000 AXPZ20 KNHC 242135 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 UTC Mon Oct 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 Seymour is rapidly intensifying and it is expected to become a major hurricane tonight or Tue. At 24/2100 UTC, it is located near 15.3N 111.3W, moving west-northwest or 285 deg at 13 kt. Maximum sustained winds have increased to 85 kt with gusts to 105 kt. Minimum central pressure is 984 mb. Numerous strong convection is noted within 60 NM of the center of Seymour while scattered moderate to strong convection is seen elsewhere from 12N to 18N between 109W and 114W. Conditions remain favorable for continued intensification during the next few days as Seymour continues moving W-NW. A turn toward the northwest should occur by Wednesday. Although the forecast track keeps Seymour just outside of the Mexican offshore zones, fresh to strong winds and seas in the 8-10 ft range are expected to affect the southern part of zones PMZ023 through tonight and PMZ015 through late Tue. For additional details on Seymour, refer to the latest NHC forecast/advisory under AWIPS/WMO headers MIATCMEP5/WTPZ25. A gale warning will remain in effect for the Gulf of Tehuantepec during the next 48 hours, as strong northerly winds will persist throughout the week across this region. By Thursday night into early Friday morning, the aerial extent of the gale force winds will increase as high pres builds across the western Gulf of Mexico. At that time, seas are expected to build to 10-14 ft. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends across the Gulf of Panama near 08N79W to 07N90W to 09N100W. It resumes W of hurricane Seymour from a 1010 mb low pres near 18N118W to 1011 mb low pres near 15N127W to beyond 11N140W. Scattered moderate isolated strong convection is from 04N to 07N between 78W and 85W. Similar convection is from 06N to 10N between 98W and 102W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... See special features for details on the Gulf of Tehuantepec gap wind event. High pres of 1018 mb is centered near 27N120W and is producing light anticyclonic winds across the waters W of the Baja California Peninsula. Combined seas there are 4-6 ft across southern portions of the peninsula, and 5 to 8 ft N of 27N due to long period NW swell moving into the region. Seas here will subside below 8 ft by Tuesday. The high pres will shift slightly N-NE during the next 24 hours. This will result in moderate NW winds across the offshore waters. Inside the Gulf of California, mainly gentle southerly winds prevail across the north half, while gentle N to NW winds prevail across far southern portions. By this evening, gentle to moderate NW winds will dominate all the waters S of 27N extending SE to between Los Cabos and Las Tres Marias Islands. On Tuesday, as the high center shifts farther N-NE, NW winds will spill down the entire length of the Gulf of California. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo: Winds will pulse over the Gulf of Papagayo over the next couple of days. Winds will peak near 20 kt during the late night and early morning hours and diminish to near 15 kt during the afternoon and early evening hours. Elsewhere gentle to moderate S to SW winds are noted S of the monsoon, while mainly gentle W to NW winds prevail N of the monsoon trough. Combined seas are in the 4 to 6 ft range, primarily in long period SW swell which is dominating the offshore waters. These marine conditions will persist over the few days. REMAINDER OF THE AREA... A weak ridge dominates most of the north waters N of 20N, and is producing mainly light and variable winds between 20N and 30N. Outside Seymour, two weak low pres centers are noted along the monsoon trough near 18N118W and near 15N127W. Seas of 8-10 ft in NW swell are observed per a pair of altimeter passes N of 15N between 117W and 121W. Seas over this area are forecast to subside to less than 8 ft by Tuesday. A cold front is over the NW waters and extends from 30N135W to 28N140W. Moderate to fresh SW winds are noted N of 28N ahead of the front to 130W. This front will become stationary tonight extending from 30N134W to 27N140W. A second and stronger cold front will reach the NW waters by early Tue afternoon. The merging cold front is forecast to extend from 30N132W to 24N140W by early Wed afternoon. SW winds ahead of the second front will increase to 20-25 kt on Tue with seas building to 8-10 ft across most of the NW waters NW of a line from 30N131W to 27N136W. $$ GR