000 AXPZ20 KNHC 091612 CCA TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Fri Sep 9 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 1200 UTC surface analysis and satellite imagery through 1500 UTC. ...SPECIAL FEATURES... A low pressure center is estimated near 10.5n110w at 1009 mb, and associated with a tropical wave along 109W-110W. The tropical wave is moving west at around 5-10 kt, while the surface low appears to be drifting westward at 5 kt or less. Convection continues to become a little better organized this morning, with scattered moderate to strong clusters found within 90 nm across the NE and 210 nm across the NW quadrants of the low. Associated winds are currently around 20 kt or less, but these fresh winds are helping to support combined seas of 8-9 ft on the southeast sides of the low. Winds are forecast to gradually increase through the next 48 hours as this system continues to move generally westward. The low has a medium chance for tropical cyclone development during the next 48 hours. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from 12.5N93W to low pres 1009 mb near 10.5N110.5W to 14.5N122W to beyond 12.5N140W. Scattered moderate to strong convection is north of 03.5N and east of 92W, and also within 210 nm either side of the trough between 97W and 118W. Widely scattered to scattered moderate to strong convection is within 90 nm N and 120 nm S of trough between 122W and 139W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... The NE Pacific high extends a sub-tropical ridge axis from a 1033 mb high center near 42.5N141W southeastward into the region through 30N135W across the western portion of the offshore zones west of the Baja Peninsula to Las Islas Revillagigedo near 18N11W. Gentle to moderate northwest wind flow is expected across the Pacific waters of the Baja Peninsula through the period, except moderate to fresh northwest winds are expected to pulse along the central and northern portions through the upcoming weekend. The typical thermal trough will meander over the Baja Peninsula and across the northern Gulf of California for the next several days. This will maintain light and variable flow across the Gulf of California through the weekend. Low pressure may drop south along the trough into the northern Gulf of California Monday night through Tuesday night, increasing southerly winds on the southeast side of the low, and across the northern Gulf to moderate to fresh. Light and variable winds prevail across the waters between Cabo Corrientes and Puerto Angel this morning, while a nocturnal pulse of northerly winds across the Gulf of Tehuantepec overnight had diminished to 15-20 kt this morning. Seas there are 5-8 ft but will fall to 5-6 ft through tonight. Winds willremain variable across this central portion of the Mexican coastal waters during the next few days, while nocturnal pulses of moderate to fresh north winds are expected across Tehuantepec each night. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Light and variable winds are forecast to the north of about 09N through the period, while moderate southwest to west flow is expected across the waters generally to the s of 09N. Combined seas of 4 to 7 ft are forecast across the entire waters through the period, primarily in long-period southwest swell. REMAINDER OF THE AREA... A weak 1014 mb low pressure center is analyzed near 31N125W, andis helping to block the NE Pacific ridge from building fully into the Baja Peninsula waters. This low will gradually dissipate to a trough through the next few days with the ridging holding in place. Another weak 1011 mb low pressure area is analyzed near 18.5N125W moving west at around 10 kt. Recent altimeter data indicated seas of 8-9 ft within 360 nm across the northeast quadrant. The low is forecast to dissipate with a remnant trough left behind later today. Seas will also subside to less than 8 ft shortly after that time. Elsewhere, moderate NE winds prevail across the far NW waters, under the influence of the NE Pacific ridge, where seas are running 6-8 ft in NE wind waves and mixed swell. The ridge will generally remain intact for the next few days, with seas subsiding very slightly to 5-7 ft. $$ STRIPLING