AXPZ20 KNHC 080359

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0405 UTC Mon Mar 08 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 meteorological analysis.

Based on 0000 UTC surface analysis and satellite imagery through 0345 UTC.


Gulf of Tehuantepec Gale Warning: Strong high pressure building southward over eastern Mexico and the Gulf of Mexico is supporting a gap wind event in the Tehuantepec region. Strong gale force N to NE winds will continue through Tue, then diminish to minimal gale force Tue night through early Wed. Presently, seas are in the range of 10-14 ft with these winds. These seas are forecast to build to 12-18 Mon afternoon, before they begin to subside through Wed night. Mariners transiting this region should exercise caution to avoid possible hazardous conditions that may result from this event. Please read the latest NWS High Seas Forecast issued by the National Hurricane Center at website: https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml for more details.


A trough extends from a 1008 mb low over northern Colombia southwestward to the coast of Colombia at 06N78W and continues to 03N80W to 06N87W and to 04N96W, where latest scatterometer data indicates it transitions to the ITCZ to 04N110W to 02N122W to 03N135W and to beyond the area at 03N140W. Scattered moderate convection is within 30 nm of the ITCZ between 99W-101W.


See the Special Features section above regarding an ongoing Gale Warning for the Gulf of Tehuantepec region.

Moderate to fresh NW winds will remain west of the Baja California peninsula through Tue, then increase to fresh to strong speeds Tue night north of Cabo San Lazaro shifting to south of Cabo San Lazaro Thu and Thu night. Large NW swell west of Baja California that is producing seas of 8-9 ft will gradually through Mon. A second set of large NW swell will begin to impact the forecast waters Mon evening, and continue through Sun, inducing seas in the range of 8-12 ft through the offshore waters.

Light to gentle variable winds in the Gulf of California will shift to NW to N moderate to locally fresh early on Wed. Moderate to fresh winds along the southern half of the Gulf of California will increase to fresh to strong Fri evening. Otherwise, gentle to moderate winds will prevail over the offshore waters west of southern Mexico, except in the vicinity of the Gulf of Tehuantepec.


Fresh to strong NE to E winds will continue across the Papagayo region through the end of the week, with winds possibly reaching to near gale force late tonight into Mon. Seas associated with these winds will build to 8-11 ft through Mon as strong high pressure builds over the western Caribbean Sea. Fresh to locally strong northerly winds are forecast in the Gulf of Panama through Wed, with the locally strong winds expected mainly through early Mon. Sea downwind from these winds will build to a maximum of 8 ft Sun night into Mon morning, then subside to about 6 ft Mon night through Wed. Light to gentle winds along with seas in the 3-5 ft range due to a S to SW swell will prevail elsewhere through the middle part of the week.

Moist westerly flow south of the trough described above under ITCZ/MONSOON TROUGH has helped de-stabilize the environment offshore and inland Colombia. GOES-16 Satellite imagery reveals increased cloudiness there along with recently developed scattered showers and isolated thunderstorms roughly from 01N to 05N E of 79W to inland Colombia. The activity inland Colombia has become of the numerous moderate to isolated strong type this evening. Locally heavy rains can be expected with this activity.


Strong high pressure ridging stretches east-southeastward to near 18N106W. The gradient between this ridge and lower pressure S of 20N is supporting fresh to locally strong NE to E winds between the ITCZ and 20N and W of about 125W. Seas within this area are in the 8-11 ft range due to long-period NW to N swell, except for higher seas of 10-13 ft from 09N to 11N between 132W-136W. This area of swell will gradually shift SE through the early part of the week as a new cold front moves into the NW part of the area.

A new set of long-period NW to N swell is entering the NW forecast waters. It is producing seas of 8-10 ft. This set of swell will gradually propagate as far S as 03N and W of about 112W by late mid-week as the area of trade winds expands some to the N. By mid-week, yet another set of NW to N swell will be moving through the northern waters, where even higher seas peaking to around 14 ft are expected, before subsiding at the end of the week.

$$ Aguirre