000 AXPZ20 KNHC 110240 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0410 UTC Tue Oct 11 2016 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 0200 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning...High pressure ridge extending southward across eastern Mexico and the western Gulf of Mexico continues to produce a fairly strong pressure gradient across the Isthmus of Tehuantepec, and will persist over the next several days. This will maintain strong northerly gap winds spilling across the Gulf of Tehuantepec for the next few days, with nocturnal drainage effects resulting in increased winds overnight to gale force through Tuesday morning. Winds remain at 20-30 kt this evening across the Gulf but will pulse to gale force again around midnight tonight through Tuesday morning. Computer models suggest that this cycle will repeat again each of the next few days, but with winds increasing and peaking at around 30 kt during the overnight hours. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 10.5N84.5W to low pres near 11N96.5W to low pres 13.5N120W to low pres near 11N126W to 08.5N134W to beyond 08.5N140W. Widely scattered moderate to strong convection is occurring N of 07N between 78W and 86W. Scattered moderate to strong convection is occurring from 10N to 15.5N between 94.5W and 103W. Scattered strong convection is occurring from 15N to 18.5N between 115W and 122W. Scattered moderate to strong convection is elsewhere within 120 nm of trough between 109W and 128W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A weak sub-tropical ridge axis extends northwest to southeast across the local Pacific waters from a 1017 mb high near 26N130W to near 21N110W off the southern tip of Baja California Sur. Light to gentle northerly breezes will persist across the region north of 20N through Tuesday, including the Gulf of California on the eastern periphery of the weak ridge. Winds off the coast of the Baja California peninsula will increase to 15 to 20 kt by Wednesday north of Cabo San Lazaro between building high pressure to the northwest and troughing over northwest Mexico. Elsewhere a light to gentle breeze, and 3 to 5 ft seas will persist. Scattered strong thunderstorms are occurring from offshore of the Gulf of Tehuantepec downwind to near 11N98W, where broad low pressure has developing along the monsoon trough near 11N96.5W. This active weather will shift westward and across 102W overnight. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Moderate southwest winds persist from 05N to the monsoon trough which is meandering east to west along roughly 10N to 11N, with a light to gentle southwest breeze farther south toward the Galapagos Islands. Seas are 4 to 6 ft south of the monsoon trough largely in long period southwest swell. Little change is expected with these observations through Wednesday. Clusters of widely scattered showers and thunderstorms are offshore of Central America north of 07N 78W and 86W. Fresh to strong winds are expected to pulse higher at night across the Papagayo region but will not extend more than 90 nm offshore. Broad low pressure associated with the monsoonal circulation across the SW Caribbean and Central America will produce light to moderate winds wavering from NW to N from Guatemala to offshore of the Gulf of Papagayo for the next few days. REMAINDER OF THE AREA... The 1017 mb high pressure centered near 26N130W will shift N to near 31N130W on Tuesday and maintain the weak ridge extending SE to offshore of Manzanillo. A stalled and weakening front hasbegun to dissipate from 30N136W to 27N140W with winds less than 20 kt on either side. Moderate NW swell generated behind this front has spread southeastward and well E of the stalled front, where seas are 8-10 ft NW of line from 30N133W TO 28N134W TO 22N140W based on afternoon altimeter data. The swell across this area will diminish in size through Tuesday as it continues propagating SE and merges with the trade wind belt. Seas will subside to less than 8 ft across these NW waters early on Wednesday. Areas of moderate to fresh trade winds persist north of the monsoon trough to near 20N, with seas of 5 to 7 ft. Increasingly favorable conditions aloft are expected to provide weak low pressure systems currently along the monsoon trough, one near 13.5N120W and the other one near 11N126W, to improve in organization during the next 48 hours, as they shift W-NW to NW. The pressure gradient between these lows and the ridge to the N will induce freshening winds across the N semicircles of these lows to induce increasing winds to 20-25 kt and seas 8-10 ft by late Wednesday. $$ Stripling