000 AXPZ20 KNHC 010949 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Sat Dec 01 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 0600 UTC surface analysis and satellite imagery through 0945 UTC. .INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends W off the Pacific coast of Colombia at 07N78W across the northern Gulf of Panama to the Pacific coast of Costa Rica at 09N83W, then continues NW to 14N98W, then turns SW TO 11N104W to 09N119W where scatterometer winds indicate a transition to an ITCZ which continues W-SW to beyond 07N140W. Isolated moderate to strong convection is observed within 150 nm either side of a line from 06N78W to 05N83W to 16N99W. Scattered moderate isolated strong convection is noted within 120 nm either side of a line from from 12N103W to 08N122W to 08N132W to 07N140W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Gulf of California: Gentle to moderate variable winds are expected across the entire gulf through early Mon when a fresh NW breeze will develop across the central gulf waters and continue through early Tue. Gulf of Tehuatepec...Light to gentle, mostly onshore, flow forecast till late Mon night when fresh northerly drainage flow will develop. Strong to near gale force winds expected on Tue morning, and minimal gale force conditions expected on Tue afternoon, with a tightening pressure gradient supporting 35 to 40 kt gale conditions on Tue night into early Wed. Seas are expected to build to 15 ft downstream near 15N95.5W on Wed. Elsewhere: Fresh to locally strong NW flow expected W of the Baja Peninsula through Sun night. Long period NW swell is mixing with long period cross-equatorial southerly swell, resulting to combined seas of 8 to 15 ft across the offshore Pacific waters N of 12N. The highest seas are N of 24N in predominately NW swell. These seas will gradually subside to less than 8 ft by late Mon afternoon. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Volcanic ash originating from the Fuego Volcano in Guatemala may be reaching the Pacific waters within 30 nm of the central Pacific coast of Guatemala through the next 24 hours. Mariners should exercise caution. Gulf of Papagayo...Pulses of fresh NE winds expected through Sun morning, with these conditions resuming on Mon night and continuing through Wed. A strong gap event is forecast on Wed night through Fri with seas building to 8 ft. Elsewhere: The monsoon trough will meander between 08N and 11N through at least the middle of next week. Light to locally moderate northerly flow, and 3 to 5 ft seas, is forecast N of the monsoon trough, with moderate southwesterly monsoonal flow, and 4 to 6 ft seas, forecast S of the monsoon trough. REMAINDER OF THE AREA... A NW to SE ridge extends from 32N140W to 12N104W. Long period NW swell is mixing with long period cross-equatorial southerly swell, resulting in combined seas of 8 to 15 ft across the discussion waters W of 97W. The NW swell is building the highest seas N of 24N. These seas will continue to subside from the W to less than 8 ft by late Mon across the waters E of 125W. Fresh to strong southerly winds will develop N of 27N W of 137W tonight, with seas 8 to 12 ft reaching 30N140W around sunrise on Sun ahead of a cold front that will reach a position from 32N137W to 29N140W late Sun. The front will reach from 32N128W to 22N137W early Tue, preceded by strong SW flow N of 29N within 240 nm E of the front, and fresh to strong westerly winds and large 8 to 18 ft seas W of the front in long-period NW swell. $$ Nelson