000 AXPZ20 KNHC 081603 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1258 UTC Sat Apr 8 2017 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...Minimal gale force northerly winds currently across the Gulf of Tehuantepec will diminish by mid morning, then to 20 kt or less within 12 hours. Seas up to 12 ft will gradually subside to less than 8 ft by then as well. Strong high pressure building southward over the Gulf of Mexico could bring gales back to the Gulf of Tehuantepec early on Thursday morning. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A surface trough extends from 08N85W to 03N92W to 05N107W. Scattered moderate and isolated strong convection associated with the trough is present within 180 nm either side of a line from 08N83W to 02N89W. A second surface trough stretches from 01S94W to 03S100W to 02S103W to 04S106W to 1009 mb low pressure near 03S108W. Scattered moderate and isolated strong convection associated with this trough is observed from 02S TO 03.4S between 99W and 105W. The ITCZ heads from 05N107W to 03N115W to 03N125W to 02N133W to beyond 02N140W. Scattered moderate and isolated strong convection associated with the ITCZ is occurring within an area bounded by 12N106W to 09N105W to 05N121W to 10N123W to 12N106W and from 02N to 06N between 126W and 134W. In addition, scattered moderate and isolated strong convection is taking place from 00N to 03.4S between 87W and 90W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... See the special features above for the ongoing Gulf of Tehuantepec gale force gap wind event. A weakening cold front lurks just W of the Baja offshore waters from 30N121W to 26N126W to 24N133W. Moderate NW to N flow this afternoon will become fresh across the waters offshore of Baja California Norte as high pressure builds E behind the front. Winds will be locally strong N of 27.5N and E of 117W. These conditions are forecast to spread SE across all waters W of the Baja Peninsula tonight, with seas building to 6 to 8 ft off Baja California Sur and 8 to 10 ft off Baja California Norte by Sun morning. The gradient will relax on Sun night, with moderate to locally fresh NW flow expected through the middle of next week as seas gradually subside to less than 8 ft on Tuesday morning. In the Gulf of California, light and variable winds are expected through tonight. Winds will gradually shift to the NW and increase to a moderate to fresh breeze across the waters N of 26N on Sun. These NW winds should diminish to a gentle breeze on Mon night. Smoke from agricultural fires over interior Mexico is observed on high resolution satellite imagery across the offshore waters to the N of 10N between 92W and 100W, and is estimated to be locally reducing surface visibility to between 3 and 5 nm. Expect improvement in conditions in about 18 hours. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... In the Gulf of Papagayo, fresh to locally strong nocturnal drainage winds expected through Sunday with the resultant NE swell propagating WSW to as far SW as 08N92W this evening. Winds could become fresh to strong again Tuesday night through Wednesday night. In the Gulf of Panama, N to NE winds will be moderate to fresh through Wednesday night. Elsewhere, gentle to moderate winds, and combined seas of 4 to 6 ft will prevail. REMAINDER OF THE AREA... A weakening cold front extending from 30N121W to 26N126W to 24N133W will sweep E across the discussion waters N of 25N. Large NW swell generated to the lee of the front will cause combined seas to build to 8 to 11 ft N of 20N and E of 130W. Another batch of NW swell, in the form of 7 to 10 ft seas, will propagate into the far NW portion Sun night through Tuesday ahead of a cold front that will approach 30N140W on Tuesday morning. Moderate to locally fresh NE trades will prevail across the tropics from 05N to 15N W of 110W through Tuesday. NE wind waves will combine with both NW and SW swell to generate an area of 6 to 9 ft combined seas across the tropics from 06N to 11N W of 128W this weekend. This area will persist into early next week. $$ cam