000 AXPZ20 KNHC 241602 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1502 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 1200 UTC surface analysis and satellite imagery through 1500 UTC. ...SPECIAL FEATURES... Hurricane Otto in the SW Caribbean Sea near 11.0N 83.4W at 24/1500 UTC or about 65 nm NNW of Limon, Costa Rica and about 65 nm SSE of Bluefields, Nicaragua moving west at 8 kt. Maximum sustained wind speed is 75 kt with gusts to 90 kt. Estimated minimum central pressure is 975 mb. Associated deep convection is spreading inland from the SW Caribbean Sea over Costa Rica, Nicaragua and Honduras. Very heavy rainfall is increasing the likelihood of flash flooding and mudslides. Otto will make landfall over extreme southeastern Nicaragua around midday today. The official forecast then tracks Otto across Central America near the border of Costa Rica and Nicaragua through tonight. Otto will emerge into the Pacific Ocean near the Gulf of Papagayo around dawn on Friday. The forecast track of Otto carries it S of the Gulf of Tehuantepec as a tropical storm on Saturday night. Please see the latest NHC advisory under AWIPS/WMO headers MIATCMAT1/WTNT21 KNHC for more details. Gulf of Tehuantepec Gale Warning: A high pressure ridge extending southward across eastern Mexico is tightening the pressure gradient over southeast Mexico. Gap wind flow over the Gulf of Tehuantepec reached gale force in the most recent satellite- derived wind data. Gale force winds are forecast to persist until Sunday morning, with winds up to 40 kt expected Friday night into early Saturday. Seas will eventually build to 16 ft by Friday night. A very weak pressure pattern will then prevail Sunday through early next week with more tranquil marine conditions expected for that time period. However...swell from Otto could maintain combined seas S of the Gulf of Tehuantepec above 8 ft on Sunday and Monday. 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 axis extends from 09N84W to 05N98W. The intertropical convergence zone axis continues from 05N98W to 08N104W to 07N114W to 09N121W to 11N133W. The ITCZ resumes from 11N136W to 10N140W. No significant convection is present. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... High pressure across the U.S. Rocky Mountain region combined with elongated inverted surface troughing over NW Mexico is generating fresh to strong NW winds over the northern and central Gulf of California. Winds will top out at 30 kt today with seas building to around 8 ft. Some of these winds will manage to spill out to the W of Baja California Norte through passages. The gradient will then relax tonight. A cold front will move across the area this weekend. Winds will increase to strong speeds 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, finally diminishing on Monday afternoon. The tight pressure gradient offshore of Point Conception, California is beginning to lessen. This will allow the fresh to strong northerly flow in this area to abate. Associated northerly swell are propagating into the area offshore of the W coast of the Baja California Peninsula. A new set of NW swell will also arrive by tonight building combined seas to 8 to 11 ft. Seas will decay Friday through Saturday, then reinforcing northwest swell will arrive for the remainder of the weekend through early next week. A strong cold front will move toward Baja California Norte Sunday night and early Monday. Fresh to strong NW winds behind the front will cause seas to build to 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 NW to N flow and combined seas of 3 to 5 ft prevail N of the monsoon trough. Moderate to locally fresh SW winds and combined seas of 3 to 5 ft are noted S of the monsoon trough. Little change is forecast through 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 extends across the waters north of the ITCZ. A surface trough is embedded in the ITCZ from 09N135W to 16N133W, with associated scattered moderate convection from 08N to 14N between 123W and 135W. The pressure gradient between the trough and ridge continues to support fresh to strong trades across the waters W of 120W from 10N to 20N. These winds are combining with NW swell to produce seas of 8 to 11 ft. High pressure building to the N of the forecast area will cause this area of winds and seas to expand on Saturday and Sunday. $$ cam