000 AXPZ20 KNHC 220403 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 UTC Fri Dec 22 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 FEATURE... ...Eastern Pacific Ocean Gale-Force Winds... Low pressure developing just east of Hawaii will intensify as it tracks NE, clipping our area of discussion near 30N140W Saturday morning. Forecast models are in good agreement on gale-force SE to S winds developing to the east of the low center early Saturday, persisting over our waters N of 28N and W of 138W until Saturday afternoon, when the low will track north of 30N and away from our discussion waters. Sea heights ranging from 13 to 15 ft will be likely with the gale-force wind conditions. Please read the latest high seas forecast under AWIPS/WMO headers HSFEP2/FZPN03 for more details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... TROUGH FROM 05N77W TO 07N87W TO 06N97W TO 08N104W. ITCZ CONTINUES FROM 08N105W TO LOW PRES NEAR 11N113W 1010 MB TO 10N126W BEYOND 09N140W. SCATTERED MODERATE ISOLATED STRONG WITHIN 480 NM N OF ITCZ BETWEEN 107W AND 118W...AND WITHIN 120 NM S OF ITCZ BETWEEN 117W AND 120W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Gulf of California: The cold front has dissipated as of the map analysis at 22/0000 UTC. Fresh to strong NW winds are behind the front. These winds will continue to spread south across the Gulf during the rest of the late night hours of Thursday, into Friday, reaching as far to the south, as San Jose del Cabo Friday night. Peak wave heights should range from 7 feet to 8 feet on Friday in the central Gulf. Some fresh-to-briefly strong winds will emerge over the Pacific coast of Baja California in the gaps between the highest terrain. Conditions will improve through Sunday with generally benign conditions thereafter through Tuesday. Gulf of Tehuantepec: A new Tehuantepec gap wind event should start Saturday night, due to a strong cold front that will be pushing across the Gulf of Mexico. Model consensus indicates that the wind speeds will increase to 20 to 30 kt early Sunday morning, with gale force winds beginning Sunday night, and continuing through Tuesday afternoon. Winds should peak before daybreak Monday and again Tuesday morning between 35-40 kt. 13 ft seas or greater are likely to occur on Monday and Tuesday in the Gulf with maximum seas around 14 ft early Tuesday. An area of sea heights reaching 8 feet starts from 28N northward between 117W and 124W. This area of seas eventually disappears before sunrise on Friday. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... The next round of a Gulf of Papagayo event will start on Sunday morning, and continue until Wednesday around noon. The sea heights should remain less than 8 feet through Sunday, and peak at 8 feet on Wednesday and Thursday. REMAINDER OF THE AREA... Mainly moderate-to-fresh east to northeast winds prevail in the waters from the ITCZ to 30N, driven by high pressure centered to the north of the region. These winds support 6 to 8 ft seas in a NW swell. Winds become northerly N of 25N and E of 125W. Sea heights to the N of 27N are remaining in the range of 7 to 8 ft into early Friday morning. To the south of the ITCZ, gentle to moderate SE winds prevail with seas of 5 to 7 ft. High pressure will build SE toward California on Friday while low pressure currently developing west of our waters just east of Hawaii tracks NE. The pressure gradient between these two features will support fresh to strong SE winds north of 20N and west of 135W beginning Friday. Models have trended slightly stronger with this system since yesterday, with SE to S winds of 20 to 30 kt along with a small area of gale force winds now expected late Friday night through Saturday N of 24N and W of 133W, as the low clips the corner of our area of discussion near 30N140W. Seas of 8 to 15 ft are expected during this time period over these affected waters. Please read the special features section for more details. The low will lift well to the north of 30N Saturday night with improving winds over our waters. NW swell of 8 to 10 ft will continue to propagate away from the departing system Sunday through Monday, reaching as far SE as 10N and as far east as 125W by Monday night, before the swell begins to decay to less than 8 ft. $$ mt