000 AXPZ20 KNHC 242156 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2126 UTC Thu Nov 24 2016 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 2100 UTC. ...SPECIAL FEATURES... Hurricane Otto is moving farther inland over southern Nicaragua. At 24/2100 UTC...Otto is centered near 11.0N 84.3W or about 50 NM E of San Carlos, Nicaragua moving west or 270 degrees at 10 kt. Estimated minimum central pressure is 979 mb. Maximum sustained wind speed is 85 kt with gusts to 105 kt. On the forecast track, the center of Otto will continue to move across southern Nicaragua and northern Costa Rica through this evening, and emerge off of the Pacific coast of southern Nicaragua or northern Costa Rica by early Friday. Otto is expected to become a tropical storm by tonight. Additional weakening is anticipated after Otto moves over the Pacific Ocean. Please see the latest NHC advisory under AWIPS/WMO headers MIATCMAT1/WTNT21 KNHC for more details. Gulf of Tehuantepec Gale Warning: High pressure ridging is surging southward across eastern Mexico, tightening the pressure gradient across southeast Mexico. Northerly flow in the Gulf of Tehuantepec has increased to gale force as measured by the most recent scatterometer passes. Gale force winds are forecast to persist through Saturday night, with winds up to 40 kt expected Friday night through at least Saturday night. Seas will eventually build to 16 ft with this gap wind event. Please see the latest High Seas Forecast product under AWIPS/WMO headers HSFEP2/FZPN03 KNHC for more details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 09N84W to 05N98W. The Intertropical Convergence Zone axis extends from 05N98W to 08N110W to 09N120W to 11N134W, then resumes W of a surface trough from 11N136W to 10N140W. Scattered moderate convection is from 10N to 15N between 124W and 129W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... High pressure across the U.S. Rocky Mountain region combined with elongated inverted surface troughing over northwest Mexico is supporting fresh to strong northerly winds over the northern and central Gulf of California. Seas are expected to build to 8-9 ft N of 29N later this afternoon. Some of these winds will surge through passages across northern Baja California. A cold front will move across the area this weekend. Winds will increase to near gale force in the Gulf of California north of 29.5N Saturday night through early Sunday both ahead of and behind a pre-frontal trough, with winds diminishing by Sunday afternoon. Winds will increase again Sunday night into early Monday with the actual frontal passage, diminishing Monday afternoon. A tight pressure gradient is also present offshore of Point Conception, California, with fresh to strong northerly flow present. These winds are producing fresh northerly swell which is propagating into the area offshore of the west coast of the Baja California Peninsula. A set of northwest swell will also arrive by tonight with building seas of 8 to 11 ft. Seas will then decay on Saturday, with reinforcing northwest swell arriving for the remainder of the weekend into early next week. A strong cold front will move toward Baja California Norte Sunday night into early Monday bringing fresh to strong northwest winds behind it and large seas of 10 to 15 ft. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... See the special features section above for details on approaching Tropical Cyclone Otto. Elsewhere, light to moderate northwest to north flow and combined seas of 3 to 5 ft prevail north of the monsoon trough, with moderate to locally fresh southwest flow and combined seas of 3 to 5 ft south of the monsoon trough. Little change is forecast through the upcoming weekend and into early next week outside of the influence of Otto, except for seas building slightly to 4 to 6 ft by early Saturday. REMAINDER OF THE AREA... A strong ridge dominates the N waters. A surface trough is embedded in the ITCZ extending from FROM 10N135W to 16N134W. Scattered moderate convection is noted within 120 NM E of the trough from 11N to 15N. The pressure gradient between the trough and the ridge continues to support 20 to 30 kt trades across the west-central waters. These winds combined with primarily northwest swell are producing seas of 8 to 12 ft. Little change in this pattern and marine conditions is expected through the upcoming weekend. $$ GR