000 AXPZ20 KNHC 221605 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Sat Jun 22 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 1545 UTC. ...TROPICAL WAVES... A rather vigorous tropical wave has its axis extending from near 16N96W to 10N97W to 04N98W, moving westward at 10-15 kt. This wave closely coincides with a mid/upper-level trough. Very deep moisture and atmospheric instability surrounds the environment of this wave. Large bursts of deep convection consisting of the moderate to strong type intensity have quickly developing from the overnight hours into this morning. The convection is observed from 12N to 16N between 95W and 100W. Some of the numerical models suggest that low pressure may form along this wave over the next 24 to 48 hours. A tropical wave has its axis along 104W from 04N to 15N. It is moving westward at 10-15 kt. Scattered moderate convection is within 60 nm either side of the wave from 11N to 13N and from 05N to 08N. A tropical wave has it axis along 119W from 04N to 14N, moving westward near 15 kt. This wave remains embedded within a large area of deep atmospheric moisture located to the south of a mid to upper-level anticyclone centered at 19N118W. Only isolated showers and thunderstorms are noted within 90 nm either side of the wave from 08N to 12N. A tropical wave has its axis extending from 15N138W to 09N139W and to 04N140W. It is moving westward at 15-20 kt. Scattered moderate to strong convection has recently developed within 120 nm east of the wave from 10N to 12N. This wave will exit the discussion area this afternoon. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from a 1010 mb low over northwestern Colombia to the coast at 07N78W and from there to 11N94W to 10N105W to 09N114W and to 08N120W, where overnight scatterometer data indicated that it transitions to the ITCZ to 08N120W to 09N130W and to 08N139W. Numerous moderate to strong convection is seen within 180 nm north of the trough between 90W and 95W, also within 180 nm south of the trough between 93W and 96W and within 150 nm south of the trough between 77W and 79W. Scattered moderate convection within 60 nm south of the ITCZ between 120W and 124W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... The resultant pressure gradient from low pressure over the southwestern United States is generating southwest gap winds near gale force over the northern Gulf of California. The gradient will relax by early this afternoon allowing for these winds to quickly diminish to gentle speeds. Waveheights over the northern Gulf will generally range between 5-7 ft. Seas off the west coast of Baja California Norte will range between 6 and 8 ft. The vigorous tropical wave located southwest of the Gulf of Tehuantepec region may spawn low pressure as described above under Special Features as models suggest. According to the latest NHC Tropical Weather Outlook, this low is then expected to gradually develop thereafter, and it may possibly intensify to a tropical depression while it tracks west-northwestward away from the coast of Mexico through the middle portion of the upcoming week. This future scenario would imply increasing winds and seas along with widespread shower and thunderstorm activity to impact the waters mainly between from south of Acapulco to south of Cabo Corrientes. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gentle to moderate winds will continue for most areas, although pulses of fresh easterly gap winds will impact the Papagayo region through Tue, then winds could become strong Tue night. Seas are being dominated by long period S to SW swell from the southern hemisphere. Recent altimeter satellite passes indicated seas of 5-7 feet adjacent to Central America, with seas of 6 to 8 feet noted along the coasts of Colombia and Ecuador. The swell will maintain seas in these areas for at least the next several days. A rather vigorous tropical wave located to the southwest of the Tehuantepec region as described above has helped initiate widespread clusters of moderate to strong convection across the offshore waters mainly between 90W and 100W. This activity will most likely be attended by strong gusty winds and locally higher seas through at least Sun. REMAINDER OF THE AREA... A 1033 mb high remains quasi-stationary well north of the area near 42N140W, with a ridge extending SE from the high to the Revillagigedo Islands. To the south of the high, the pressure gradient between the ridge and lower pressure in the tropics is allowing for northeast to east trades of 10-15 kt. Little change in the position of the high or the speed of trades is expected into early next week. A tight pressure gradient directly to the south of the high is supporting fresh northeast to east winds north of the ITCZ and west of about 125W, along with waveheights in the range of 6-9 ft in northerly swell. Much of the swell is being generated by persistent gale force winds off the coast of California. Wave model guidance indicates that the swell will slowly decay through early next week. Farther south, long-period cross-equatorial swell is resulting in waveheights up to 8 and 9 ft to the south of the Equator. The leading edge of this set of swell will reach northward to near 09N from 100W to 116W on Sun before it begins to subside beginning on Sun evening. Waveheights to 10 ft are possible along and just to the south of 03.4S between 115W and 120W on Sun. $$ Aguirre