000 AXPZ20 KNHC 250227 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0227 UTC Sat May 25 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 0200 UTC. ...SPECIAL FEATURES... ...Gulf of California Gale Warning... A cold front will approach Baja California Norte Sat and Sat night, and SW gap winds will strengthen ahead of the front across the northern Gulf of California. Strong winds will prevail Sat night through Sun night north of 29.5N with a brief period of gale force winds expected late Sat night into Sun morning. Winds will shift by early Mon, becoming NW to N as the cold front crosses the northern Gulf and weakens. Then, wind speeds over the Gulf will diminish through mid week. ...Excessive Rainfall Over Central America... A large cyclonic gyre that is typical for this time of the year, called a Central American Gyre, will continue bringing abundant moisture and heavy rainfall across portions of Central America during the next few days. Life-threatening flash flooding and mudslides will be possible in areas of mountainous terrain. Please refer to your local meteorological service for more details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from the coast of Panama near 08N78W to 1008 mb low pressure near 11.5N87W to 07N95W to 09N110W to 07N119W. The ITCZ continues from 07N119W to 08N127W to beyond 07N140W. Numerous moderate and scattered strong convection is noted within 240 nm NW quadrant of low center. Scattered moderate convection is occurring within 180 nm south of the trough between 102W and 110W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A weakening high pressure ridge over the Baja California offshore waters has relaxed the offshore pressure gradient, and winds have diminished to gentle to moderate NW breezes. Residual NW swell has continued decaying this evening, and max wave heights were analyzed to 8 ft south of Cabo San Lazaro at 00Z based on recent altimeter data. Fresh winds are expected to develop off the southern tip of Baja California Sur Sat night into early next week as the ridge builds southeastward once again. Expect seas off Baja California to build up to 8-9 ft Tue through Wed as SW swell mixes with locally generated NW wind waves. Smoke and haze from ongoing fires over southern Mexico may briefly reduce visibilities over the nearshore waters from near Las Tres Marias southward to the Gulf of Tehuantepec. Gulf of Tehuantepec: Fresh to strong northerly winds will pulse across the Gulf of Tehuantepec region late tonight and again on Sat night with the assistance of the nocturnal drainage flow. Seas will build to 8-9 ft early Sun morning with the slightly stronger gap winds. Fresh winds early on Mon will diminish to gentle speeds through mid week. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Please read the Special Features section for more information about the Central American Gyre, which will bring heavy rain to parts of Central America and the adjacent offshore waters. As the monsoon trough lifts northward in association with the Central American Gyre, southerly monsoon flow will prevail over the forecast waters and likely strengthen early next week. Seas 8 ft or less this weekend will build to 8-12 ft by mid week as SW swell mixes with locally generated wind waves from strengthening monsoon flow. Some gradual tropical development of a low pressure trough extending from Nicaragua westward to the far eastern Pacific is possible over the next few days if the disturbance remains offshore. REMAINDER OF THE AREA... Residual NW swell lingers over the northern forecast waters with 8-9 ft seas roughly north of 27N between 120W and 132W based on 00Z altimeter data. Wave heights will fall below 8 ft on Sat as the remaining swell over the region decays. Earlier scatterometer data showed fresh NE trade winds between the ITCZ and a high pressure ridge extending southeast across the northern waters. These trades will gradually diminish and seas will subside this weekend as high pressure weakens north of the area. SW swell across the southern waters is producing seas to 8 ft over portions of the forecast waters south of the Equator. Another SW swell event will enter the southern waters on Sun and propagate northward through mid week. This will result in a large area of seas 8 ft or greater south of 11N between 90W and 125W by Tue. $$ Reinhart