099 AXPZ20 KNHC 152205 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 UTC Sun Jul 15 2018 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 1800 UTC surface analysis and satellite imagery through 2100 UTC. ...SPECIAL FEATURE... A broad 1008 mb surface low is centered near 13N136W, embedded on a NNE-SW oriented trough. The ASCAT scatterometer passes around 18 UTC did not go through the center, though they did report peak winds of 40 kt with the system. However, these are rain inflated and not reliable. Peak sustained winds are likely 25-30 kt at this time. Additionally, a TOPEX altimeter pass around 15 UTC showed max seas of 8-10 ft. Scattered moderate and isolated strong convection is occurring within 180 nm of the system's center. The system's center should reach our western border at 140W by Mon morning and associated strong winds out of our area by late Mon. This system does have a moderate - 60 percent - chance of becoming a tropical cyclone within the next 48 hours. Refer to the EPAC Tropical Weather Outlook under AWIPS/WMO headers MIATWOEP/ABPZ20 KNHC for additional information. ...TROPICAL WAVES... A tropical wave extends from the eastern Pacific near 05N84W northward to over Central America to near 18N85W. The wave is moving W at 15-20 kt. The wave is identifiable from the Caymen Islands rawindsonde, the 700 mb trough diagnostics, and the total precipitable water imagery. Scattered moderate convection is occurring over Nicaragua and Honduras. A tropical wave is analyzed from 05N to 14N near 98W and is estimated to be moving W at 15 kt. The wave is only recognizable via the 700 mb trough diagnostics. No significant deep convection is associated with the system at this time. A tropical wave is analyzed from 05N to 15N near 107W and is estimated to be moving W at 15-20 kt. A 1011 mb low pressure center is analyzed to be along the wave's axis near 11N111W. This wave can be identified by a maximum in the total precipitable water imagery as well as the 700 mb trough diagnostics. Scattered moderate and isolated strong convection is occuring wihtin 180 nm of the low's center. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends W from a 1009 mb low near 10N75W over the coast of Colombia, across Panama, and to a 1011 mb low at 11N111W. The ITCZ axis extends from 11N111W to 09N128W. Isolated moderate convection is occurring within 180 nm S of the trough E of 95W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Gulf of Tehuantepec: Strong pulses of northerly gap wind flow is expected during late night and morning hours through Wed. Seas will peak at 8 to 9 ft. Conditions will subside on Thu and Fri. A surface ridge will meander across the area from 23N116W to 15N100W this week. Quiescent winds and seas prevail outside of the Gulf of Tehuantepec. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo: Moderate to strong late night/morning NE to E winds will occur across and within 180 nm SW of the Gulf of Papagayo through at least Thu night. Elsewhere winds and seas are quiet. The extended outlook is for long period southerly swell of 7 to 9 ft arriving along 03.4S E of 93W Wed and reach along 10N this coming weekend. REMAINDER OF THE AREA... Refer to Special Features section above for information on a weak surface low near 13N136W. A surface ridge will meander across the discussion area from 32N140W to 23N116W this week, with winds and seas remaining quiet over the remainder of the area. $$ Landsea