000 AXPZ20 KNHC 230309 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 101 UTC Sun Dec 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 0000 UTC surface analysis and satellite imagery through 0300 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: Winds have diminished to 20-25 kt across the Tehuantepec region with seas to 8 ft. Winds will increase again on Sun, with gale conditions expected again in this area late Sun through Mon night as an area of high pressure builds southward over southern Mexico. The forecast calls for winds of 30-40 kt and seas of 10-14 ft on Sun night. Please refer to the latest high seas forecast issued under AWIPS/WMO headers HSFEP2/FZNPN03 for more specific marine details. Gulf of Papagayo Gale Warning: High pressure building southward over the northwestern Caribbean Sea is inducing a tight pressure gradient over northern Central America, which is resulting in minimal gale force winds over the Gulf of Papagayo tonight. These winds are forecast to diminish to below gale force by early Sun afternoon. Fresh to strong winds are then expected across the Gulf of Papagayo through at least the middle of next week. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A surface trough extends from the coast of Colombia near 06N77W to 07N85W and to 04N90W. The ITCZ continues from 04N90W to 07N113W, where it is interrupted by a surface trough along a position from 11N114W to 05N116W. The ITCZ resumes to the west of this trough at 07N118W and continues to 08N130W and to beyond 07N140W. Scattered moderate convection is from 06N to 09N W of 130W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see the Special Features Section above for information on the next gale force gap wind event over the Gulf of Tehuantepec. Another set of long period NW swell is propagating across the NW forecast waters. This swell event is forecast to reach the offshore waters of Baja California Norte by early on Mon, and the remainder of the Baja California Peninsula offshore waters by early on Tue. Marine guidance indicates that seas will build to 12 to 16 ft N of Punta Eugenia on Tue. By that time, fresh to strong NW winds are also forecast to affect the offshore waters N of 26N. These winds will increase to strong to near gale-force by Tue evening before diminishing early Wed. Gulf of California: Winds are light and variable across the area with the typical climatological trough meandering along the west coast of mainland Mexico. Overall, little changes are expected with these conditions through Mon night. Deepening low pressure will move across the southwestern United States on Tue as high pressure intensifies west of Baja California. With this scenario to take place, expect for the pressure gradient to increase over northern Baja California and the northern Gulf of California on Tue leading to near gale force winds across the northern Gulf of California, with seas to 8 or 9 ft by Tue night. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Please see the Special Features Section for more on the gale force gap wind event over the Gulf of Papagayo. Strong north winds will continue over the Gulf of Panama through Sun night, with seas building to 8 ft by early Sun. Elsewhere, gentle to moderate winds will prevail, with seas in the 4 to 7 ft range. REMAINDER OF THE AREA... The pressure gradient between high pressure of 1025 mb centered near 34N130W and lower pressure present near the ITCZ is producing fresh to strong northeast trades from 08N to 20N W of 137W along with seas ranging from 8 to 11 ft based on altimeter data. This area of trades and associated seas will expand north and east through early next week as the high pressure located N of area strengthen some. Yet a new set of NW swell will propagate through the northern and central waters beginning on Sun and through the middle part of the forecast area next week as high pressure strengthens to the north. Seas induced by this new set of swell are expected to be in the range of about 9 to 11 ft. $$ GR