000 AXPZ20 KNHC 260328 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 UTC Sat Nov 26 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 0000 UTC surface analysis and satellite imagery through 0300 UTC. ...SPECIAL FEATURES... Tropical Storm Otto is centered near 9.7N 90.7W at 26/0300 UTC, moving WSW or 255 degrees at 14 kt, and a general motion toward the west-southwest or west is expected during the next day or two. Estimated minimum central pressure is 997 mb. Maximum sustained wind speed is 50 kt with gusts to 60 kt. Weakening is expected during the next 48 hours. The center of Otto is located near the eastern edge of the main convective area due to strong easterly vertical wind shear. Numerous moderate to isolated strong convection is noted from 09N-10.5N between 91W and 92W. Scattered moderate convection is elsewhere from 08N-11N between 90W and 93W. Please see the latest NHC advisory under AWIPS/WMO headers MIATCMAT1/WTNT21 KNHC for more details. Gulf of Tehuantepec Gale Warning: The pressure gradient between high pressure over eastern Mexico and tropical cyclone Otto located SE of the Tehuantepec area is supporting gale force winds in the 30-40 kt range over the Gulf of Tehuantepec. Seas will build to 15-16 ft with this gap wind event by early Saturday morning. Then, winds are forecast to diminish to 30-35 kt by early Sunday morning and below gale force by late Sunday morning. Please see the latest High Seas Forecast product under AWIPS/WMO headers HSFEP2/FZPN03 KNHC for more details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The ITCZ extends from 08N96W to 08N110W to 09N120W to 11N128W, then resumes at 11N135W to beyond 11N140W. A surface trough is embedded within the ITCZ and extends from 14N131W to 09N133W. Scattered moderate to isolated strong convection is noted on either side of the trough axis from 11N to 14N between 131W and 133W. Scattered moderate convection is from 08N to 13N between 126W and 132W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see above for more on the Gulf of Tehuantepec gale force gap wind event. 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 cold front passage. NW swell continue to propagate across the offshore waters of the west coast of the Baja California Peninsula with combined seas of 8-12 ft as depicted by a recent altimeter pass. Additional pulses of NW swell will continue to affect the offshore forecast waters during the upcoming weekend. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Please see the special features section above for details on Tropical Cyclone Otto. Elsewhere, light to moderate northwest to north flow and combined seas of 3 to 5 ft prevail north of 10N, with moderate to locally fresh southwest flow and combined seas of 3 to 5 ft south of 10N. Little change is forecast through the upcoming weekend and into early next week outside of the influence of Otto. REMAINDER OF THE AREA... A cold front has reached the NW forecast waters and now extends from 30N132W to 29N136W to 30N140W. This front will continue to move SE across the north waters followed by fresh to strong northerly winds and additional pulses of NW swell, building seas up to 14 ft across the far NE waters by Saturday evening. The pressure gradient between high pressure in the wake of the front and lower pressure in the vicinity of the ITCZ will continue to support a large area of 20 to 30 kt trades across the west-central waters. Seas over this area are in the 8 to 12 ft range in a mix of northwest swell and northeast wind waves. Little change in these marine conditions are expected through the next 48 hours. $$ GR