000 AXPZ20 KNHC 250317 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0034 UTC Fri Jan 25 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 0000 UTC surface analysis and satellite imagery through 0300 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: The pressure gradient over SE Mexico has begun to slacken as high pressure ridging S over the Gulf from Louisiana slowly shifts E. However, high pres moving SE from the central plains will reinforce the ridge over the Gulf and allow NE to N gale force winds over the Gulf of Tehuantepec to spike back up to gale force later tonight through Sat morning. Thereafter, the ridge will shift toward the SE United States. Seas ranging between 9 and 14 ft tonight will gradually taper off through Sat, then will subside more rapidly as the current event shuts down. The area of 8 ft seas generated by this event will spread well to the S and SW of the Gulf as far as 10N100W tonight and Fri, then subside. Another strong cold front will be entering the Gulf of Mexico on Sunday. Gales will be possible over the basin again by Sun night. 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. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A surface trough extends SW from 1008 mb low pressure centered over NW Colombia near 10N75W to 03N81W to 05N87W. The ITCZ continues from to 05N87W to 02N94W to 06N108W to 08N126W. Scattered moderate convection is occurring from 10N to 21N between 130W and 139W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Gulf of California: Fresh to strong NW winds are occurring almost all of the basin. High pressure over the Great Basin will remain strong through Sat night and maintain the pressure gradient over the Gulf of California. Seas associated with these winds will peak around 8 ft. Elsewhere, high pressure to the N and NW of the area is supporting moderate to fresh northerly winds west of the Baja California peninsula. Winds will diminish across this area Fri night and Sat morning as the high weakens and shifts north. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo: Fresh to strong NE winds will continue pulsing across the Gulf of Papagayo through Sun afternoon. Seas in this area will peak around 8 ft on Fri morning. Gulf of Panama: Fresh N to NE winds will pulse over the Gulf will occur mainly at night and into the early afternoon through Sat. Winds could become locally strong Fri night. REMAINDER OF THE AREA... Broad 1032 mb high pressure centered well N of the area near 38N132W ridges across the forecast waters north of 10N. A surface trough curves NE from 05N138W through low pres 1007 mb near 09N134.5W to 13N133.5W. This trough breaks the ITCZ. The surface trough is receiving strong upper-level support from a mid to upper-level trough extending SSW from low pres near 30N137W to 20N143W to another low centered near 14N141W. The upper-level divergence on the E side of the trough is triggering a large area of scattered moderate convection from 10N to 21N between 130W and 139W. The pressure gradient between the ridge and the surface trough is generating fresh to strong trades between 10N and 20N W of 120W. Seas in this region are running between 8 and 12 ft. Model guidance suggests the strong dynamics E of the upper-level low will support additional development of the surface low during the next 24 hours, then the low will begin to weaken. The resultant fetch of winds could generate seas as high as 15 ft in this region. An extensive area of seas 8 to 11 ft in mixed NE and NW swell will cover the waters elsewhere generally N of 09N and W of 120W. This area of 8 ft seas will slowly retreat W to near 130W by Sun evening. $$ CAM