000 AXPZ20 KNHC 120310 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 015 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 0000 UTC surface analysis and satellite imagery through 0300 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: The next gale force gap wind event over the Gulf of Tehunatepec is expected to begin this evening as a cold front moving across the Gulf of Mexico reaches the Isthmus of Tehuantepec. The pressure gradient between high pressure building in the wake of the front, and the equatorial trough, will provide a tight pressure gradient to support gale force northerly winds funneling across the Gulf of Tehuantepec. Winds will rapidly increase to 30 to 40 kt tonight, with seas forecast to peak near 13 ft by sunrise Sun morning. Winds will diminish below gale force by Sun night. Then, strong to near gale force northerly winds are forecast to persist across the Tehuantepec region most of the forecast period, with gale conditions possible again by Thu night. 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 on this gale warning. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A surface trough extends from near 06N77W to 05N88W. The ITCZ continues from 05N88W to 05N110W to beyond 07N140W. Scattered moderate convection is noted within 120 nm N of the ITCZ W of 130W. 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 surface ridge extends SE across the offshore forecast waters W of Baja California to near 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 Sun. Seas associated to this swell event will peak near 14 ft W of Baja California Norte late Sun through Mon. This swell event will spread southward, with seas greater than 8 ft prevailing W of the entire Baja California peninsula by Tue. The pressure gradient is also supporting fresh to strong northerly winds across the southern Gulf of California, and also across the waters between Cabo Corrientes and Los Cabos. These winds will begin to diminish tonight. Seas across the southern Gulf of California and waters just south of Cabo San Lucas are in the 7-8 ft range, and will gradually subside through tonight as winds diminish. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Strong to near gale force winds will continue to blow across the Papagayo region as a strong wind flow in the SW Caribbean funnels through the gap. The winds are greatest during the overnight and early morning hours with the assistance of the nocturnal drainage flow. Seas will build to 8-11 ft each late night following the pulse of peak winds. This pattern will continue across Central America through Wed, supporting fresh to strong daytime winds pulsing to near gale force each night. The drainage flow will also aid fresh NE to E winds near the Gulf of Fonseca. 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. REMAINDER OF THE AREA... A surface ridge extends across the northern forecast waters from a 1039 mb high pressure located near 40N148W. 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 25N W of 120W. Seas are in the 9 to 12 ft range within this area of winds. These marine conditions are forecast to persist through the remainder of the weekend as the strong high pressure prevails NW of the forecast region. The aerial extent and strength of the trades will decrease some on Mon. New long-period NW swell currently reaching the NW waters will spread SE across the forecast area through early next week. Seas are forecast to peak 14 or 15 ft roughly N of 27N between 118W and 130W by Sun evening. $$ GR