435 AXPZ20 KNHC 211020 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Fri Jun 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 0600 UTC surface analysis and satellite imagery through 0900 UTC. ...TROPICAL WAVES... A tropical wave is crossing Central America, extending along 84W- 85W from Nicaragua and Honduras southward to 05N, moving westward 10-15 kt. Scattered to numerous moderate to strong convection extends from from the Gulf of Honduras southeastward to Panama and coastal Colombia. A tropical wave is along 95W-96W from 05N to 16N, moving westward at 10-15 kt. Scattered to numerous moderate to strong convection is seen from 05.5N TO 13N between 90W AND 102W. A tropical wave is along 108W from 04N to 13N, moving westward near 15 kt. Only scattered showers and isolated thunderstorms are noted near this wave. A tropical wave extends NNE to SSW along 126W-129W from 05N to 17N is moving westward at an estimated 15 kt. Middle level cyclonic rotation can be seen in satellite imagery centered near 13.5N125W, with a weak inverted trough reflected below this at the surface. Scattered moderate isolated strong convection is occuring mainly along and ahead of this wave between 127W and 140W as it interacts with an upper level trough along about 138W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from low pressure centered in northern Colombia near 10N74W west-southwestward to 08.5N0W TO 08N106W TO 06N117W TO 11N121W TO 10N132, where it transitions to ITCZ, continuing on to beyond 09.5N140W. Outside of convection described above with the tropical waves, no significant convection is present. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Overnight scatterometer data indicates that gentle to moderate northwest wind continue across the offshore waters of Baja California, while gente to moderate NW to W winds were observed from Cabo Corrientes to Puerto Angel. Seas were running 4-6 ft in mainly northerly swell. Low pressure over the southwestern U.S. will continue to deepened through this morning, with an associated surface trough extend over the Gulf of California. SW to W gap winds have begun to increase over the northern Gulf of California tonight, and will increase through the morning to produce strong to near gale force winds, with seas building to 5- 8 ft. These winds will then diminish to mainly fresh speeds by early Fri afternoon before increasing again to strong late on Fri night and into early Sat. Scattered to numerous showers and thunderstorms along with gusty winds are possible over the extreme southern part of Mexican offshore waters Saturday as a tropical wave passes just south of the Tehuantepec area. Low pressure may form at the start of next week a few hundred miles southwest of the Tehuantepec and along the outer offshore waters there. This is expected to produce fresh to locally strong easterly winds and building seas to the southeast Mexican offshore waters, and bring additional showers and thunderstorms. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Overnight scatterometer data showed fresh offshore gap winds occurring from the Papagayo region to El Salvador ahead of the approaching tropical wave over Central America. Elsewhere north of 11N, gentle easterly flow prevailed. Active weather associated with this approaching tropical wave, and a strong early season tropical wave across the west central Caribbean are expected through the weekend. Southerly swell from the southern hemisphere will continue propagating northeastward across the regional offshore waters, keeping seas in the 5-6 ft range before seas build to 5-8 ft Sun. REMAINDER OF THE AREA... A 1032 mb high remains quasi-stationary well north of the area near 42N139W, with a ridge extending southwestward to just SW of the Revillagigedo islands. To the south of the high pressure, northeast to east trade winds of around 15 kt prevail. Little change in the position of the high or the speed of the trade winds is expected through the weekend. North of 26N, NE to E winds of 20 kt prevail with seas of 8 to 10 ft in northerly swell are being generated by persistent gale force winds off the coast of California. The focus of this swell will move east and gradually shrink in size this weekend. Farther south, long-period cross-equatorial swell is causing seas of 7-9 feet south of about 08N. This swell will decay some Friday, before new swell arrives this weekend, again increasing seas south of 08N to possibly 8-10 feet. $$ Stripling