000 AXPZ20 KNHC 071626 CCA TWDEP Tropical Weather Discussion...corrected NWS National Hurricane Center Miami FL 1605 UTC Tue Feb 7 2017 corrected to include last paragraph 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 1600 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The ITCZ axis extends from 01N108W to 02N124W. Scattered moderate convection is within 240 nm north of the axis. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Northerly winds through the Gulf of Tehuantepec have diminished to 10-15 kt, with seas down to 3-4 ft. The next Gulf of Tehuantepec gap wind event, with gale conditions possible, is expected late Thursday night as strong high pressure builds southward across the Gulf of Mexico in the wake of a strong cold front. High pressure of 1021 mb centered near 26N122W extends a ridge southeastward to near the Revillagigedo Islands. The pressure gradient between the ridge, and weak troughing over the Gulf of California is supporting gentle to moderate northerly winds off the west coast of the Baja California peninsula. Seas in this area are in the 4-6 ft range. Light to gentle winds and seas 2 ft or less prevail over the Gulf of California, while moderate to locally fresh winds and seas 5-6 ft are off the southwest coast of Mexico, with the strongest of these winds confined about 90 nm of the coast of Mexico between Manzanillo and Cabo Corrientes. The high pressure is forecast to move northeastward to near 31N121W while intensifying only slightly. It is then forecast to lift northeastward to near 32N119W by Wednesday afternoon. As this takes place, the pressure gradient between the associated ridging and the trough over the Gulf of California will tighten, thus allowing for fresh to strong northerly winds to develop off the west coast of the Baja California peninsula tonight, and also over the central part of the Gulf of California Wednesday morning through early morning Thursday. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... The pressure gradient between high pressure centered over the western Atlantic and lower pressures over the southwestern Caribbean Sea and central America in combination with overnight drainage flow has induced fresh to strong northeast winds through the Gulf of Papagayo. These winds will diminish to the fresh range by early this afternoon, then pulse again to the fresh to strong range late tonight and into early Wednesday morning, then pulse again to the fresh to strong range late Wednesday night. Model guidance indicates that a surge of stronger high pressure will build south over the Gulf of Mexico beginning late Thursday night and through Friday with ridging extending southwestward towards southern Mexico. In addition, a high center of about 1023 mb is expected to be situated over or near western Guatemala. The gradient between the high pressure and lower pressures over central America and over the southwestern Caribbean Sea will bring another gap wind event through the Gulf of Papagayo on Friday. This next gap event is forecast to extend farther downstream from the gulf of Papagayo Friday through Saturday. The longer fetch and duration should allow for combined seas to build to around 9 ft. Fresh northerly winds through the Gulf of Panama are forecast to diminish to mostly moderate to fresh this afternoon then increase again to moderate to fresh tonight before diminishing to moderate winds on Wednesday. Otherwise, light and variable winds and 4-6 ft seas will prevail elsewhere. REMAINDER OF THE AREA... A ridge, associated with the 1021 mb center of high pressure west of Baja California continues to dominate the northern waters. Long period NW swell propagating through the northwest portion of the area is producing seas in the range of 8-14 ft range there. This swell train, with a leading edge period of 17 to 18 seconds, will reach the Revillagigedo Islands this morning, and near 100W on Wednesday. A relatively tight pressure gradient between the ridge mentioned above and lower pressures in the vicinity of the ITCZ is supporting a belt of moderate to fresh trades roughly from 05N to 14N W of about 114W as was observed in Ascat data from overnight last night. Latest altimeter showed seas of 8-9 ft within this area of winds. These marine conditions will gradually diminish in coverage through Wednesday. Ascat data from overnight last night revealed southwest winds in the 20-30 kt range across the far northwest portion of the area to the northwest of a line from 32N133W to 27N140W with seas of 10-15 ft there. Seas are in the 8-12 ft range in NW swell elsewhere to the northwest of a line from 32N128W to 26N135W to 25N140W. These marine conditions are the result of a series of a rather complex winter pattern north and northwest of the area that consists of a series of deep low pressure centers and associated cold fronts. One such front is just northwest of the area. This front will slow down as it advances eastward towards 140W through tonight. This will maintain a very tight pressure gradient over that portion of the discussion area into early on Thursday, then slacken through Friday as the low pressure systems track farther away from the area. A stronger cold front associated with one of the aforementioned low pressure systems will move across the northwest waters on Wednesday afternoon, and reach a position from near 32N136W to 25N140W by early on Wednesday evening. At that time, expect fresh to strong winds on either side of the front with seas in the range of 12-16 ft behind the front. The maximum waveheight of these seas is forecast to be in the far northwest corner of the area on Wednesday, then subside some on Thursday as the culprit swell train propagates east to southeast and gradually loses energy. Strong southwest winds aloft due to a very pronounced upper jet stream branch rounding the base of a large upper trough centered well to the northwest of the region are advecting ample mid and upper level moisture in the form of broken to overcast clouds east-northeastward across the far northwest section of the area. Scattered showers and isolated thunderstorms are possible with these clouds northwest of a line from 32N125W to 27N135W to 25N140W. $$ Aguirre