000 AXPZ20 KNHC 121505 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1255 UTC Sun Jan 12 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 1200 UTC surface analysis and satellite imagery through 1500 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: The pressure gradient between high pressure along the Sierra Madre Oriental and the equatorial trough is supporting gale force northerly winds across the Gulf of Tehuantepec. Gale force winds will prevail through this evening before winds begin to diminish slightly to around 30 kt. Winds to near gale force will persist across Tehuantepec late tonight through Mon night before increasing again to minimal gale force briefly Mon night to Tue morning before diminishing. Strong to near gale force northerly winds are then forecast to persist across the Tehuantepec region most of the forecast period. Gulf of Papagayo Gale Warning: The pressure gradient between a ridge of high pressure N of the area and the equatorial trough is supporting strong to near gale force winds across and well offshore of the Papagayo region. This pattern will remain in place, with the strong to near gale winds persisting. Winds will briefly increase to minimal gale force Mon night with the combination of a slightly tighter pressure gradient between the ridge building N of the area along with enhanced offshore winds due to nocturnal drainage flow. Please see 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 on this gale warning. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A surface trough extends from near 06N77W to to 04.5N94W. The ITCZ continues from 04.5N94W to beyond 05N140W. Scattered moderate isolated strong convection is noted within 120 nm N of the ITCZ between 133W and 138W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see above for more on the latest gale force gap wind event in the Gulf of Tehuantepec. Elsewhere, a surface ridge extends SE across the offshore forecast waters W of Baja California to SE of the Revillagigedo Islands. The pressure gradient between this ridge and a trough over the Gulf of California will support moderate to fresh northerly winds W of Baja California through the forecast period. A set of NW swell will propagate through the waters off Baja California Norte today and build wave heights off of Baja California Norte, peaking near 13 ft by late this afternoon. This swell will spread southward while subsiding. Seas greater than 8 ft will prevail W of the entire Baja California peninsula by Tue. Elsewhere, variable winds at 10 kt or less generally prevail across the near and offshore waters from Manzanillo to Puerto Angel, where seas in the 4-6 ft range in NW swell. Northerly winds will gradually increase to around 15 kt across the Manzanillo area by Mon morning, but otherwise, little significant change is expected in marine conditions across the area for the next few days. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Please see above for more on the upcoming gale force gap wind event in the Gulf of Papagayo. Elsewhere, swell generated in the gap wind areas from Tehuantepec and Papagayo will propagate into the Guatemala and El Salvador offshore waters over the next several days to build seas to 6-8 ft. REMAINDER OF THE AREA... A surface ridge extends across the northern forecast waters from a 1040 mb high pressure located near 40N151W. The pressure gradient between the ridge and lower pressure in the vicinity of the ITCZ to the south of the ridge is producing a large area of fresh to strong trade winds that roughly covers the waters N of the ITCZ to about 28N W of 120W. The most recent altimeter passes indicate seas in the 9 to 12 ft range within this area of winds. These marine conditions are forecast to persist today as the strong high pressure prevails NW of the forecast region. The aerial extent and strength of the trades will begin to decrease Mon through Wed as high pressure starts to weaken and loosens the pressure gradient. Long-period NW swell propagating over the northern waters will spread SE across the forecast area through early next week. Seas associated to this swell are forecast to peak at 14 or 15 ft over the forecast waters roughly N of 27N between 118W and 130W by this evening. $$ AL