AXPZ20 KNHC 071603
Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1410 UTC Sat Dec 7 2019
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
Gulf of Tehuantepec Gale Warning: A cold front extending across
the W Gulf of Mexico to near Tampico Mexico will continue moving
SE today. High pressure is currently building S over eastern
Mexico into the Tehuantepec region. The enhanced N to S pressure
gradient is supporting minimal gale force N to NE gap winds over
the Gulf of Tehuantepec, which will continue through tonight.
Seas will peak between 12 and 13 ft downstream of the Gulf
tonight, then subside Sun as the pressure gradient weakens and
wind speeds diminish to fresh to strong speeds. Looking ahead,
another gale force gap wind event could affect the Gulf of
Tehuantepec Wed into Thu as a stronger cold front crosses the
Gulf of Mexico.
See latest NWS High Seas Forecast issued by National Hurricane
Center under AWIPS/WMO headers HSFEP2/FZPN03 KNHC or at website
https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml for more details.
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
The monsoon trough extends from 09N74W to 08N88W to 07N100W. The
ITCZ continues from 07N100W to 07N109W then resumes from 06N113W
to 08N120W to 06N130W. Scattered moderate and isolated strong
convection is present within 90 nm either side of the monsoon
trough axis W of Colombia and within 90 nm either side of the
ITCZ axis E of 104W.
OFFSHORE WATERS WITHIN 250 NM OF MEXICO...
Fresh to locally strong NW winds continue over the central and
southern Gulf of California between a low pressure trough passing
over the Mouth of the Gulf of California and Sonora Mexico and a
weak high pressure ridge over the Baja California offshore
waters. These winds will persist today, then diminish to
moderate speeds on Sun. Peak seas are currently peaking around 6
ft across southern portions of the Gulf and will gradually
subside through Mon. Elsewhere, gentle winds prevail across most
of the offshore waters, as weak high pressure resides over the
waters W of Baja to around 125W. A weakening cold front is
pushing slowly SE across the far NW waters approaching 125W.
Elsewhere across the Mexican offshore waters, variable and gentle
winds prevail, except for increasing northerly gap winds over
the Gulf of Tehuantepec. Please see the Special Features section
above for more details on the Gulf of Tehuantepec Gale Warning.
Large NW swell will enter the Baja California Norte waters today,
with offshore seas building to between 8 and 11 ft by tonight.
This swell will continue spreading SE across the region tonight
through Sun night, then decay Mon and Mon night. A high pressure
ridge will build across the northern waters Sun night and Mon,
which will result in freshening N winds offshore and over the
Gulf of California through early next week.
OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND
WITHIN 750 NM OF ECUADOR...
The latest GOES-16 satellite imagery shows scattered moderate to
strong convection continues along the monsoon trough from S of
the Gulf of Tehuantepec to off the coast of Colombia. This
weather is expected to continue shifting westward today.
Strong NE to E winds will pulse to around 25 kt each night
across and downstream of the Gulf of Papagayo through Tue, with
seas peaking between 8 and 9 ft downstream of the Gulf each
morning. Elsewhere, gentle to moderate S to SW monsoon flow will
persist across the offshore waters of Costa Rica, Panama,
Colombia, and Ecuador during the next several days.
REMAINDER OF THE AREA...
A weakening cold front extends from 30N124W to 26N130W to
23N140W. Scattered moderate convection is evident in satellite
imagery behind the front in the vicinity of a trough extending
from 30N133W to 27N140W. Large NW swell associated with the
weakening front is spreading across the region, as seas greater
than 12 ft dominate the waters NW of the front. Recent altimeter
data suggests seas as high as 17 ft near 30N136W. This front
will continue slowly moving eastward across the northern waters
tonight, then weaken and dissipate as it crosses 120W today and
tonight. Large NW swell will continue propagating SE through the
weekend. Seas will remain greater than 12 ft over the northern
waters today, then subside tonight and Sun.
Looking ahead, another cold front will approach the NW portion of
the discussion area Mon and introduce new NW swell into the NW
waters through the middle of next week.