Tropical Weather Discussion
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AXPZ20 KNHC 182154

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
2205 UTC Sun Mar 18 2018

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
2145 UTC.


Gale Warning: An initial cold front over the far northwest
portion of the discussion area is preceded by strong southerly
flow with seas of 7 to 9 ft. A deepening surface low pres
currently well northwest of the area will drop southeastward to
near 32N140W on Mon night behind this initial cold front, and
drag a second cold front into the discussion area accompanied by
a strong to near gale southwest-west-northwest wind shift. The
pressure gradient will tighten around the southwest semicircle
of the low increasing the westerly winds to 25 to 35 kt minimal
gale force across the discussion waters from 29N to 30N west of
139W at 0900 UTC on Tue, with the associated seas of 12 to 18 ft
forecast from 26N to 32N between 136W and 140W. The low pres
will lift north of the area on Tue night with associated winds
diminishing to 20 kt or less south of 32N on Wed evening. The
associated northwest swell, in the form of 7 to 10 ft seas, will
propagate southeast across the discussion waters covering the
area west of a line from the Central Baja peninsula to 06N140W
on Sat. Please refer to the Pacific high seas forecast for more
details on this upcoming event under AWIPS/WMO headers


A surface trough is analyzed from 08N82W to 05N101W where
scatterometer winds indicate an ITCZ develops, and continues W
to beyond 05N140W. Scattered moderate isolated strong convection
is noted within 150 nm of 05.5N85W and within 30 nm of lines
from 10.5N116.5W to 09.6N123W and from 04N121.5W to 05.5N130W.



A north-northwest to south-southeast ridge extending from
30N121W to 17N110W to 13N94W will shift slightly southwest on
Mon and Tue. Fresh to locally strong northerly winds will set up
south of 25N and east of the ridge briefly on Mon and Mon night
with the pressure gradient then relaxing some on Tue. Light to
gentle northerly winds and 2 to 4 ft seas are then expected west
of the Baja Peninsula through Thu night, with large northwest
swells arriving at 30N120W on Fri.

Gulf of California: Moderate to fresh northwest flow is forecast
across the entire gulf waters tonight through Mon, with narrow
swaths of strong northwest winds expected across the far
southern gulf waters late Mon. Seas may build to 6 ft in the
longer fetch waters.

Fresh to locally strong northwest to north flow expected across
the open Pacific waters from 18N to 23N east of 110W through
late Mon night with seas building to 8 ft.

Gulf of Tehuantepec: Strong north flow will surge through the
gulf waters on Tue evening, increasing to minimal gale force
late Wed. Gale conditions are then expected to continue through
Thu morning, with seas building to 13 ft downstream near
14.5N95.5W on Wed night.


Gulf of Papagayo: Fresh to locally strong NE nocturnal winds
expected tonight and again briefly on Tue night with seas
building to 7 ft downstream.  A stronger drainage event is
forecast to begin on Wed night, and persist into the upcoming

Gulf of Panama: Fresh northerly winds are expected tonight.
Fresh to strong north nocturnal winds are expected to resume on
Wed night.

Elsewhere, gentle to moderate offshore flow will prevail N of
07N while light to gentle SW winds are forecast S of 07N.


Refer to the Special Features Section above.

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