000 AXPZ20 KNHC 040306 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 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 0000 UTC surface analysis and satellite imagery through 0300 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 tighten the pressure gradient across the Isthmus of Tehuantepec this upcoming weekend. This is forecast to result in winds reaching minimal gale force this evening, and continues through Sunday morning. Max seas in the vicinity of the Gulf of Tehuantepec will build to 12-13 ft Saturday morning, with seas up to 8 ft propagating as far downstream as 10N100W. These combined seas will merge with seas generating in the Papayo region by Saturday afternoon. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A surface trough axis extends from 03N88W to 01N95W to 02N105W. The ITCZ axis continues from 02N105W to 03N125W to 06N140W. No significant convection is noted. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A 1020 mb high pressure is centered west of Baja California near 27N122W. 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 aboutb 200 nm of the Baja coast between 24N and 28N where an altimeter pass indicated seas of 7-8 ft. Light to gentle NW winds prevail across the Gulf of California. The high will move toward 30N124w in about 24 hours while slightly strengthen. The tightening pressure gradient between the high and a surface trough over 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 22N W of 116W by Saturday evening. Seas will subside to 6-7 ft by late Sunday. 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 reaching 25-30 kt Saturday morning and again Sunday morning and seas building in and downstream of the Gulf to 9 ft. Fresh to locally strong NE winds are aslo expected across the Gulf of Fonseca and downstrean to near 89W by Saturday morning. Northerly winds in the 20-25 kt range will continue to blow into the Gulf of Panama through Sunday morning, then 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... High pressure, with a couple of 1020 mb centers, dominates the north waters, and extends a ridge 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 most recent scatterometer data showed an area of 20-25 kt NE-E winds from 11N to 14N between 117W AND 123W. Seas of 8-9 ft are noted within the area of the trades. In addition, an area of sea heights of 8-9 ft will persist roughly betwen 05N-15N and W of 110W due to a mix of NW swell and shorter period wind waves. The next cold front will reach the far NW corner Saturday night. Fresh to strong southerly winds are expected ahead of the front over the NW waters by Sunday morning. Fresh to strong westerly winds and a new set of 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. $$ GR