and W of 118W to
build to between 8 and 9 ft on Sat. The swell will begin to
subside on Sat night, and allow for seas in this area to subside
to less than 8 ft on Sun.
A high pressure ridge extends southeastward from 23N120W to
18N109W. Gentle anticyclonic winds are noted in the vicinity of
the ridge from 20N to 25N between 110W and 120W.
Fresh north to northeast winds are pulsing across the Gulf of
Tehuantepec this morning. Resultant seas of 8 ft are due to
northeast wind waves mixing with long period SW swell. The winds
will become light and variable by this evening with seas subsiding
to just under 8 ft. Winds will then become briefly become fresh
north to northeast in the mornings each day through Saturday and
light and variable in the afternoons.
S of 15N E of 120W:
Gentle to moderate monsoonal flow prevails S of the monsoon
trough, while gentle to moderate NE to E winds are observed N of
the monsoon trough.
Fresh NE winds are occurring through the Gulf of Papagayo, and
west to 91W with seas to 8 ft as the NE wind waves mix with SW
swell. Lighter winds and seas less than 8 ft are expected tonight
through Saturday. A similar gap wind event on Saturday could lead
to seas to again build to 8 ft in the Gulf of Papagayo.
Long period SW swell mixing with smaller swell components are
maintaining combined seas just above 8 ft from 02N to 15N between
94W and 112W, and from 05N to 11N between 90W and 94W as indicated
a recent altimeter pass. The swell energy is forecast by
wavewatch guidance to gradually dissipate through early Saturday
afternoon allowing for seas to subside to less than 8 ft.
Numerical model guidance continues to suggest that the low
pressure near 10N101W will become better organized by late on
Friday under more favorable upper level atmospheric conditions.
The low is forecast to gradually strengthen while tracking in a
general west to west-northwestward direction through the weekend.
W of 120W:
A broad ridge dominates the EPAC waters N of 15N. A swath of 7 to
9 ft seas dominated by NE swell is observed within 150 nm either
side of a line from 30N129W to 21N136W. These conditions will
spread SW through tonight. A reinforcing surge of large N swell
will allow for seas north of 24N to build to between 8 and 10 ft
on Sat. These swell will begin to subside on Sat night and allow
seas in this area to drop below 8 ft by Mon.