000 AXPZ20 KNHC 152122 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 UTC Tue Sep 15 2020 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 2030 UTC. ...SPECIAL FEATURES... Tropical Storm Karina is centered near 20.7N 122.1W at 15/2100 UTC moving NW at 10 kt. Estimated minimum central pressure is 998 mb. Maximum sustained wind speed is 50 kt with gusts to 60 kt. Numerous moderate and isolated strong convection is noted within 75 nm in the NE semicircle and within 210 nm in the NE semicircle. Karina is forecast to gradually weaken to a tropical depression by Thu afternoon, then is forecast to become a remnant low in two or three days. Please read the latest NHC Public Advisory at https://www.nhc.noaa.gov/text/MIATCPEP1.shtml and Forecast/ Advisory at https://www.nhc.noaa.gov/text/MIATCMEP1.shtml for more details. ...TROPICAL WAVES... A tropical wave axis is along 101W N of 04N, moving W at around 5-10 kt. Associated convection is described below. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 10N86W to 11N101W to 10N106W, then resumes W-SW of Karina from 16N128W to low pressure near 14N135W to beyond 11N140W. Scattered moderate and isolated strong convection is noted from N of the equator to Central America E of 84W, and from 11N to 15N between 107W and 111W. Scattered moderate convection is noted from 08N to 10N between 85W and 87W, from 11N to 12N between 90W and 96W, from 08N to 10N between 98W and 106W, from 13N to 16N between 98W and 106W, from 15N to 17N between 105W and 107W, from 06N to 11N between 107W and 115W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see the Special Features section above for more details on Tropical Storm Karina. South to southwest swell from Karina will continue to spread northward across the offshore waters of Baja California through early Wed. Outside of Karina, light and variable winds prevail W of 110W, with gentle to moderate northwest to north winds elsewhere, except gentle to moderate southerly flow in the Gulf of California. Seas are 4-7 ft outside of the influence of Karina, except 3 ft or less in the central and northern Gulf of California. Moderate northerly winds will build across the offshore N of 20N or so later this afternoon and evening in the wake of Karina, with light to gentle winds elsewhere through the week. By Sat, a weak trough or low may develop offshore of southern Baja California with light and variable winds southeast of it and moderate to fresh northwest winds northwest of the trough. By Sun, the monsoon trough is forecast to lift northward along the outer offshore waters area allowing for E-SE moderate to fresh winds N of it to the S of Cabo Corrientes. Seas will be mainly 4-7 ft in mixed swell across the waters, except 3 ft or less in the Gulf of California. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, and WITHIN 750 NM OF ECUADOR... Gentle to moderate S to SW winds persist south of the monsoon trough, which currently extends across the offshore waters roughly along 10N-11N, and will lift northward and inland during the next few days. Elsewhere, gentle winds prevail north of the monsoon trough Combined seas are currently in the 4-7 ft range in a mix of wind waves and S to SW swell, except 5 to 8 ft south of the equator. Gentle to moderate monsoonal flow will prevail over the waters generally S of 10N for the next several days. Combined seas may slightly increase in the waters S of the equator through Thu night as S to SW swell moves across the region. REMAINDER OF THE AREA... Please see the Special Features section above for more details on Tropical Storm Karina. Tropical storm conditions and large seas will shift northwestward over the next few days as Karina moves farther away from the offshore waters of Mexico while gradually weakening. A cold front is over the NW waters from 32N133W to beyond 27N140W where it continues as a dissipating stationary front, with moderate SW winds ahead of it as noted by recent scatterometer data. The front will drift a little bit more E-SE progress during the next couple of days before stalling out and dissipating. A weak 1021 mb high pressure is centered near 28N132W. South of the ridge, mainly moderate to locally fresh NE trades prevail across the waters north of the monsoon trough. Combined seas are generally 4-7 ft. Moderate to fresh NE winds are found NW of low pressure near 14N135W to 20N, where seas are locally 8-9 ft. A broad area of fresh to locally strong monsoonal flow prevails south of the monsoon trough between 125W and 135W, with seas generally 7-10 ft in this region. Decaying, long-period mixed southerly swell lingers across the waters E of 130W, with 6-8 ft combined seas south of the equator. New southerly swell will move across the southern waters through tomorrow keeping seas to around 8 ft. $$ Lewitsky