000 AXPZ20 KNHC 060335 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 UTC Mon Mar 06 2017 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 0315 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... ITCZ axis extends from 02N100W to 01N110W to 02N119W to 03N125W. No significant convection is noted. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A tight pressure gradient associated with strong high pressure that extends from the southeast U.S. to the Gulf of Mexico and to eastern Mexico is slowly weakening. As a result, northerly winds through the Gulf of Tehuantepec have responded by diminishing to generally strong as of early this afternoon. Seas with these winds are in the 8-10 ft range. Due to the persistence of the recently ended gale force winds over portions of the gulf, swell generated from this event is propagating to the southwest of the gulf and mixing with a southwest swell component within an area marked between 94W and 100W, and from 05N to 11N between 100W and 110W. Seas produced by the mixed swell are in the 8-10 ft range. This swell will gradually decay through Monday evening. A weak pressure pattern over the northern and central waters supports light to gentle northwest winds offshore west of Baja California and gentle to moderate winds for the Mexican waters north of 16N. Seas of 4-6 ft are present in both of these areas. A the eastern portion of a cold front has entered the northeast section of the area. As of 00Z, the cold front is analyzed along a position from 32N118W to 28N125W. The cold front will weaken as it passes across the northeast waters into Monday morning. The front will be accompanied by moderate to fresh north to northeast winds. The leading edge of long period northwest swell associated with strong winds currently behind the front will follow the front and enter the far northern portions of the area north of 29N and west by this evening. This set of northwest swell is forecast to move into the offshore waters of Baja California Norte beginning late Monday afternoon and into Tuesday. By Tuesday, strong northwest winds will develop over the Gulf of California, with seas building to 8 ft. Another Tehuantepec wind event is expected to begin Wednesday as strong high pressure expands to the southwest over the Gulf of Mexico and eastern Mexico in the wake of a cold front expected to move across the Gulf of Mexico. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... High pressure north and east of the region will continue to funnel fresh to strong northeast to east winds into the Gulf of Papagayo and surrounding waters through the forecast period. The areal of these winds has decreased since this morning, but is forecast to expand northward again to near 12N by late tonight. Lesser coverage of the strong pulsing winds is then expected the next few nights as the high northeast of the region weakens. Seas of 8-10 ft within this area will continue through tonight s swell propagates westward and merges with large swell propagating from the Gulf of Tehuantepec. Beginning Monday afternoon and through Wednesday, the lack of swell from Tehuantepec and smaller coverage of strong winds from Papagayo will result in mainly local seas of 8-9 ft from the Papagayo gap winds. By Wednesday night, the areal coverage of strong winds and 8 ft or greater seas will once again increase as another strong high builds north of the area. Over the Gulf of Panama...north to northeast fresh to strong winds through the Gulf will diminish to moderate winds late tonight. Seas to 8 ft with these winds will subside to less than 8 ft late tonight. Elsewhere...light to gentle breezes and seas of 4-6 ft will prevail through early next week. REMAINDER OF THE AREA... A weak pressure pattern is in place as a cold front has recently moved into the north-central waters from 28N125W to near 28N136W. This is resulting in gentle to moderate winds north of 20N over the open east Pacific waters. There remains a sufficient pressure gradient to support an area of fresh northeast trades north of 08N and south of 15N, west of 135W. These trades support 8 ft seas over this area. This area of fresh trades and 8 ft seas will continue the next few days while slowly expanding eastward as high pressure builds north of the area. The aforementioned cold front will be attendant by a new set of northwest swell with induced seas of 8-10 ft forecast to propagate southeastward through the northern waters the next couple of days. By early Monday afternoon, the swell with resultant seas of 8-10 ft will reach the waters north of a line from 30N118W to 26N128W to 24N132W to 24N140W. By Tuesday morning, the swell will reach as far south as 15N and will begin to merge with the other trade wind induced 8 ft seas. By the middle of the week the 8-10 ft seas will be confined from about 05N to 24N, west of 115W, while fresh to strong northeast trades prevail over the region. $$ Aguirre