000 AXPZ20 KNHC 041002 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Sat Feb 4 2017 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 0900 UTC. ...SPECIAL FEATURES... A Gale Warning is in effect for the Gulf of Tehuantepec. Strong high pressure building southward across the western Gulf of Mexico and the eastern slopes of the Sierra Madre Oriental mountains will continue to tighten the pressure gradient across the Isthmus of Tehuantepec during the weekend. This will result in the continuation of minimal gale force winds through late Sunday morning. Max seas in the vicinity of the Gulf of Tehuantepec will build to 11-12 ft with 8 ft seas propagating as far downstream as 10N100W. These combined seas will merge with seas generated in the Papagayo region by Saturday afternoon. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A surface trough axis extends from 01N89W to 01N100W. The ITCZ axis continues from 01N108W to 02N120W to 05N140W. No significant convection is noted. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A 1021 mb high pressure is centered west of Baja California near 28N127W. The high is maintaining mainly light to gentle winds across the offshore waters and seas of 4-7 ft...except for moderate NW to N winds within about 210 nm of the Baja coast between 24N and 30N as shown by scatterometer data. The latest altimeter pass continue to indicate seas of 7-8 ft in this region. Light to gentle NW winds prevail across the Gulf of California. The high will move towards the NE near 31N124W in about 24 hours maintaining its strength. The tightening of the pressure gradient between the high and a surface trough along western Mexico will support moderate to locally fresh northerly winds across the offshore waters W of Baja California Peninsula this weekend. Long period NW swell will continue to impact the offshore waters W of Baja California with seas building to 8 ft N of 25N through early Sunday morning then subsiding to 6-7 ft. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... The strong trade winds in the southwest Caribbean Sea will continue to funnel through the Central America gap regions to extend into the Gulfs of Fonseca, Papagayo, and Panama. The gap wind event in the Gulf of Papagayo is forecast to persist through Wednesday, with winds possibly reaching 30 kt this morning and again Sunday morning. Seas will build in and downstream of the Gulf to 9 ft. Fresh to locally strong NE winds are also expected across the Gulf of Fonseca and downstream to near 92W this morning. Northerly winds in the 20-25 kt range will continue to blow into the Gulf of Panama through Sunday morning. Northerly winds of 15-20 kt are expected thereafter. Otherwise, light and variable winds and 4-6 ft seas will prevail elsewhere. REMAINDER OF THE AREA... A broad surface ridge anchored by a 1021 mb high centered near 28N127W dominates the north waters, and extends a ridge axis SE to near the Revillagigedo Islands. The pressure gradient between the ridge and lower pressure in the vicinity of the ITCZ is producing an increase in the trade wind flow. The latest scatterometer data show an area of 20-25 kt NE-E winds from 08N to 14N between 119W AND 125W. Seas of 8-9 ft are noted within this area of the trades. Fresh to strong winds will persist N of the ITCZ through Tuesday as the high prevails nearly stationary. The next cold front will reach the far NW corner early Sunday morning. Fresh to strong southerly winds are expected to develop ahead of the front by early Sunday afternoon. By Sunday night the front will start dissipating and will move N of the area. However, long period NW swell with building seas up to 12 ft, will follow the front. Looking ahead...marine guidance suggests increasing winds and building seas across the NW corner of the forecast area by Monday night, ahead of a strong cold front. $$ NR