000 AXPZ20 KNHC 250920 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0920 UTC Mon Nov 25 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 axis is near 117W south of 16N, moving west around 10 kt. Scattered moderate isolated strong convection is noted from 13N to 16N between 115W and 120W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 07N77W to 05N90W to 07N99W. The ITCZ extends from 07N99W to 13N114W, then continues from 10N132W to 09N140W. Scattered moderate isolated strong convection is noted within 120 nm NE of a line from 10N131W to 06N126W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Gentle N to NE winds prevail across the Baja California offshore waters per overnight scatterometer data. Elsewhere, moderate to fresh NW winds are noted across the central and southern Gulf of California. Farther south, light and variable winds persist over the southern Mexico offshore zones, except for fresh to strong northerly gap winds over the Gulf of Tehuantepec. A broad upper level low centered roughly along 125W will gradually shift SE and induce surface low pressure development this morning near 20N120W. This system will draw deep layer tropical moisture over Baja California Sur and the southern Gulf of California through mid week, supporting widespread showers and thunderstorms spreading NE across the region. The resulting surface low will likely track NE north of the Revillagigedo Islands and move across Baja California Sur into Sinaloa Wed and Wed night. Expect strong to near gale force winds and rough seas associated with this system as it crosses the offshore waters and the entrance to the Gulf of California. There is increasing model support that gale force winds may occur with this system, although significant differences in the timing and track of the system limit confidence at this time. Elsewhere, a large set of NW swell will move across the northern waters Tue and Tue night. A cold front will cross the Baja California waters Thu into Fri, accompanied by another round of large, long period NW swell. Over the Gulf of Tehuantepec, strong northerly gap winds will diminish this morning as the local pressure gradient weakens. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Partial scatterometer data from earlier tonight revealed light and variable winds across much of the offshore waters off Central America, except for moderate to fresh easterly winds noted across the Gulf of Papagayo. Elsewhere, gentle southerly flow prevails between Ecuador and the Galapagos Islands. Fresh to occasionally strong NE to E winds will pulse across the Gulf of Papagayo region through the week, with seas generally remaining less than 8 ft. Gentle to moderate SW monsoonal flow will persist across the offshore waters of Costa Rica, Panama, Colombia, and Ecuador for the next several days, along with moderate long period SW swell supporting 4-7 ft seas. REMAINDER OF THE AREA... A broad surface trough extends across the waters north of 20N between 123W and 127W, supported by an upper level low centered over the region. Overnight scatterometer data shows an area of fresh to strong winds east of the trough axis. Scattered moderate isolated strong convection is noted in recent satellite imagery from 16N to 20N between 119W and 125W. Elsewhere, a large area of fresh to strong NE trades prevails west of 125W between the ITCZ and high pressure centered north of the region. Altimeter data sampled near the strongest winds revealed 9-12 ft seas across these waters. The broad upper level low is expected to induce surface low pressure development near 20N120W this morning. Expect strong to near gale force winds and building seas with this low, while an elongated surface trough will extend well SW of the low center. The strong pressure gradient west of the low will maintain strong trades with seas building to 10-14 ft west of 125W by tonight. The low will drift E-SE through Tue, then move E-NE toward Baja California Sur through mid week. Looking ahead, a cold front will drop southward into the northern waters Wed night and Thu, followed by another round of large, long period NW swell. Combined seas may build to 16 ft by Thu west of Guadalupe Island. Seas greater than 8 ft will cover most of the region north of 20N by late Thu and persist through Fri. $$ Reinhart