Tropical Weather Discussion
Tropical Weather Discussion NWS National Hurricane Center Miami FL 1544 UTC Tue Jan 23 2018 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 1545 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: Strong winds will increase to gale force this evening, with a continuous period of sustained gale force winds expected over the Gulf until Fri. Winds should peak Thu with maximum seas of 17 ft. Propagating N to NE swell will cause seas to build to 8 ft or greater as far S as 07N and as far W as 110W by Fri morning. Strong winds over the Gulf should diminish briefly Sat evening as high pres centered over the SE United States shifts E into the western Atlc. Another gale is possible late in the weekend as a strong cold front crosses the western Gulf of Mexico. Please refer to the East Pacific High Seas Forecast under AWIPS/WMO headers HSFEP2/FZPN03 KNHC for more details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A surface trough extends from 10N74W to 06N80W to 06N95W. The ITCZ continues from 06N95W to 06N115W to beyond 07N140W. Scattered moderate with isolated strong convection is from 03N to 08N between 76W and 80W. Scattered moderate convection is from 08N to 13N between 127W and 140W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Gulf of Tehuantepec: Please refer to the special features section above. Gulf of California: Fresh to strong winds are expected across the Gulf through tonight before diminishing by Wed evening as high pres to the north is weakened by low pres moving into the NW United States. Winds will increase once again this weekend as high pressure builds to the northwest of the region. Decaying NW swell are still maintaining seas of 8 to 10 ft off the coast of the Baja California Peninsula. This large swell is producing high surf along the coasts and outer reefs of Baja California and mainland Mexico. The area of seas greater than 8 ft will slowly subside through Wed. Then, a fresh set of NW swell will propagate into the waters off the coast of Baja California Norte Thu night. Seas associated with this swell will peak near 12 ft Fri. Meanwhile, fresh to strong NW winds are expected off the far NW waters of Baja California Norte late this week as high pressure builds east toward the region. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Nocturnal winds will pulse to strong each night tonight through Fri night as high pres ridges SE from the Gulf of Mexico over the NW Caribbean. Elsewhere N of 09N, light to gentle offshore flow will prevail. Gentle southerly winds will prevail S of 09N for the next few days. REMAINDER OF THE AREA... The pressure gradient between high pressure centered just N of the 30N and lower pressure in the vicinity of the ITCZ is supporting fresh to strong winds from the ITCZ north to 21N and west of 115W with peak seas of 12 ft, as confirmed by a pair of recent altimeter passes. Combined seas of 12 ft or greater will continue to prevail within the region of stronger trade winds that are currently from 10N to 18N W of 120W, in a mix of dominant long period NW swell and short period NE wind waves. Seas 8 ft or greater cover nearly all the the open waters N of 05N and west of 106W. The area of fresh to strong trades and 12 ft seas prevailing north of the ITCZ will gradually erode westward through early Wed as high pres N of the forecast waters weakens, as a cold front crosses the NW waters. High pressure building back in behind the cold front will once again cause the coverage of the fresh to strong trades to increase early Thu through Fri night.