


Tropical Weather Discussion
Issued by NWS
Issued by NWS
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004 AXPZ20 KNHC 172005 CCA TWDEP Tropical Weather Discussion...Corrected NWS National Hurricane Center Miami FL 1845 UTC Thu Apr 17 2025 Corrected forecast for Offshore Waters Within 250 nm of Mexico Tropical Weather Discussion for the eastern Pacific Ocean from 03.4S to 30N, east of 120W including the Gulf of California, and from the Equator to 30N, between 120W and 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 1830 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A trough axis extends from low pressure in northwest Colombia to 09N84W to 08N88W to 06N93W, where it transitions to the ITCZ to 05N102W to 06N112W to 06N120W to 06N125W. Scattered moderate to strong convection is from 03N to 06N between 86W-89W, and within 180 nm south of the trough between 84W-86W. Scattered moderate to isolated strong convection is within 120 nm south of the ITCZ between 105W-112W, within 120 nm north of the ITCZ between 115W-120W, within 120 nm north of the ITCZ between 115W-120W, also within 60 nm south of the ITCZ between 102W-105W and between 112W-115W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO...Corrected The gradient associated to high pressure that extends from the Gulf of America southwestward to southeastern Mexico continues to support strong to near gale north winds in the Gulf of Tehuantepec extending south to near 14N as seen an overnight scatterometer satellite data pass. Peak seas with these winds are around 9 ft. Deep-layer low pressure offshore of southern California is producing a weak surface low there, with an elongated trough extending southwestward to near 29N130W. This area of low pressure is blocking high pressure farther NW from building unobstructed into the Baja waters. However, this high pressure does extend a weak ridge eastward and below the surface trough to Baja Sur. The associated pressure gradient between this ridge and lower pressure across the Gulf of California is supporting gentle winds across the waters of Baja Norte, and moderate to locally fresh northwest to north winds across the Baja waters south of Punta Eugenia becoming northerly across the Revillagigedo Islands. Seas are 4 to 5 ft N of Punta Eugenia and 5 to 7 ft southward to the Revillagigedo Islands. Elsewhere over the Pacific offshore waters, winds are moderate or weaker with seas of 4-5 ft in mixed NW and S swell. The Santa Maria Volcano located in southwestern Guatemala near 14.8N91.6W is presently undergoing continuous volcanic ash emissions. The volcanic ash near the volcano is moving to southwest. Latest GOES-E satellite imagery shows resultant hazy skies along the coast of Guatemala, with similar conditions just offshore the coast. Reduced visibility is presently more likely to be near the coast. Mariners are encouraged to be aware of the latest updates on the status of this volcano. In the Gulf of California, southwest to west winds in the northern section of the Gulf that earlier were at gale-force have recently diminished to strong speeds along with seas to around 8 ft. These winds will diminish further, to 15 kt or less, this afternoon. Winds will gradually diminish there through Fri, except becoming fresh to strong from the southwest Fri night. High pressure extends across Baja and northwestern Mexico tonight ahead of a strong frontal system developing across the western U.S., and will also induce westerly gap winds each of the next few nights across central portions of the Gulf, peaking at strong speeds. Gentle winds will continue in the southern section of the Gulf through Sat along with seas of 2 to 4 ft. For the forecast, winds over the northern Gulf of California are expected to again pulse to strong to near gale-force tonight. Fresh to locally strong W gap winds will also develop during this time across central portions of the Gulf. Strong to near gale-force north winds in the Gulf of Tehuantepec will gradually diminish today before the gap wind flow ends there tonight. Elsewhere, winds across the Mexican Offshore zones will remain moderate or weaker north of Punta Eugenia, and moderate to fresh off Baja California Sur through Sat night, then become moderate to locally fresh north of 20N Sun afternoon through Mon. ...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... High pressure across the central Atlantic and eastern Gulf of America extending into the NW Caribbean is inducing gap winds across the Pacific waters of Central America, and fresh to locally strong NE to E gap winds across the Papagayo region tonight. Seas are currently 5 to 8 ft there. NE winds across the southwestern Caribbean are producing fresh N winds over the Gulf of Panama extending to 06N, where seas are 4 to 6 ft. Elsewhere, between Ecuador and the Galapagos Islands, winds are gentle to moderate with 4-6 ft seas in S swell. Large clusters of scattered to numerous showers and thunderstorms continue to shift westward across the waters south of 08N, moving offshore northern Ecuador and Colombia and passing along the Pacific coasts and waters of Panama and Costa Rica east of 90W. The strongest of the thunderstorms have the potential to produce wind gusts to gale force and locally rough seas. For the forecast, the surface ridge over the eastern Gulf of America that extends into the northwestern Caribbean will shift gradually eastward to the Atlantic waters between Cape Hatteras and Bermuda during the next several days to support fresh to strong NE to E gap winds across the Papagayo region, pulsing to near 30 kt at night through Sat night, then diminish slightly through Mon night. The same high pressure will force moderate to fresh N winds across the Gulf of Panama to near 5N through Sat night along with peak seas to around 6 ft. Locally strong N to NE winds are expected in the Gulf of Panama tonight and Fri night. Moderate SW swell will move into the regional waters Mon. ...REMAINDER OF THE AREA.... A modest surface ridge dominates the waters W of 130W tonight, and extends a ridge south then weakly eastward over the subtropical waters west of the Baja California Sur waters, to the south of a surface trough extending from offshore of southern California to near 29N130W. A trough is located just west of the ITCZ from 02N129W to 02N129W. Scattered moderate to isolated strong convection is noted west of the trough to 130W and from 04N to 07N. This pattern continues to produce moderate to locally fresh NE winds between the ITCZ and 21N, W of 125W per overnight scatterometer satellite data passes. Seas in this region are 7-8 ft in N swell. N of 21N, gentle to moderate N to NE winds prevail, with seas of 5 to 7 ft in mixed NW and NE swell. S of 20N between 100W and 125W, moderate to locally fresh trade winds prevail, with seas of 5 to 8 ft in mixed N and E swell. Scattered moderate isolated strong convection is occurring near the ITCZ to 08N. For the forecast, little change in the winds across the open waters is expected for the next several days, except for slightly stronger trades occurring W of 120W over the weekend. The persistence of these winds will lead to building seas of 8 to 9 ft, subsiding Mon. Otherwise, new moderate northerly swell is forecast to reach the far northern waters west of the Baja California Peninsula Mon, building seas to around 8 ft. $$ Aguirre