000 AXPZ20 KNHC 092200 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 UTC Tue Jul 09 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 1800 UTC surface analysis and satellite imagery through 2115 UTC. ...TROPICAL WAVES... A tropical wave with axis along 94W from 03N to 15N is moving westward at 10-15 kt. A 1011 mb low is located along the wave near 09N94W. The wave is embedded within a very moist atmospheric environment as depicted by the total and low-level precipitable water satellite imagery. This wave has a good track history as it moved across the Caribbean Sea and into the eastern Pacific waters. Middle to upper level diffluent flow support isolated moderate convection to the E of the wave axis from 10N to 15N between 88W and 94W. Scattered moderate convection and tstms are to the W of the wave axis from 06N to 14N between 96W and 103W. The 1011 mb low accompanying this wave is forecast by the NWP models to acquire some gradual development as it tracks in a general west-northwest motion Thu through late Fri before it weakens to a trough afterwards. A tropical wave with axis along 117W from 03N to 12N is moving westward around 10 kt. This wave is moving through an environment of decreasing atmospheric moisture. Scattered showers and isolated thunderstorms are from 04N to 10N between 110W and 119W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from the coast of Costa Rica near 08N83W to low pressure near 09N94W 1013 mb to 07N105W, where it transitions to the ITCZ, which continues to 07N110W to just east of the wave tropical that is along 117W at 07N115W. The ITCZ resumes just west of the same wave at 07N120W and continues to 08N130W and to beyond 09N140W. Scattered moderate isolated strong convection is N of 05N between 78W and 83W. Scattered moderate convection is from 03N to 08N between 84W and 94W, and from 06N to 13N between 129W and 137W. Numerous moderate to strong convection is from 06N to 11N W of 137W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... The remnants of former tropical cyclone Cosme continue to allow for a generally relaxed pressure gradient west of the Baja California Peninsula. This is allowing for the continuation of light to gentle northwest to north winds over these waters with a few small pockets of moderate winds S of 24N between 109W and 113W. The remnants of Cosme will open into an open wave on Wed and dissipate afterwards, allowing for the ridge to rebuild eastward. This will result in a slightly stronger pressure gradient that will support moderate to fresh northerly flow off Baja through early Sat. Light to gentle winds will dominate the offshore waters the remainder weekend. Gulf of California: Light to gentle variable winds will dominate the entire gulf through early Sat. Generally lower pressure along the Baja California Peninsula will deepen afterwards, resulting in moderate southeasterlies along the central and southern portions of the gulf through Sun morning. Gulf of Tehuantepec: Mainly moderate easterlies will dominate the Tehuantepec offshore waters through Wed night as a tropical wave moves through the area. Generally light and variable winds will continue afterwards through the remainder of the week and weekend with waveheights in the range of 4-6 ft. Scattered to numerous showers and thunderstorms are moving across the eastern section of the corresponding offshore waters. This activity will continue to spread westward across these waters through Wed night. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Scattered showers and thunderstorms across the offshore waters will briefly cease Wed evening, however a tropical wave approaching from the Caribbean will bring back showers to the region Thu. Long-period south to southwest swell will begin to reach the waters south of the Galapagos Islands and west of Ecuador on Thu. The swell will continue to propagate NNE to the Colombia and Central America offshore waters on Fri and Sat, with seas building to 10 ft between Ecuador and the Galapagos Islands. REMAINDER OF THE AREA... The weakening post-tropical remnant low of Cosme is centered near 22N121W with a pressure of 1012 mb. There is no convection associated with the low at this time, however latest scatterometer data show 15-20 kt winds within 210 nm of the low center in the northwest quadrant. Current seas associated with this low are 6 ft. The low will continue on a WNW motion through Wed as it gradually opens up to a trough. Waveheights around the low will continue to subside through Wed night. The pressure gradient across the high seas domain remains weak. A persistent broad ridge centered just north of the area will shift slightly southeastward through the end of the week, and while a tropical wave continues on westward west of 120W. The resultant pressure gradient is expected to increase the northeast to east trades to mainly the moderate to fresh range across the trade wind belt. Waveheights may peak to 8 ft Thu through Fri west of about 120W from the combination of the increasing trades and prevailing predominate southwest long-period swell propagating through these waters. $$ Ramos