000 AXPZ20 KNHC 260220 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 UTC Wed Feb 26 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 0000 UTC surface analysis and satellite imagery through 0130 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Storm Warning: The next gap wind event over the Gulf of Tehuantepec is expected to commence on Wed afternoon as a strong cold front moving across the Gulf of Mexico reaches the Isthmus of Tehuantepec. High pressure building behind the front will provide a very tight pressure gradient over the area, and bring an increase in winds funneling into the Gulf of Tehuantepec. Winds will rapidly increase to gale force by late Wed afternoon, and then to storm force by Wed evening. Storm conditions are forecast to persist into early Fri, and the gale force winds are expected to continue into early Sun. Seas are forecast to build to 21-23 ft with this upcoming event by late Wed night. Marine interests transiting across or in the vicinity the Gulf of Tehuantepec should be aware of this very strong gap wind event, and take the necessary action to avoid these hazardous marine conditions. Gulf of California Gale Warning: A surface ridge extends across the offshore waters off the Baja California peninsula while a surface trough is located over western Mexico. The pressure gradient between these features is supporting fresh to locally strong NW-N winds across the Gulf of California. Late tonight through Wed, strong high pressure building across the Great Basin region of the United States will help to strengthen winds over the entire Gulf of California. Winds are forecast to increase to 20 to 30 kt, with seas building to 8 to 10 ft mainly S of 28N on Wed, except winds are now forecast to reach minimal gale force mainly in the central Gulf beginning late Wed morning through the early evening. Fresh to strong winds will also affect most of the Baja California peninsula, but particularly the northern part where gale force gusts may occur near and just onshore. Winds are forecast to diminish to 20 to 25 kt across the Gulf of California by Thu morning with seas of 8 to 9 ft S of 28N, with winds then diminishing to 20 kt or less by Thu afternoon. Please see the latest High Seas Forecast issued by the National Hurricane Center under AWIPS/WMO headers FZPN03/HSFEP2 NHC or at website https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml for further details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A surface trough extends from near the 09N83W to 08N90W to 03N101W. The ITCZ continues from 03N101W to 04N112W to 03N120W to 06N140W. Scattered moderate convection is noted from 04N to 06N between 112W and 115W, from 05N to 07N between 133W and 136W, and also from 02N to 06N between 138W and 140W. 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, and the developing Gale Warning in the Gulf of California. Elsewhere, high pressure prevails over the offshore waters W of the Baja California peninsula supporting moderate to locally fresh NW to N winds. A set of NW swell propagating across the waters W of Baja California has reached the Revillagigedo Islands with seas of 6-8 ft. Seas will start to subside S of Cabo San Lazaro on Wed. As winds increase in the Gulf of California, fresh to near gale force N-NE winds are expected to filter through the passages in Baja California into the Pacific offshore waters N of Cabo San Lazaro, and gale force gusts may occur near and just onshore. This will keep seas in the 8 to 11 ft range N of Cabo San Lazaro through early Thu. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Large and fresh NW swells generated by a storm force gap wind event in the Gulf of Tehuantepec NW of the area will propagate into the offshore waters of Guatemala and El Salvador by early Thu and continuing into the upcoming weekend before subsiding Sun. Seas will reach to 16 ft along the offshore boundary of the Guatemala/Mexico border. Gulf of Papagayo: Mainly light and variable winds and 4-6 ft seas in mixed swell prevail. High pressure will build N of the area toward the end of the week, and winds will become offshore and increase to moderate to fresh on Thu, then fresh to strong Thu night. Strong to near gale force winds are then expected on Fri, possibly reaching minimal gale force during the upcoming weekend. Gulf of Panama: Mainly moderate northerly winds will increase to fresh to strong across the Gulf of Panama and downstream to near 04N or 05N beginning on Fri as high pressure builds N of the area. These winds will continue to pulse through the upcoming weekend. Elsewhere, gentle to moderate winds and seas of 4-6 ft in mixed, long period swell will prevail the remainder of the week. REMAINDER OF THE AREA... Seas of 8 ft or greater prevail over much of the forecast waters W of 112W in a broad mix of swells. Another set of long period NW swell will reach the NW waters on Wed and spread SE. Seas will peak around 11-12 ft over the far NW waters Wed night before starting to subside. A ridge extends from high pressure of 1034 mb centered N of the area near 37N132W, to near the Revillagigedo Islands. The pressure gradient between this area of high pressure and lower pressure in the vicinity of the ITCZ is supporting fresh tradewinds N of the ITCZ to near 20N and W of 125W. Seas in the 8-10 ft range prevails over this area in mixed NW swell and NE wind waves. While the area of high pressure will begin to weaken tonight into early Wed, weak and broad troughing along the ITCZ will help to increase the pressure gradient resulting in an area of fresh to strong trades by early Wed evening, mainly from 08N to 15N between 123W and 135W. Looking ahead, new and stronger high pressure will build NW of the area this weekend with a large area of fresh to even near gale force trades developing over the W-central waters. $$ Lewitsky