000 AXPZ20 KNHC 180959 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Sat May 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 0600 UTC surface analysis and satellite imagery through 0945 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from a 1010 mb low over northwestern Colombia near 10N74W to along northern Panama to the coast of Costa Rica at 10N86W, and continues to 14N95W to 13N100W to a 1010 mb low near 11N105W, then to 09N111W and to 07N119W. The ITCZ extends from 07N119W to 05N125W to 05N130W and to beyond the area at 05N140W. Numerous strong convection is within 60 nm north and 30 nm south of the ITCZ west of 138W. Scattered strong is within 30 nm north of the ITCZ between 136W and 138W. Scattered moderate to isolated strong is seen from 09N to 13N and to the east of 90W. Similar activity is occurring within 90 nm south of the ITCZ between 111W and 115W. Scattered moderate convection is within 120 nm south of the ITCZ between 127W and 131W and within 120 nm north of the iTCZ between 134w and 136W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A recent Ascat pass revealed fresh to strong northwest winds within about 90 nm of the coast of Baja California Norte and similarly within 90 nm offshore sections of the coast of Baja California Sur as high pressure builds into the region in the wake of a recent cold front. A few ship observations from last night reported similar winds. Recent altimeter data has confirmed waveheights in the range of 8-10 ft over these waters. Northwest swell and local wind waves are combining with already present long-period southerly swell propagating through the offshore waters off Baja California Norte. This will continue to bring combined seas of 8-9 ft through late Sat, spreading as far south as Cabo San Lazaro and farther south to near 20N before subsiding slightly tonight, but remain present through early next week. Looking ahead, a second cold front will reach Baja California Norte late on Sun, resulting in a brief period of strong to possibly near gale force northwest winds over the northern Gulf of California Sun night and Mon, with fresh to strong northwest winds over the offshore waters of Baja California Mon and Tue. A large set of long-period southerly swell will continue to propagate through the forecast waters through Mon before mixing with northwest swell beginning on Mon night. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... A weak pressure pattern will maintain gentle to moderate onshore winds across most of the region for the next several days. Large cross-equatorial southwest west of Ecuador will move into the outer offshore waters of Central America late Sun into mid week. Deep atmospheric moisture, within a relatively broad area of low pressure, will remain across just about the entire offshore waters of these areas well into next week along with scattered to numerous showers and thunderstorms, some of which can produce very heavy rain and strong gusty winds. REMAINDER OF THE AREA... A ridge extends from a 1022 mb high centered at 30N128W east- southeastward to near 20N115W. A weak pressure gradient south of the ridge is allowing for generally moderate to fresh trades from 07N to 20N and west of 118W. Waveheights with these winds are in the range of 5-7 ft, with the exception of west of 135W where waveheights peaking to 8 ft are a result of a southeast swell component mixing with a northwest swell component. These waveheights are forecast to decay below 8 ft early in the afternoon. A cold front is forecast to move across the northwest part of the area today, reach from near 32N130W to 27N140W this evening and begin to weaken from near 32N115W to 26N124W by early Sun night. Mainly moderate southwest winds will precede this front, with moderate to fresh northwest to north winds to follow in behind it. This front will usher in yet another round of long-period northwest swell, that will sweep across the far northern waters through early Sun, and across the northeast waters Sun night through early next week. Waveheights resulting from thus swell will peak to about 11 ft north of 28N through Sun night and shifting to the far northeast part of the area Mon. $$ Aguirre