000 AXPZ20 KNHC 181552 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Sun Nov 18 2018 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. .INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 09.5N75W TO 06N79W TO 09.5N84W TO 06N95W. The ITCZ extends from 06N95W to 09N99W to low pres near 10N121W then trough to low pres near 09.5N132W, then ITCZ to beyond 10N140W. Scattered moderate to strong convection is noted from 03N to 07.5N between 77.5W and 83W, and from 06N to 13N between 108W and 137W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Gulf of Tehuantepec: Strong northerly winds will continue across the gulf waters as far S as 14.5N95W through Tue, and will pulse to around 30 kt each night through early morning. Model guidance suggests stronger drainage flow on Tue evening through night, as a cold front moves into the western Gulf of Mexico. This is expected to produce minimal gale force conditions through Wed morning, then return to fresh to strong Wed through Thu night. Gulf of California: Light and variable winds are expected through this evening. Moderate NW winds are forecast across the entire gulf waters by tonight into Mon morning, then the pressure gradient will relax with light NW flow through Wed morning. High pressure will build across the region Wed night and Thu behind a dying cold front sweeping eastward into the area, which will induce freshening NW wind flow across most of the Gulf. A weak NW to SE ridge extends across the Mexican offshore waters W of 100W, with gentle to moderate anticyclonic flow forecast around the meandering ridge through Wed morning. A decaying cold front will approach Wed afternoon, with stronger ridging building in the wake of the front through the end of the week, ushering in fresh NW-N flow and building NW swell. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo: Fresh to locally strong NE winds, with seas building briefly to 8 ft downstream, are expected through the next several days. Light to locally moderate northerly flow is forecast elsewhere N of the monsoon trough, while moderate southwesterly monsoonal flow, with 4 to 6 ft seas, is forecast S of the monsoon trough through the next several days. REMAINDER OF THE AREA... A cold front extends from 30N134W TO 23N140W accompanied by a fresh SW-W-NW wind shift, and 8 to 10 ft seas W of the front in long-period NW swell. The front will weaken as it approaches the Baja Peninsula on Wed night, with several reinforcing boundaries rotating through the northern waters around a parent low pres area N of the discussion waters. The associated initial NW swell will subside to less than 8 ft on Mon night, with additional NW arriving Tue night. This set will be larger with seas up to 12 to 13 ft along 30N Wed and Wed night. A 1011 mb surface low is analyzed at 10N121W, and is embedded in a zone of fresh E to NE tradewinds to the north of the low, which is also within an area of long period northeasterly swell that is mixing with cross-equatorial swell across the waters generally S of 17N between 105W and 125W. This swell will gradually subside to less than 8 ft by the middle of the week as the surface low progresses westward. Model guidance suggests that an elongated trough will extend N-NE from this low through the next several days. This trough combined with building high pres across the northern waters will tighten the pres gradient and increase trades to fresh to strong NW of the trough axis late Tue night through the end of the week. $$ Stripling