000 AXPZ20 KNHC 131019 AAA TWDEP Tropical Weather Discussion...Updated NWS National Hurricane Center Miami FL 1019 UTC Wed Mar 13 2019 Updated ITCZ/Monsoon Trough section for convection 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 0600 UTC surface analysis and satellite imagery through 1000 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...Updated A trough extends from Costa Rica near 07N81W to 05N90W. The intertropical convergence zone (ITCZ)continues from 05N90W to 04N100W to 03N112W to 04N125W and to beyond 04N140W. Scattered moderate convection is seen within 240 nm north of the ITCZ west of 136W, and south of the ITCZ within 30 nm of a line from 01N133W to 04N134W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A cold front is dissipating from near Mazatlan to over the far eastern Pacific waters southwest of Los Cabos near 17N114W. A tight pressure gradient between the front and high pressure behind it is bringing strong northwest winds off the coast of Baja California Norte. A tight pressure gradient between very deep low pressure over the western United States and the high pressure that is building east-southeast over the northeast part of the area is allowing for strong to near gale force southwest to west winds to develop in the far northern Gulf of California near 30N. Large, long-period northwest swell is following in behind the cold front as was revealed by recent altimeter passes. This data indicated wave heights in the range of 11 to 14 ft in the offshore waters north of Punta Eugenia, and 8 to 12 ft farther south to the Revillagigedo Islands. Hazardous surf conditions are possible along the coast of Baja California due to the long period swell. For the forecast, a reinforcing front that is along a position from near 32N119W to 31N124W and to 32N133W will move across the waters off Baja California Norte later this morning, then move south through the region before stalling and dissipating over the southern Gulf of California and Baja California Sur by early Thu. Strong high pressure will build over the Great Basin in the wake of the present deep low pressure system there and support fresh to strong northwest winds across the Gulf of California beginning on Thu evening. The northwest swell currently off the coast of Baja California will continue to propagate southward, reaching near Cabo Corrientes by late Thu. High pressure building over the Great Basin will support at least fresh northwest winds across the Gulf of California Thu. Farther south, gale force north to northeast winds are possible across the Gulf of Tehuantepec beginning early on Sat preceded by near gale force winds late on Fri. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... A modest ridge north of the area will continue to support fresh to strong northeast winds pulsing across the Gulf of Papagayo through late week. Winds will be strongest during the overnight and early morning hours with the assistance of nocturnal drainage flow. Fresh to strong north to northeast winds are over the Gulf of Panama and waters downstream from there to near 05N. These winds will diminish to mainly fresh speeds by early this afternoon, then pulse back up to fresh to strong speeds late tonight before diminishing to moderate speeds by early Thu afternoon. Gentle to moderate winds with mixed swell will persist elsewhere through Sun. REMAINDER OF THE AREA... Strong high pressure ridging is building east-southeastward across the waters in the wake of the previously described dissipating cold front. Per latest available Ascat data and a recent observation from the German research vessel Sonne with call sign "DBBE" at a position of 14N125W, winds throughout are mainly in the moderate to fresh category with wind direction from the northeast to east. The exception is within the area bounded from 08N to 14N and between 127W and 136W, where winds are reaching strong speeds since the pressure gradient there as induced by strong high pressure of 1030 mb north of the area at 38N132W is sufficient enough to sustain these wind speeds. These winds are forecast to diminish to fresh speeds by early this evening as the strong high pressure shifts east-southeast and weakens some. Long-period northwest swell persists over much of the region west of 120W, and various altimeter passes over the past several hours indicate wave heights to 12 ft. The swell will continue to propagate southward and cover much of the region west of about 100W by late Thu. The swell will subside below 12 ft north of 15W, with 8 to 9 ft seas in a mix of northwest swell and shorter period northeast trade wind swell farther south into the tropics. Looking ahead, the swell will diminish below 8 ft almost everywhere through Sun, just as a new round of large, northwest swell moves into the region south of 32N and east of 140W by early Sun ahead of an approaching cold front. This cold front is presently forecast to be preceded by strong to near gale force southerly winds. $$ Aguirre