Tropical Weather Discussion
Issued by NWS
Issued by NWS
265 AXPZ20 KNHC 070713 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Sun Dec 7 2025 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 0600 UTC surface analysis and satellite imagery through 0700 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: Light and variable winds and slight to moderate seas will persist in the Gulf of Tehuantepec through the remainder of the weekend under a weak pressure pattern. By early in the week, a cold front will move through the Gulf of America with high pressure surging in across eastern Mexico in the wake of the front. Fresh to strong northerly winds will setup in the Gulf of Tehuantepec early Mon, then increase to gale-force Mon evening. Gale-force winds will then likely persist through at least Tue morning. These winds will build seas to rough Mon evening, peaking around 11 ft late Mon night into early Tue. Please refer to the latest NHC Pacific High Seas Forecast under the AWIPS header MIAHSFEP2 and under the WMO Header FZPN03 KNHC and at website https://www.hurricanes.gov/text/MIAHSFEP2.shtml for more details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from the SW Caribbean Sea to across Costa Rica to the Pacific coast at 09.5N84W to 07N93W to 11N111W to 08N123.5W. The ITCZ continues from 08N123.5W to beyond 07.5N140W. Scattered moderate isolated strong convection is noted from 08N to 14N between 111W and 120W. Scattered moderate convection is noted from 09.5N to 12N between 105W and 109W, from 09N to 11N between 126W and 128.5W, and from 06N to 09N between 135W and 140W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please refer to the Special Features section for details on a developing Gulf of Tehuantepec Gale Warning. A surface trough is analyzed from W of Las Marias Islands near 23N107W to near 19N110W. This trough is a reflection of an upper-level trough. Nearby deep convection has diminished and is more isolated in nature compared to several hours ago per the latest conventional infrared satellite imagery. Otherwise, a ridge dominates the offshore forecast waters of Baja California producing mainly gentle to moderate NW to N winds to the W of 109W, and light and variable winds E of 109W offshore SW and southern Mexico per recent ASCAT scatterometer data. Seas are mainly moderate across the offshore waters of Mexico. In the Gulf of California, gentle to moderate northerly winds prevail, mainly across the central part of the Gulf where seas are slight. For the forecast, occasionally fresh NW to N winds are expected in the central Gulf of California through Tue due to the pressure gradient between a trough over NW Mexico and a ridge offshore the Baja California peninsula. Looking ahead, the next gap wind event in the Gulf of Tehuantepec is expected to begin on Mon as a cold front moves over the Gulf of America and high pressure builds across the eastern slopes of the Sierra Madre mountains in the wake of the front. Strong to minimal gale force winds and rough seas are forecast with this event Mon night through Tue at least Tue. Fresh N winds may develop near Cabo Corrientes Tue night through Wed night. ...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Light to gentle winds prevail N of 06N with moderate southerly winds S of 06N per overnight ASCAT scatterometer passes. Seas are mainly moderate in mixed SW and NW swell, except slight nearshore Colombia northward. For the forecast, mainly gentle winds will prevail N of the monsoon trough through the next several days, except increasing and pulsing to moderate to fresh in the Gulf of Papagayo beginning early Tue. Gentle to moderate winds will prevail S of monsoon trough. Seas generated by a gap wind event in the Gulf of Tehuantepec are expected to spread across the outer offshore waters of El Salvador and Guatemala Tue and Tue night. Otherwise, moderate seas in mixed SW and NW swell are expected over the regional waters through at least the middle of the week. ...REMAINDER OF THE AREA... A high pressure system located N of area and the associated ridge dominates the waters N of the monsoon trough/ITCZ and W of 110W. Recent ASCAT scatterometer data showed moderate to locally fresh winds N of the ITCZ to 26N and W of 120W, while altimeter data showed seas of 6-9 ft over this region. Gentle to moderate winds prevail elsewhere including S of the monsoon trough/ITCZ. Seas of 4-7 ft prevail across the remainder of the open waters, dominated by long period NW swell. For the forecast, high pressure will remain in control of the weather pattern across the waters N of the monsoon trough/ITCZ and W of 110W through at least early in the week supporting moderate to locally fresh trade winds. Mainly gentle to moderate winds will prevail elsewhere, except locally fresh S of the monsoon trough and W of 100W at times. Rough seas will persist in the western waters for the remainder of this weekend into early week. Moderate seas are expected elsewhere over the eastern Pacific. Looking ahead, a new set of long period NW swell is forecast to reach the NW part of the forecast region by the middle of the week. $$ Lewitsky