000 AXPZ20 KNHC 231611 CCA TWDEP Tropical Weather Discussion...Corrected NWS National Hurricane Center Miami FL 1605 UTC Sun Jun 23 2019 Corrected Special Features section 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. ...SPECIAL FEATURES... A tropical wave situated to the southwest of Mexico has its axis extending from 16N101W to 10N102W and to near 05N102.5W. It is moving westward at a 24 hour estimated speed of around 10 kt. Latest satellite imagery shows large clusters of numerous moderate to strong type convection east of the wave axis from 10N to 15N between 96W and 100W. This wave is embedded within a very moist environment as observed in satellite imagery and in the TPW (Total Precipitable Water) loop animation. This moist environment is found to the southeast and south of a mid/upper- level anticyclone near 20N110W. Earlier scatterometer satellite data showed generally light winds on the northern periphery of the tropical wave, outside of showers and thunderstorms. Global model output continues to suggest that low pressure area will from from this tropical wave by early on Sun. It may possibly intensify into a tropical cyclone over the next few days as it slowly tracks in a general west-northwestward motion. This system will bring increasing winds and building seas to the offshore waters between Puerto Angel and Cabo Corrientes through the forecast period. Strong to near gale force gap winds are possible over the Gulf of Tehuantepec Wed night through Thu night in the wake of the developing low. This wave has a medium chance of becoming a tropical cyclone during the next 48 hours. Please refer to the latest NHC Tropical Weather Outlook under AWIPS/WMO headers MIATWOAT/ABNT20 KNHC or at website https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml for further details. ...TROPICAL WAVES... A weak tropical wave with axis along 85W north of 06N to inland northern Costa Rica and the central part of Nicaragua is moving westward at 10-15 kt. Numerous moderate to strong convection, enhanced by the monsoon trough, is within 60 nm either side of the wave from 06N to 09N. This wave may eventually encroach on a low pressure area possibly forming off southern Mexico in the next day or two. A tropical wave has its axis along 112W from 03N to 14N. It is moving westward at 15-20 kt. Scattered moderate isolated strong convection is noted within 120 nm w of the wave from 10N to 13N. Similar activity is within 120 nm east of the wave from 07N to 09N. This wave continues to move through a very moist and unstable atmospheric environment. Convection is likely to increase along and near this wave over the 24 hours. A tropical wave has it axis along 122W from 04N to 15N, moving westward at 10-15 kt. Recent scatterometer satellite data shows no clear surface impact from this wave, only isolated showers and thunderstorms are near this wave. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from low pressure of 1009 mb located over far northwest Colombia near 09N76W to 09N90W to 12N103W and to 11N120W. Overnight scatterometer data indicated that the ITCZ begins at 10N125W to beyond the area at 08N140W. Numerous moderate to strong convection is within 180 nm south of the trough between 76W and 88W and within 90 nm north of the trough between 88W and 93W. Scattered moderate to strong convection is within 180 south of the trough between 114W and 117W and within 120 nm north of the trough between 96W and 100W. Scattered moderate to isolated strong convection is occurring within 180 nm south of the trough between 89W and 98W. Scattered moderate convection is within 180 nm south of the trough between 103W and 111W, and within 120 nm south of the ITCZ between 128W and 131W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... See Special Features section above for details regarding a tropical wave that is forecast to generate low pressure, with potential to develop into a tropical cyclone during the next few days. Overnight scatterometer data highlighted light to gentle winds off southern Mexico. Latest altimeter data detected waveheights in the range of 4-6 ft, likely with a component of SW swell. But the relatively tranquil conditions may not persist. Developing deep convection over the waters south of Puerto Angel in the vicinity of a tropical wave, as described above under Special Features, may be suggesting that low pressure may develop in the short term within the area along the monsoon trough. This will be the main weather feature to monitor for the waters adjacent to southern Mexico through mid week as the low pressure develops and consolidates. If this scenario plays out, expect higher winds, building seas and increasing coverage of showers and thunderstorms for the offshore waters from Punta Angel to Cabo Corrientes through mid week. Beyond 48 hours, global models indicate strong to near gale force gap winds into the Gulf of Tehuantepec Wed night through Thu night in the wake of the developing low pressure. Farther north, a modest pressure gradient will support gentle to moderate winds and slight to moderate seas across the area. The developing low pressure may move near the Revillagigedo Islands later in the week. 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 to strong northeast to east gap winds will impact the Papagayo region through Thu night. Seas are being dominated by long period south to southwest swell from the southern hemisphere. Recent altimeter satellite passes indicated seas of 5-7 ft adjacent to Central America, with seas of 6-8 ft noted along the coasts of Colombia and Ecuador. The swell will maintain seas in these areas for at least the next several days. The southern portion of the tropical wave along 85W is triggering numerous moderate to strong convection over the offshore waters E of about 88W. This activity will most likely be attended by strong gusty winds and locally higher seas through at least tonight or longer. REMAINDER OF THE AREA... A 1030 mb high pressure center is ell north of the area near 40N136W. A ridge extends southeastward from this high to the Revillagigedo Islands. To the south of the high, the pressure gradient between the ridge and lower pressure in the tropics is supporting moderate northeast to east trades to the north of the ITCZ and west of about 120W. Little change in the position of the high or the speed of trades is expected for the next several days. Waveheights in this area will generally run between 5-7 ft. Farther south, long-period cross-equatorial swell is maintaining waveheights of 8 to 9 ft to the south of 09N between 100W and 120W. This area of seas will begin to subside this evening. Waveheights to 10 ft are possible along and just to the south of 03.4S between 115W and 120W today. $$ Aguirre