000 AXPZ20 KNHC 260304 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 042 UTC Sat Jan 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 0000 UTC surface analysis and satellite imagery through 0215 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: Reinforcing high pressure moving SE from the Central Plains has maintained the pressure gradient over SE Mexico and caused the N to NE winds over the Gulf of Tehuantepec to return to gale force. The gales will continue until around sunrise on Sat. Thereafter, the ridge will shift E toward the SE United States. Seas currently ranging between 8 and 12 ft will begin to subside Sat, then will subside to below 8 ft as the current gap wind 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 12N98W tonight, then subside. Another strong cold front will be entering the Gulf of Mexico on Sunday. Gales are expected to resume over the basin 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. Gale Warning for the Far Western Waters: A strong mid to upper- level low is centered near 15N139W. A trough extends SE from this low to near 10N133W. The upper-level low and trough are supporting a 1006 mb surface low centered near 15N132.5W and another 1008 mb low centered near 15.5N140W. Extensive tropical moisture feeding northward on the E side of this system is fueling scattered moderate and isolated strong convection within 90 nm either side of a line from 09N127W to 15N129W. Scattered moderate convection is occurring elsewhere from 09N to 20N between 124W and 132W. Scattered moderate and isolated strong convection is evident within 150 nm in the NE semicircle of the low centered near 15.5N140W. The easternmost low is forecast to lift N through Sun and will pull moisture and convection with it to beyond 20N. As the low moves N, the pressure gradient will also tighten between the high to the north and the low as it develops tonight. Gale force winds are expected to begin in the N and NE quadrants of the low within 150 nm before dawn Sat morning. Seas will build to between 10 and 15 ft during this time. This system will begin to weaken at all levels by Sat evening and allow winds and seas to gradually subside. Both lows will lose identity by Sun evening but leave an area of seas 8 ft or greater W of a line from 30N132W to 25N132W to 19N137W. This area of seas will subside below 8 ft by Sun night as the swell continue to decay. Please see 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... Surface trough from low pres 1008 mb near 08N74W to 06N86W. The ITCZ continues from 06N86W to 03N97W to 05N110W to 09N124W to 12N129W. No significant convection is currently associated with these features. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Gulf of California: Fresh to strong NW winds have subsided over all of the Gulf except between 27N and 29N. High pressure over the Great Basin will remain strong through Sun and combine with lower pressure along the western slopes of the Sierra Madre Occidental to maintain a tight pressure gradient. The strong NW winds over the Gulf of California will subside by Sun night as the Great Basin high weakens. Seas associated with these winds will remain below 8 ft. Elsewhere, high pressure ridging S from the waters adjacent to the United States West Coast is producing light to moderate N winds west of the Baja California Peninsula. This relatively light wind regime will persist through Tue as the weak ridge stays in place. 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 nightly across the Gulf of Papagayo through Sun, then increase once again on Tue. Seas in this area will peak around 9 ft Sat morning. Gulf of Panama: Fresh N to NE winds will pulse over the Gulf mainly at night through the early afternoon hours until Sat. Winds could become fresh again on Tue. REMAINDER OF THE AREA... Broad high pressure measuring 1035 mb is centered just off the coasts of Washington and Oregon near 46N127W. The high ridges S to cover all the forecast waters north of 10N and W of 110W. The pressure gradient between the ridge, ITCZ, and broad area of low pressure S of 20N and W of 125W is generating fresh to strong trades between 10N and 20N W of 115W. Seas in this region are running between 6 and 15 ft, highest to the E of the low. Model guidance suggests the area of fresh to strong winds will shift N this weekend in tandem with the low, but gradually diminishing in areal coverage Sat night and Sun as the low weakens. An extensive area of seas 8 to 11 ft in mixed northeast and northwest swell will cover the waters elsewhere generally N of 09N and W of 125W. This area of 8 ft seas will slowly retreat westward to near 130W by Sun evening. $$ CAM