National Hurricane Center's Tropical Weather Discussion

Eastern Pacific Ocean

748 AXPZ20 KNHC 211535 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1459 UTC Tue May 21 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 1200 UTC surface analysis and satellite imagery through 1500 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from the coast of Costa Rica near 10N85W to 07N120W. The ITCZ begins at that point and ends near 06N135W. Scattered moderate and isolated strong convection is present north of 06N and east of 90W as well as within 60 nm of the ITCZ between 133W and 137W. Numerous moderate and scattered strong convection is observed from 04N-09N between 98W-108W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... The pressure gradient between a ridge west of Baja California and lower pressure across the SW United States and NW Mexico supports moderate to fresh NW winds in the offshore waters, except for strong NW winds between Punta Eugenia and Cabo San Lazaro. These conditions will prevail through Thu night with strong winds and peak seas reaching to 12 ft NW of Punta Eugenia. Winds and seas will gradually subside Thu and Fri. Gulf of California: The same pressure gradient between a ridge west of Baja California and lower pressure across the SW United States and NW Mexico supports strong W to NW winds in the northern Gulf of California. These winds will diminish Thu and Fri. Seas will build to 8 ft Wed night and subside Thu morning. Ahead of a cold front on Sat, SW winds will be enhanced in the northern Gulf of California. Smoke and haze from fires across southern Mexico could reduce visibilities over the southern Mexican offshore zones for at least the next couple of days. No tropical cyclone activity is expected in the Mexican offshore zones over the next few days. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... A weak pressure gradient across the region will cause quiescent wind conditions for the next several days. Mixed SW and S swell are contributing toward combined seas of up to 8 ft in all of the Central America, Colombian, and Ecuadorian coastal zones. An altimeter pass around 1200 UTC this morning indicated peak seas of 8-9 ft in the Gulf of Papagayo, due to these SW-SW swell along with some wind waves induced by moderate breeze E winds. These swell will subside some Wed through Sun. Abundant atmospheric moisture, along with conducive large scale lift, will contribute to the development of scattered to numerous showers and thunderstorms for the next few days over the Central American offshore zones. Tropical cyclone formation is unlikely during the next couple of days, but is possible by the weekend. REMAINDER OF THE AREA... A ridge extends east-southeastward from a 1028 mb high at 37N141W down to the Revillagigedo Islands. The moderate pressure gradient south of the ridge is supporting up to fresh breeze NE tradewinds. West of 130N between about 10-15N, the fresh breeze NE winds are combining with some N and SW swell to cause peak seas of 8-9 ft as observed by a couple of altimeter passes around 0600 UTC this morning. A NW swell of about 12 ft will be arriving along the 30N Wed morning and will reach around 18N Fri morning before gradually diminishing. Additionally, a new round of SW swell will reach the southern boundary at 03.4S on Wed and product and cause peak seas of about 8 to 9 ft south of about 05N before diminishing on Sat. Tropical cyclone formation is unlikely during the next couple of days, but is possible by the weekend. $$ Landsea