AXPZ20 KNHC 261525

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1525 UTC Tue Mar 26 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 meteorological analysis.

Based on 1200 UTC surface analysis and satellite imagery through 1500 UTC.


Gulf of Tehuantepec Gale Warning: A strong north to south pressure gradient has developed over southern Mexico this morning as high pressure builds across the western Gulf of Mexico. This is likely supporting gale force gap winds funneling through the Chivela Pass. North to northeast gales are expected to persist through Thu morning as high pressure continues building southward across eastern Mexico behind a cold front. Wind speeds will approach strong gale force during the late night and early morning hours. Wave heights will peak around 18 ft on Wed morning, and NE swell generated by this event will propagate well downstream of the Gulf beyond 100W.

Please read the latest High Seas Forecast issued by the National Hurricane Center under AWIPS/WMO headers FZPN03 KNHC/HSFEP2 or at website https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml for further details.


A surface trough extends from the coast of Colombia near 07N78W to 06N86W. The ITCZ continues from 06N86W to 01.5N107W to 03N115W to 02N124W to 06N135W to beyond 06N140W. Scattered moderate convection is noted within 60 nm north of the ITCZ between 88W and 91W, within 45 nm of the ITCZ between 114W and 117W, and within 90 nm of the ITCZ between 129W and 138W.



Gulf of Tehuantepec: Please refer to the Special Features section above for more information on the Gale Warning currently in effect. Winds will diminish below gale force by Thu afternoon and become gentle into the weekend as high pressure moves away from the region.

Gulf of California: Relatively tranquil conditions will prevail through the week with winds generally less than 15 kt and seas ranging from 2-4 ft. NW to N winds over the southern Gulf of California may reach fresh speeds on Fri night as high pressure begins building over the Great Basin.

Overnight scatterometer data showed moderate NW to N winds over the offshore waters west of the Baja Peninsula. Moderate northerly flow will persist over this region through Wed night as high pressure weakens west of Baja California Norte. Residual NW swell over the region will continue decaying through tonight with seas less than 8 ft throughout by Wed. A stronger high pressure system will build toward the region on Thu. Fresh to strong NW to N winds are expected in the Baja California Norte offshore waters from Thu night through Fri night with seas building to 8-11 ft.


Gulf of Papagayo: Strong to near gale force NE to E winds will continue pulsing over the Gulf of Papagayo through Fri. The strongest winds will occur during the late night and early morning hours as nocturnal drainage flow enhances wind speeds. Seas will build to 11 ft Wed and Thu, and associated NE swell will propagate well downstream from the Gulf of Papagayo through Friday night. Looking ahead, wind speeds will diminish to fresh to strong speeds by the weekend.

Gulf of Panama: Moderate to fresh N to NE winds in the Gulf of Panama will strengthen to fresh to strong speeds late tonight and persist through Wed night. For Thu through Sat night, moderate to fresh winds will prevail across the Gulf of Panama. A combination of NE wind waves and cross-equatorial SW swell will create 6-8 ft seas downstream of the Gulf Wed through Fri night.

Southern hemisphere swell will continue to impact the region between Ecuador and the Galapagos Islands through the end of the week. Seas will build to 8 ft south of the Galapagos by Wed as another set of long period SW swell crosses the region. Light to moderate winds will prevail this week.


A stationary front extends from 30N127W to 25N134W this morning. Meanwhile, another cold front is approaching the far northern waters and is expected to move into the far NW portion of the forecast area by tonight. NW swell associated with these features will impact the northern waters through midweek. Another cold front will stall just NW of the forecast area on Fri. The associated NW swell will move into the NW waters late Thu and propagate eastward to 120W by Sat.

The pressure gradient between high pressure near 28N123W and the ITCZ is supporting moderate to fresh NE to E trade winds based on overnight scatterometer data. Available altimeter data suggests 8-11 ft seas are found from roughly 03N to 20N west of 110W, likely a combined result of long period NW swell and shorter period NE wind waves. These trade winds will diminish briefly tonight and Wed, then strengthen beginning Thu as stronger high pressure builds north of 30N. Looking ahead, fresh to strong trade winds will prevail Thu through Sat with perhaps near gale winds developing west of 135W on Fri.

Elsewhere, NW swell propagating across the high seas domain is maintaining seas of 8 ft or greater in the waters generally north of the Equator and west of 105W. The NE swell generated by the gap winds in the Gulf of Papagayo and the Gulf of Tehuantepec will merge with NW swell and long period cross-equatorial S to SW swell today through Fri night. This will result in a large swath of 8-10 ft seas encompassing an area generally south of 15N and west of 92W to beyond 140W during the later part of the week.

$$ Reinhart