000 AXPZ20 KNHC 100229 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 201 UTC Fri May 10 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 0230 UTC. ...SPECIAL FEATURES... Gulf of California Gale Warning: The pressure gradient between deepening low pressure over the SW United States and an offshore high pressure ridge is enhancing gap winds over the northern Gulf of California. These should shortly be reaching SW gale conditions, though no observations have been available in the area during the last few hours. Strong winds will persist over the northern Gulf Fri and Fri night north of 29.5N, then gradually diminish as the ridge west of Baja California breaks down. Otherwise, light to moderate winds will prevail over the central and southern Gulf through early next week. Please read the latest High Seas Forecast issued by the National Hurricane Center under AWIPS/WMO headers FZPN03 KNHC/HSFEP2 or at website https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml for further details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A trough extends from the Costa Rica coast near 11N86W to a 1007 mb low pres near 08N91W, and then to 07N108W. The ITCZ continues from 07N108W to 06N135W, where it is broken by a trough along 138W. Widely scattered moderate convection is present within 120 nm of the trough from 88W to 98W. Scattered moderate and isolated strong convection is located within 120 nm of the ITCZ west of 105W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... See above in Special Features for Gale Warning and forecast discussion for Gulf of California. A broad high pressure ridge extends from 30N140W to the Revillagigedo Islands. A weak pressure gradient to the east of the ridge is supporting generally moderate breeze or weaker NW to N winds. While agricultural fires persist over southern Mexico, low level winds are transporting the smoke northward toward the Gulf of Mexico. Therefore, no visibility impacts are expected over the Pacific waters at this time. Low pressure developing off the coast of southern California will pull a weak surface trough across the northern waters on Fri. This will displace the ridge farther south into the weekend with fresh NW to N winds developing near the entrance to the Gulf of California and over the waters west of Cabo Corrientes. The surface ridge will become re-established along the northern boundary by Mon. Long-period SW swell will impact the open waters through early next week. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Agricultural fires continue over Central America, but the low level flow is transporting the smoke northward over the Gulf of Mexico. Therefore, no visibility impacts are expected over the Pacific waters at this time. Widely scattered showers and thunderstorms are active south of 10N in the vicinity of the seasonal low pressure trough. A significant S to SW Southern Hemisphere swell event is reaching the Ecuador offshore waters tonight and will spread northward across the waters off Central America through Sat night. Another round of SW swell will move across the region Sun and slowly diminish through Tue. No significant gap wind events are expected over the Gulf of Papagayo and Gulf of Panama through early next week. REMAINDER OF THE AREA... A broad high pressure ridge extends from 30N140W to the Revillagigedo Islands. A weak pressure gradient to the south of the ridge is supporting generally moderate breeze or weaker NE tradewinds. Little change is expected during the next several days. Large, long period S to SW swell over the far southern waters will steadily propagate northward through this weekend. A recent altimeter pass over the southern waters near 100W confirmed 10 ft seas about to reach the Equator. Seas will build to 12 ft south of the Equator between 100W and 110W later tonight with 8 ft seas spreading as far north as 09N by Fri night. By Sun, the southerly swell will cover the forecast waters south of 20N and east of 120W with combined seas of 8 ft or greater south of 10N. Seas will subside beginning Mon as the long period swell gradually decays in this region. $$ Landsea