000 AXPZ20 KNHC 190959 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Sun May 19 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 northwest Colombia near 10N75W to across northern Panama, then to the coast at 09N84W. It continues from there to a 1008 mb low pressure near 11N93W to 11N105W and to 07N119W, where an overnight scatterometer pass indicated that it transitions to the ITCZ and continues to 06N129W and to beyond the area at 05N140W. Scattered strong convection is seen within 150 nm north of the ITCZ between 122W and 126W. Scattered strong convection is within 150 nm north of the ITCZ between 122W and 126W. Scattered moderate to strong convection is within 60 nm south of the ITCZ between 122W and 126W, and within 30 nm of the trough and ITCZ between 118W and 121W. Scattered moderate to isolated strong convection is within 60 nm north of the trough between 113W and 118W. Scattered moderate convection is noted within 60 nm south of the trough between 78W and 81W, and within 60 nm north of the trough between 108W and 113W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... The overnight Ascat pass showed moderate to fresh northwest winds offshore the Baja California coast mainly north of Cabo San Lazaro. Waveheights over these waters are in the range of 6-8 ft due primarily to southerly swell, but also with a component of northwest swell. Gentle to moderate northwest winds are over the offshore waters south of Cabo San Lazaro. Waveheights there are in the 5-7 ft range from southwest swell. Relatively weak high pressure over these waters will weaken slightly today in response to the next cold front to impact the forecast waters. This front will move across the waters off Baja California Norte and over the northern Gulf of California this evening through early Mon while it quickly weakens, eventually dissipating by early Mon afternoon. Before the front dissipates, a tight gradient will develop out ahead it inducing strong west to northwest winds over the far northern Gulf of California this evening and tonight. The gradient will slacken Mon afternoon allowing for these winds to diminish. Wave model guidance suggests that a large set of long-period southerly swell will continue to propagate through the forecast waters through the period, except mixing with northwest swell left behind in the wake of the aforementioned cold front over the waters west of Baja California through Tue night. Looking ahead, another cold front may move across Baja California Norte and the northern Gulf of California by the middle part of the upcoming week followed by much stronger high pressure. Per latest model guidance this new high pressure is expected to usher strong northerly winds and building waveheights across much of the northern waters at that time. 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 swell off Ecuador will move into the outer offshore waters of Central America beginning tonight and into the middle part of the upcoming week. Plenty of atmospheric moisture over this region will help contribute to the development of scattered, to at times, numerous showers and thunderstorms over these waters well into the upcoming week. Some of this activity may be capable of producing very heavy rain and strong gusty winds. REMAINDER OF THE AREA... A cold front extending from near 32N124W to 27N131W and to 26N138W will begin to weaken as it reaches a position from near Baja California Norte to 27N122W and to 24N136W this evening, and dissipate by early Mon afternoon as it pushes southeastward across central Baja California. A set of northwest swell is following in behind the front, with waveheights in the range of 8-11 ft. The swell will propagate as far south as 19N and west of 111W by late Mon. The waveheights will peak to 11 or 12 ft over the far northeast forecast waters before the swell begins to slowly decay late on Mon. As high pressure builds in behind the front, the present moderate to fresh trade winds occurring from 07N to 20N west of 120W will become mainly fresh in speeds while increasing in coverage well into the upcoming week. The combination of the northerly swell, a component of southerly swell and local winds will allow for waveheights within this area of trade winds to build west of 120W through mid week. Increased trade wind convergence will also allow for showers and thunderstorms to increase along the ITCZ from Mon through late Wed. $$ Aguirre