000 AXPZ20 KNHC 050850 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Sun Jan 5 2020 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 0830 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Storm Warning: Powerful high pressure remains just N of the area with storm force northerly winds funneling into the immediate Gulf of Tehuantepec as captured by overnight scatterometer data, with a large surrounding area of gale force winds. Winds are in the process of diminishing from storm force to strong gale force early this morning. By midday Monday, winds are forecast to diminish below gale force. Gale force winds are then forecast to return by early Tue, with near storm conditions possible Tue evening, persisting through early Wed morning. Also, seas are up to around 25 ft with the storm force winds. A wide swath of 12 ft or greater seas will prevail over the area through Mon. Seas of 8 ft or greater may diminish some Mon night before new fresh swell is generated from the returning gale force winds on Tue. Please read the latest High Seas Forecast issued by the National Hurricane Center under AWIPS/WMO headers FZPN03 KNHC/HSFEP2 or at website https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml for further details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from near the W coast of Colombia at 05N78W to 08N95W to 05N102W. The ITCZ axis continues from 05N102W to 04N109W to 07N128W to 06N140W. Scattered moderate and isolated strong convection is noted from 06N to 12N between 97W and 102W, and also from 07N to 10N between 112W and 118W. Scattered moderate convection is noted from 06N to 08N between 135W and 140W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please read the Special Features section for more details about the Storm Warning in the Gulf of Tehuantepec. Gulf of California: Moderate to fresh winds through the remainder of the weekend will increase to strong by early Mon, then diminish Tue. Seas Mon and Tue will reach to near 8 ft. Remnant long period NW swell of 6-8 ft is decaying across the offshore waters of Mexico, and sea heights will continue to slowly subside today. New NW swell will arrive offshore of Baja California Norte later today, subsiding early Tue, with yet another pulse of swell arriving Wed. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Large fresh NW swell generated by the storm force gap winds in the Gulf of Tehuantepec mentioned above will impact the offshore waters of Guatemala and El Salvador through early Mon. Seas up to 12-15 ft, highest offshore of Guatemala, are forecast. Gulf of Papagayo: Strong NE to E winds will prevail through much of the week, with near gale force winds possible early this morning, and again early Wed. Gulf of Panama: Pulses of fresh wind will be common through the week. Elsewhere, gentle to moderate S to SW flow will continue over the offshore waters of and S of Costa Rica through the week, while very long period, high energy NW swell currently reaching and producing large and dangerous surf conditions at the coast will gradually diminish later today. REMAINDER OF THE AREA... An old frontal boundary in the far NW to N central waters has recently dissipated. Strong 1039 mb high pressure is just NW of the area near 35N142W with a ridge reaching SE of the high all the way to near 13N116W. A tight pressure gradient under this ridge exists, mainly N of 10N and W of 125W where fresh to strong trades are blowing as indicated by recent scatterometer data. Accompanying altimeter passes have sampled seas of 8-13 ft across this same area. The high and ridging will weaken through the early part of the week, allowing for trades to diminish which will assist in subsiding the accompanying seas. That will be short lived as the pressure gradient re-tightens by mid-week as a N to S trough propagates westward in the vicinity of the ITCZ. Developing gale force winds N of the area near Point Conception, California will generate fresh northerly swell which will push S into the area across our waters N of 25N and E of 125W by tonight through Mon night, causing seas to reach 12-15 ft. These conditions will improve by late Mon into Tue. $$ Lewitsky