AXPZ20 KNHC 151508
Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1605 UTC Thu Apr 15 2021
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...
A surface trough extends from a 1009 mb low pressure located
over northern Colombia near 09N76W to 07N102W. The ITCZ
continues from 07N102W to 06N120W to beyond 02N140W. A surface
trough is analyzed within the ITCZ and extends from 09N125W to
03N127W. A large cluster of moderate to strong convection is seen
from 02N-09N between 81W-86W. Scattered moderate isolated strong
convection can be found from 03N-08N between 110W-118W, and near
the trough axis from 04N-09N between 121W-130W. Similar convection
is N of the trough axis from 07N-10N between 95W-102W.
OFFSHORE WATERS WITHIN 250 NM OF MEXICO...
A broad ridge dominates the offshore forecast waters of Baja
California and extends southeast across the regional waters to
near 15N108W. The pressure gradient between the ridge and a
meandering trough over the Gulf of California is supporting
moderate to locally fresh northerly winds west of the Baja
California peninsula. Gentle to moderate northwest to west winds
prevail elsewhere across the open offshore waters south of Baja
to the waters south of Puerto Angel. NW swell off Baja California
Norte is presently producing seas of 6-7 ft that will gradually
subside to 5-6 ft on Fri. Winds will increase slightly N of Cabo
San Lazaro Fri night through Sat night as the high pressure
shifts southward to near 31N.
Gulf of California: Mainly light to gentle winds will prevail
across the Gulf of California over the next several days, with
the exception of moderate NW winds over the northern part of the
Gulf today. Increasing westerly winds of 20-25 kt are expected
over northern Mexico and E of the Sierra Madre Occidental this
evening, and again Fri evening.
Gulf of Tehuantepec: mainly gentle W-NW winds will prevail across
the Tehuantepec region this week. The GFS Model suggests a brief
gap wind event in the Gulf of Tehuantepec Sun night into Mon
morning as a cold front moves across the western Gulf of Mexico.
Northerly winds of 20-25 kt winds and seas in the 4-6 ft range
are presently expected.
OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, and
WITHIN 750 NM OF ECUADOR...
Light to gentle winds prevail across the forecast area, except
for fresh to locally strong offshore gap winds across the
Papagayo region this morning with seas of 6-7 ft. Little change
in wind conditions are expected through through Fri. Moderate
sized SW swell moving into the regional waters will dominate the
offshore waters through Fri.
As previously mentioned, a large cluster of moderate to strong
convection is occurring mostly over water from 02N-09N between
81W-86W. Upper atmospheric conditions are currently favorable
for any convection that develops across the area to become
strong, and capable of producing torrential rainfall and strong
gusty winds. Look for strong thunderstorm activity to prevail
across the area east of 95W through Sat night before upper level
conditions start to stabilize.
REMAINDER OF THE AREA...
High pressure dominates the northern forecast waters mainly N of
15N and W of 110W. The pressure gradient between this system and
lower pressure in the vicinity of the ITCZ is supporting
moderate to locally fresh NE-E winds to the north of the ITCZ to
22N and west of 120W. Seas are in the 6-8 ft range across the
tradewind belt south of 20N. Elsewhere, gentle to moderate winds
prevail, except for fresh southerly winds across the far
northwestern waters, as low pressure persists to the west of
140W. This persistent low pressure will finally lift northward
and just beyond the NW waters on Fri. This will allow high
pressure to sink southward to along 31N late Thu through Sat. The
pressure gradient between the high and the ITCZ will tighten and
act to freshen winds north of the ITCZ and west of 124W late Fri
into the weekend. Seas there will build 7-9 ft.