000 AXPZ20 KNHC 121600 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Fri Jan 12 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 1545 UTC. ...SPECIAL FEATURE... Gulf of Tehuantepec Storm Warning: Minimal gale force northerly winds at sunrise this morning will quickly increase to 35-40 kt strong gale conditions by this evening. A reinforcing northerly surge on Sat morning will increase these gap winds to minimal 35 to 50 kt storm force by Sat evening, with seas building to a maximum of 24 ft downstream of the gulf waters near 14N95.5W on Sat night. Winds are not forecast to diminish below gale force through at least Thu morning. INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A surface trough extends W from the Pacific coast of Colombia at 07N78W to 07N110W where scatterometer winds indicate a transition to an ITCZ, which continues WNW to beyond 09N140W. Isolated moderate to strong convection is noted within 120 nm either side of a line from 08N82W to 06N95W to 07N107W, in an isolated cluster within 45 nm of 06.5N123W, and across the tropical waters from 09N to 12N W of 135W. Scattered moderate isolated strong continues from 12N to 17N between 129W and 137W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... See special features section for information about a storm warning in the Gulf of Tehuantepec. Moderate northerly winds and 6 to 9 ft seas in 9 second long period NW are expected across the Pacific waters W of the Baja Peninsula through this evening, then winds will diminish to a gentle variable breeze around a weak N to s orientated trough develop along 114W. The trough will shift slowly W through the upcoming weekend and dissipate along 119W late Mon. Seas will subside to 4 to 7 ft on Sat night, but build back to 8 to 13 ft N of 24N on Mon through Tue in 22 second long-period NW swell. Gulf of California: Strong NW winds, and 6 to 9 ft seas, will continue across the gulf waters from 24.5N to 28.5N into this evening then winds will diminish to a moderate to locally fresh NW breeze that will continue through late Tue. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulfs of Papagayo and Fonseca: Moderate to locally fresh NE winds are expected this evening, increasing to a strong NE breeze surging across the Gulf of Papagayo around sunrise on Sat. These strong wind conditions will spread N across the Pacific waters to the N of 11N and E of 92W, including the Gulf of Fonseca waters, beginning on Sat evening and continuing through Sun morning. The NE winds will increase to near gale force in and downstream of the Gulf of Papagayo on Sat night and continue through Mon afternoon. The resultant area of 7 to 11 ft NE swell will merge with N swell propagating S from the Gulf of Tehuantepec gap event on Sun. Elsewhere, light to moderate SW winds will persist S of Costa Rica and Panama through Sat with seas generally between 3 and 5 ft. Fresh N winds are forecast across the Gulf of Panama beginning on Sat evening, continuing through sunrise on Mon. REMAINDER OF THE AREA... The pressure gradient between a high pressure center meandering near 32N130W, and broad low pressure across the deep tropics, is supporting fresh NE trades from 09N to 19N between 120W and 140W. NW swell in the form of 6 to 9 ft seas is currently observed across the Pacific waters N of 08N W of 115W. These seas will continue to subside from the E through Sat. Strong to near gale force southerly winds will develop across the waters from 29N to 32W W of 138W on Sat, in advance of a strong cold front that will reach 32N140W on Sat night. Although the front will stall from near 32N125W to 27N140W on Tue, large 12 to 22 ft seas in long period 17 to 22 second NW swell, will propagate SE across the discussion area on Tue and Wed. A secondary cold front will reach 32N140W on Sun night driving seas back up to 22 ft along 32N. $$ Nelson