000 AXPZ20 KNHC 120342 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 UTC Sat Sep 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 0250 UTC. ...SPECIAL FEATURES... A 1006 mb low is centered along the monsoon trough near 15N109W, and anchors the eastern end of an elongated cyclonic circulation in the lower atmosphere that extends W-NW to a second surface low of 1008 mb near 17.5N118.5W. A large area of disorganized weather is persisting west of the 1006 mb, where scattered moderate to strong convection is occurring from 09N and 20.5N between 108W and 116W. Afternoon ASCAT data depicted a very broad cyclonic circulation about the low and monsoon trough, with peak winds around 20 kt and seas 6-7 ft between the low and the coast of western Guerrero, and winds of 15-20 kt in the SW quadrant between 60 to 330 nm from the center, where seas are 6-8 ft. Environmental conditions appear conducive for development of this system, and a tropical depression is likely to form over the weekend or early next week while the system moves west- northwestward away from the coast of Mexico. The system has a high chance of developing over the next two days. For more information, see the latest Tropical Weather Outlook at https://hurricanes.gov. ...TROPICAL WAVES... A tropical wave extends along 86W north of 03N to across Central America, moving westward at 10-15 kt. Scattered moderate to strong convection ahead of the wave has been occurring over land and is shifting partially over water, extending to within 150 nm of the coast between 85W and 89W. A tropical wave along 111W/112W has become absorbed within the elongated cyclonic circulation described above, connecting two surface low pressure centers. See the Special Features section above. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from 10.5N73W to 09N84W to low pres near 15N109W 1006 MB to low pres near 17.5N118.5W 1008 MB to 11N140W. Scattered moderate isolated strong convection is noted from 07.5N to 13N between 90W and 103W. Scattered moderate to strong convection is noted extending within 150 NM off the coast between 85W and 95W, from 08N to 12.5N between 97W and 104W, from 09N and 20.5N between 108W and 116W, from 11.5N and 13N between 116W and 121W, from 17N to 20N between 118W and 121W, and from 08.5N to 13N W OF 131W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... See Special Feature discussion of low near 14N107W. Generally tranquil marine conditions are expected across the offshore waters for the next several days as a weak pressure gradient prevails. However, the low pressure near 15N109W is expected to gradually become better organized and will increase winds and seas across the outer waters from offshore of Manzanillo, shifting west-northwest to the Clarion Island area. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, and WITHIN 750 NM OF ECUADOR... Tranquil conditions should prevail for the next several days with light to gentle winds north of the monsoon trough along about 10N, and gentle to moderate south to southwest winds south of the monsoon trough. No significant long-period swell is expected to impact these waters during the next several days, although small swell will continue to impact the waters for the next several days. REMAINDER OF THE AREA... Low pressure of 1008 mb is centered southwest of the Clarion Island near 17.5N118.5W. Scattered moderate to strong convection is within 180 nm of the low in the NW quadrant. Afternoon ASCAT data indicated a broad and weak cyclonic circulation consisting of gentle to moderate winds within about 210 nm of the low in the western semicircle. Some development of this system is possible during the next few days before it interacts with, and possibly becomes absorbed by the larger weather disturbance to its east discussed in the Special Feature section. High pressure of 1020 mb centered near 32N132W dominates the waters north of 20N, west of 120W. Gentle to moderate northeast trades continue north of the monsoon trough axis with seas 5-7 feet. Moderate to fresh south flow persists south of the trough with 5-7 ft seas. Long-period south to southwest swell is present east of 120W, contributing to combined seas of 6-8 feet near the equator. Seas will subside slightly through Tue, however wave model guidance suggests that new south to southwest will be moving through waters south of the Equator and east of 120W during the early to middle part of next week. $$ Stripling