000 AXPZ20 KNHC 260935 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 524 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 0600 UTC surface analysis and satellite imagery through 0900 UTC. ...SPECIAL FEATURES... Tropical Storm Otto is centered near 9.2N 92.5W at 26/0900 UTC, moving W or 260 degrees at 16 kt. Estimated minimum central pressure is 1000 mb. Maximum sustained wind speed is 45 kt with gusts to 55 kt. Convection associated to Otto is sheared to the west of the system center. Numerous moderate and scattered strong convection is noted from 08.5N-11N between 92.5W and 95W. Otto is forecast to continue to weaken as the system moved westward. 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 Gulf of Tehuantepec area is supporting gale force winds in the 30-40 kt range over the Gulf of Tehuantepec with seas reaching 16 ft. The combination of high pressure weakening north of the area with Tropical Storm Otto weakening and moving west of the area will weaken the pressure gradient. This will help diminish winds below gale force over the Gulf of Tehuantepec by Sun afternoon. The area of high pressure will shift eastward over the southeast United States Sunday. This will help veer winds over the southwest Gulf of Mexico and further diminish winds funneling into the Gulf of Tehuantepec. Winds and seas will fall below advisory criteria Late Sunday night into early Monday morning as this gap wind event comes to an end. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The ITCZ extends from 06.5N102W to 06.5N107W to 09N116W to 09N123W to 12N133W to 09N140W. Scattered moderate isolated strong convection is from 08N to 17N between 123W and 133W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see above for more on the latest Gulf of Tehuantepec gale force gap wind event. Outside of the Gulf of Tehuantepec region, northwesterly swell dominates the offshore waters off the western coast of the Baja California peninsula with seas in the 7-9 ft range as depicted by the most recent altimeter passes. Seas are in the 4-6 ft range elsewhere over the open Pacific waters and 1-3 ft over the Gulf of California. Continued pulses of northwesterly swell will keep seas above 8 ft over the offshore waters off the western coast of the Baja California peninsula through the middle of next week. Winds will increase to near gale force in the Gulf of California north of 29.5N tonight through early Sunday both ahead of and behind a pre-frontal trough, with winds diminishing by Sunday afternoon. 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 Storm Otto. Otto will move west of the forecast waters today with winds and seas decreasing over the western forecast waters. Outside of the influence of Otto, light to gentle winds with seas in the 4-6 ft range prevail north of 10N, with moderate to locally fresh southwest flow and combined seas of 4 to 6 ft prevails south of 10N. Little change is forecast through the upcoming weekend and into early next week. REMAINDER OF THE AREA... A cold front is moving through the northwest waters with strong high pressure of 1031 mb building in its wake near 36N147W. The cold front has ushered in another set of long period northwesterly swell into the northwest waters with seas reaching near 13 ft according to a recent altimeter pass. Fresh to strong winds prevail west of the front as depicted by the overnight ASCAT pass. The pressure gradient between high pressure northwest of the area and lower pressure in the vicinity of the ITCZ is supporting a large swath of fresh to strong trades north of the ITCZ to near 22N and west of 130W. Combined seas over this are in the 9-12 ft range in a mix of northwesterly swell and northeasterly generated wind waves. The cold front will continue to propagate eastward over the northern waters over the next couple of days as strong high pressure builds in its wake. The building high pressure will further tighten the pressure gradient over the western waters north of the ITCZ with winds increasing to near gale force over this area later tonight. With a large fetch of strong to near gale trades combining with long period northwesterly swell, seas will build to near 15 ft over this area this weekend. $$ AL