000 AXPZ20 KNHC 130905 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0900 UTC Wed Feb 13 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 0600 UTC surface analysis and satellite imagery through 0900 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: High pressure building southward over eastern Mexico in the wake of a cold front is helping for gale force winds across the Gulf of Tehuantepec. Winds are expected to peak near 40 kt by early this morning. Winds will diminish below gale force early Thu, and further diminish to 20 kt or less later in the day on Thu. Associated seas with this event are expected to peak near 18 or 19 ft today. Eastern North Pacific Gale Warning: A tight pressure gradient between a ridge of high pressure W of the Baja California peninsula and low pressure of 996 mb centered N of the area near 32N133W is producing gale force winds N of 25N between 125W and 131W. A cold front extends from the low across the NW waters from 30N138W to 28N140W. Gale force winds prevail W of the front. Low pressure will shift further N today. This will loosen the pressure gradient over the forecast area and diminish winds below gale force. The cold front has ushered in a fresh set of long- period northwest swell, with seas peaking near 18 ft W of the front. The swell will propagate southeastward, while slowly subsiding over the next several days. Please read the latest High Seas Forecast issued by the National Hurricane Center under AWIPS/WMO headers FZPN03/HSFEP2, or at the website https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml for more details on both of these gale warnings. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A surface trough extends from 06N77W to 05N87W. The ITCZ extends from 05N87W to 02N112W to 08N140W. Scattered moderate isolated strong convection is noted within 30 nm S of the ITCZ between 91W and 94W. Scattered moderate isolated strong convection is noted within 30 nm N of the ITCZ between 97W and 101W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see above for more on the upcoming gale force gap wind event in the Gulf of Tehuantepec. A weak pressure gradient W of Baja California is resulting in light to gentle winds across the offshore waters of Baja California, with seas of 4 to 7 ft in northwest swell. A cold front will move into the far northern waters west of Baja California Norte late Thu. The front will dissipate across central Baja and the Gulf of California on Fri. Gentle to moderate winds will prevail W of the front. Seas will build to near 16 ft W of Baja California Norte this weekend as NW swell propagates into the area. Elsewhere, light to gentle breezes and seas in the 4 to 6 ft range will prevail between the Gulf of Tehuantepec and Cabo Corrientes through the forecast period. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Moderate to fresh winds over the Gulf of Papagayo will pulse to strong during the overnight hours through Fri. Gentle to moderate northerly winds will continue over the Gulf of Panama through Sat, becoming gentle Sat night. Light to gentle winds will prevail elsewhere across the forecast waters. REMAINDER OF THE AREA... Please see above for more on the gale force winds over portions of the discussion waters N of 22N and W of 125W. Elsewhere, long-period northwest swell continues across the forecast waters, mixing with long-period cross equatorial southwest well. Seas of 8 ft or greater prevail over much of the waters W of 120W, with another area of 8 to 9 ft seas covering much of the waters from 00N to 10N W of 115W. Areal coverage of seas greater than 8 ft will continue to decrease today. Satellite imagery shows ample deep layer moisture in the form of mostly mid and upper-level clouds, streaming northeastward W of a line from Baja California Norte to 10N132W, in strong southwest mid and upper- level flow. This flow is located ahead of an upper level trough axis extending from the NW United States SW to just N of Hawaii. The upper level trough supports the complex low pressure system mentioned above under the Special Features section. Areas of rain along with embedded showers and isolated thunderstorms within these clouds, and are expected to last through the end of the week, and gradually shift into California. $$ AL