000 AXPZ20 KNHC 040306 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 307 UTC Mon Mar 4 2019 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... Open East Pacific Waters Gale Warning: A cold front is expected to cross SE of 30N140W tonight, followed by a second reinforcing cold front expected to reach cross that area Mon afternoon. Fresh to strong winds will be associated with these fronts, which are forecast to merge by Tue morning. The associated low pressure will be near 32N140W by Mon evening with strong to near gale force winds and frequent gusts to gale force expected in the S semicircle, affecting mainly the waters N of 27N W of 130W late Mon through Tue, before the low lifts NE. A new set of long period NW swell is expected to invade the NW forecast waters on Mon night with seas of up to 16 ft. Conditions will improve by mid week. Gulf of Tehuantepec Gale Warning: A strong cold front moving across the Gulf of Mexico will force the next gap wind event across the Tehuantepec region beginning early Tue. Winds are forecast to start off as fresh to strong Tue morning and then will increase to gale force Tue evening through Wed night. Winds will drop below gale force late Thu morning but will remain strong through at least Thu night. Marine guidance suggests peak northerly winds in the 30 to 40 kt range will occur during this event. Seas are forecast to reach as high as 15 ft by Wed morning. 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 about these gale warnings. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The Intertropical Convergence Zone axis extends from 07N83W to 02N110W to 05N130W to beyond 04N140W. Scattered moderate convection is within 90 nm either side of the ITCZ axis between 83W and 89W, and between 94W and 104W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A ridge will dominate the offshore waters W of Baja California through Wed. The pressure gradient will tighten between the ridge W of Baja California and lower pressures over mainland Mexico tonight, resulting in fresh to strong winds through Mon. On Thu, a weakening cold front will reach Baja California Norte with minimal impacts. No large long-period swell is anticipated to affect the region through at least middle of the week. Gulf of California: Generally benign marine conditions are expected through early this week with mainly gentle to moderate winds. Wed night into Thu, a weakening front will reach the Gulf with brief fresh to strong SW flow N of 30N Wed night. Gulf of Tehuantepec: Please see the special features section above. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo: Fresh to strong winds in the 20 to 25 kt range are expected across the Gulf of Papagayo through Tue, but mainly at night with the assistance of the nocturnal drainage flow. An increase in the Caribbean pressure gradient will significantly boost winds across the Gulf of Papagayo Tue night through at least Thu night, when strong to near gale force winds are expected. Seas are forecast to peak around 11 to 12 ft Thu morning. Gulf of Panama: Moderate to fresh winds will prevail through Tue. A tightening pressure gradient from high pres building to the north will bring fresh to strong N winds in the Gulf Tue night through at least Thu night. Seas will build to around 9 ft Thu morning. Elsewhere, benign marine conditions can be expected through at least Thu night. No large long- period swell are anticipated to impact the waters for the next several days. REMAINDER OF THE AREA... Marine conditions will deteriorate N of 25N W of 125W Mon through Tue as low pressure and associated cold fronts affect the region. Please see the Special Features Section for more details. Long-period NW swell mixing with wind waves due to tradewind flow is maintaining an area of 7 to 9 ft seas from about 05N to 18N W of 125W. This swell will gradually subside to less than 8 ft through Mon. Then, a similar pattern of mixed NW swell and wind waves are expected to develop over roughly the same area late this week. $$ Latto