000 AXPZ20 KNHC 040841 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Sat Jan 4 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: A pair of cold fronts will cross the SW Gulf of Mexico today. Northerly winds of fresh to near gale force are already blowing in the immediate Gulf, reaching gale force by 0900 UTC, and then rapidly reaching minimal Storm force this afternoon into early Sun before diminishing back to gale Sun morning. Winds should decrease to below gale force by Mon afternoon, but may quickly return to near storm force Tue afternoon. Seas will peak higher than 20 ft during this event and produce a wide swath of seas 8 ft and greater in wind driven N swell. 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 Panama/Colombia border at 09N78W to 1014 mb low pressure near 10N94W to 07N108W to 08N116W. The ITCZ continues from 08N116W to 06N129W to 07N140W. Scattered moderate convection is noted within 17N110W to 10N110W to 04N119W to 08N125W to 17N110W, and also within 08N140W to 06N133W to 03N132W to 05N140W to 18N140W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please read the Special Features section for more details about the developing Storm Warning in the Gulf of Tehuantepec. Gulf of California: Moderate to fresh NW to N wind flow prevails, along with seas of 3 ft or less in the northern Gulf, and 4-6 ft seas in the central and southern portion. Winds will pulse to locally strong in the central and southern waters today, then will increase to fresh to strong across the entire basin by early Mon as the pressure gradient tightens, diminishing by early Wed. Corresponding seas are expected to build to between 6 and 9 ft. Long period NW swell continues to propagate SE across the regional waters, with seas running 6-9 ft across the offshore waters of Mexico. Seas will slowly subside through Sun. Associated large breaking waves may produce dangerous surf conditions along exposed coastlines through early today. A new set NW swell will arrive offshore of Baja California Norte Sun, subsiding Tue, with yet another set arriving Wed night. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo: Moderate to fresh offshore gap winds will increase to fresh to strong by the upcoming evening. These winds are forecast to persist through the upcoming week, potentially reaching near gale force by Wed. Elsewhere, gentle to moderate S to SW flow will continue over the offshore waters of Costa Rica, Panama, Colombia, and Ecuador through the middle of next week, except for moderate to occasionally fresh N flow across the Gulf of Panama. Large fresh NW swell generated by the storm force gap wind event in the Gulf of Tehuantepec mentioned above will impact the offshore waters of Guatemala and El Salvador tonight through early Mon. Long period NW swell will move SE across the offshore waters through Sun. This very long period, high energy NW swell is reaching the Galapagos Islands and will arrive on the coasts of Costa Rica, Panama, and Columbia later today, producing large and dangerous surf conditions. REMAINDER OF THE AREA... A cold front cuts across the NW corner of the discussion area from 30N134W to 26N140W. Fresh to strong NE winds are behind the front as sampled by recent scatterometer passes. Ahead of the front, mainly moderate to fresh trades prevail N of the ITCZ along with 8-10 ft seas with some old background NW swell according to recent altimeter data. The front will stall and gradually dissipate across the NW waters through Sun night. High pressure building in the wake of the front will generate fresh to strong NE winds across the northern and W-central waters by the end of the weekend, and seas building to between 8 and 13 ft. Winds and seas E of 130W will gradually diminish and subside by mid week. $$ Lewitsky