000 AXPZ20 KNHC 122147 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 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 1800 UTC surface analysis and satellite imagery through 2145 UTC. ...SPECIAL FEATURE... Gulf of Tehuantepec Storm Warning: Strong gale force northerly winds will increase to minimal 35 to 50 kt storm force by Sat evening, with seas building to a maximum of 25 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 Caribbean coast of Colombia at 09N77W across Panama to 08N83W to 06N95W where scatterometer winds indicate a transition to an ITCZ, which continues W through an embedded 1012 mb surface low at 07N110W to beyond 08N140W. Scattered moderate isolated strong convection is observed within 75 nm either side of line from 08N83W to 07N93W to 08N103W and from 07N129W to 08N137W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... See special feature section for information about a storm warning in the Gulf of Tehuantepec. Moderate northerly winds and 6 to 9 ft seas due primarily to 9 second long period NW are expected across the Pacific waters W of the Baja Peninsula through this evening, then winds will diminish becoming 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 25.5N to 27N 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... Gulf of Papagayo: Moderate to locally fresh NE winds are expected tonight, increasing to a strong NE breeze surging across the Gulf of Papagayo around sunrise on Sat. These NE winds will increase to near gale force surrounded by a larger area of frequent gusts to gale force, in and downstream of the Gulf of Papagayo on Sat night and continue through Mon afternoon, with a narrow swath of minimal gale force winds from near 10.5N to 10N87W late Sun night. Gulf of Fonseca: Strong N to NE winds will develop across the Pacific waters to the N of 11N and E of 92W, including the Gulf of Fonseca, beginning on Sat evening, and continuing through Sun morning. The resultant area of 7 to 11 ft NE swell from the gap winds 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 cold front that will reach 32N140W on Sat night. Although the front will nearly stall from near 32N125W to 27N140W on Tue, large 12 to 22 ft seas primarily due to 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