156 AXPZ20 KNHC 180325 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 UTC Mon Feb 18 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 0200 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...Updated A surface trough extends from northwestern Colombia to 04.5N83W TO 05N94W TO 04N100W. The ITCZ begins from 04N100W TO 00N120W TO 00N130W. Widely scattered clusters of moderate convection are noted within 150 nm N of the ITCZ between 104W and 111W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A strong and persistent ridge extends southeastward across the discussion area, from the NE Pacific through 32N136W to near 10N107W. The tight pressure gradient between the ridge and lower surface pressure over the southwestern United States and Mexico has been supporting strong northwest winds across the offshore waters for over 24 hours, and have finally begun to diminish to around 15-25 kt this evening as the ridge is realigning in advance of an approaching cold front. Seas associated with these winds are in 8-13 ft range in NNW swell, while these marine conditions remain rough and dangerous. A new cold front is sinking SSE across the offshore waters of Southern California this evening and will sweep across far north portions of Baja California tonight through Mon night and act to reinforce this NW wind flow. However, this will also weaken slightly the pressure gradient and lead to winds continuing to slowly diminish to 15-20 kt across most of the waters by Mon night, then become moderate to fresh Tue and Wed. Seas will also gradually subside tonight through Mon as the current large NW swell moves SE of the area. However, reinforcing NNW swell from this next approaching cold front will maintain seas at 7-11 ft Tue through Wed. Gulf of California: Low pressure and its associated cold front will move across the northern part of the Gulf of California tonight, bringing fresh to strong SW to W winds to the northern part of the Gulf of California ahead of the front tonight, and then fresh to strong NW winds behind the front midday Mon through Mon night. Fresh northerly wind flow is then expected throughout most of the Gulf on Tue, diminishing to moderate to locally fresh Tue night through Wed. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gentle northeast winds across the Gulf of Papagayo will increase again to the mainly moderate speeds on Mon, and to stronger speeds of fresh to moderate Mon night into Tue. Light and variable winds are expected elsewhere through Tue, except for the Gulf of Panama where moderate northerly winds are expected. REMAINDER OF THE AREA... A strong 1040 mb high pressure center, well to the north- northeast of the Hawaiian Islands near 42N145W, will remain in this general location through Wed. The associated ridge axis extends southeastward through 32N136W to the tropics near 10N107W, which has forced the ITCZ southward to along the equator. The pressure difference between this ridge and broad low pressure lingering across the Hawaiian Islands area is resulting in a tight pressure gradient across most of the area N of about 08N and W of 110W. Northeast to east winds of 20 to 25 kt are generally west of a line from 30N140W TO 10N128W TO 09N128W TO 08.5N140W, where seas are in the range of 10 to 15 ft. This current overall synoptic pattern will change very little through the next couple of days as low pressure north of the Hawaiian Islands along 25N pulls northward and away from the islands. The area of strong northeast to east winds will persist, but over a gradually smaller section of the western side of the discussion area. The seas there will slowly subside to around the 10 to 12 ft through the next 48 hours as the large swell gradually propagates SE of the area. $$ Stripling