000 AXPZ20 KNHC 150957 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Wed May 15 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 0830 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from a 1010 mb low over Colombia near 09.5N73W to 07.5N88W to low pressure near 09N95.5W 1010 mb to 05.5N113W, where it transitions to ITCZ and continues on to 06N124W TO 05N131W to beyond 04N140W. Scattered moderate to strong convection is seen from 04N to 07N E of 80W and from 06N to 1.5N between 83W and 90W. Scattered to locally numerous moderate to strong convection is from 05N to 12.5N between 92W and 101W. Widely scattered moderate isolated strong convection is from 04N to 09N W of 135W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A 1018 mb high near 27N122W extends a weak ridge southeastward to near 18N113W. The pressure gradient between it and troughing over Baja California Peninsula will allow for generally moderate northwest winds to continue across the offshore waters N of 20N, except for locally fresh winds developing along the coast during the afternoon and early evening hours. These conditions are forecast to change little through Thu. A cold front will approach the region from the west Thu afternoon, and move across Baja California Norte Thu evening and night. The pressure gradient ahead of the front will tighten enough to allow for SW gaps winds over the northern Gulf of California to increase to strong beginning on Wed night. These winds will briefly diminish on Thu afternoon before increasing back to strong Thu night. As the front sweeps eastward across the northern Gulf Thu night, strong northwest winds will briefly blast across far north portions of the Gulf before diminishing Fri morning. High pressure building in behind this front will bring fresh to strong northwest winds across the offshore waters of the Baja California Peninsula on Fri and Fri night. Seas will build to 8- 10 ft during this time as NW swell propagates through these waters with the building high pressure. Today is the first day of the Eastern North Pacific Hurricane Season. No tropical cyclone activity is expected for the next several days in the Mexican Offshore Waters. Agricultural fires continue over southern and southeastern Mexico. Areas of smoke linger along the coastal waters of Mexican from Manzanillo to the Gulf of Tehuantepec. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... A weak pressure pattern will maintain generally quiet wind conditions across the region through the forecast period, with generally onshore wind flow expected from the Papagayo region eastward through Fri night. Large cross-equatorial southwest swell affecting the forecast waters for the past few days continues to slowly subside tonight, with seas still in the 6-8 ft range. New long period southwest swell will build waveheights west of Ecuador beginning on Fri. Agricultural fires continue over northern Central America. However, the low-level southerly flow is generally keeping the associated smoke over land and no significant impact on visibility is occurring over the offshore waters at this time. REMAINDER OF THE AREA... A 1018 mb high near 27N122W extends a ridge southeastward to near 18N113W. The pressure gradient south of the ridge is weak providing for mainly moderate to locally fresh northeast tradewinds between the ITCZ and 17N and to the W of 112W. These relatively quiet conditions will continue for the next several days. Overnight altimeter data showed waveheights of 6-8 ft across this tradewind belt, with isolated spots to 9 ft near stronger winds associated with convection. SW swell moving through this region will continue to slowly subside through Fri night. New long-period southwest will build waveheights east of about 125W beginning on Sat. $$ Stripling