000 AXPZ20 KNHC 301602 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Mon Sep 30 2019 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 1545 UTC. ...SPECIAL FEATURES... Tropical Storm Narda is centered near 22.5N 106.4W at 30/1500 UTC moving NW at 13 kt. Estimated minimum central pressure is 1000 mb. Maximum sustained wind speed is 35 kt with gusts to 45 kt. Numerous moderate to strong convection is from 21N to 24N between 105W and 108W. Scattered moderate convection is from 20N to 25N between 105W and 109W. The center of Narda will move over the Gulf of California near the coast of northwestern mainland Mexico through Tuesday. Some slight strengthening is possible today. Weakening should begin by Tuesday as Narda interacts with the mountains of western Mexico. Rainfall associated with Narda will cause life-threatening flash floods and mudslides, especially in mountainous terrain. Swells generated by Narda are affecting portions of the coast of southwestern Mexico. These swells are expected to spread northward and will likely cause life-threatening surf and rip current conditions along the west coast of mainland Mexico, along the east coast of Baja California Sur, and in the Islas Marias archipelago. See latest NHC forecast/advisory under AWIPS/WMO headers MIATCMEP1/WTPZ21 KNHC for more details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from near 07N78W to 08N87W to 14N92W, then resumes near 16N101W to 13N118W to 15N127W to a 1008 mb low pressure near 14N132W to 12N140W. Scattered moderate isolated strong convection is from 03N to 08N E of 90W, from 11N to 17N between 100W and 110W, and from 10N to 14N W of 136W. Scattered moderate convection is elsewhere from 11N to 16N between 122W and 134W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see the Special Features section above for information about Tropical Storm Narda. Seas across this area are running 8 to 11 ft, and generating very high surf across the coasts. Please refer to statements issued by the Meteorological Service of Mexico for more information. Elsewhere, surface high pressure W of 120W supports fresh to locally strong NW winds near the coast of Baja California north of Cabo San Lazaro. Associated seas ranging from 6 to 8 ft within the freshening flow are expected to subside by mid week as Narda dissipates inland Mexico, thus weakening the pressure gradient in the region. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Generally moderate W to NW winds prevail north of Costa Rica to Tehuantepec, while moderate S to SW winds are noted south of Panama and off the coast of Colombia. Seas of 8 ft in long period SW swell persist across the waters off Guatemala, El Salvador, and Nicaragua with seas in the 5 to 7 ft range elsewhere across the region. Seas will subside below 8 ft this afternoon. Fresh to locally strong SW monsoon flow will resume on Tue between Central America and the Galapagos Islands, with seas building to 8 to 9 ft offshore of Costa Rica and Panama. REMAINDER OF THE AREA... High pressure located well NW of the forecast area is building into the northern waters. This ridge is currently supporting moderate to fresh NE winds north of the monsoon trough W of 120W with seas in the 6 to 8 ft range. Elsewhere, 1008 mb low pressure analyzed near 14N132W along the monsoon trough is supporting fresh to locally strong SW winds and 8 to 10 ft seas within 390 nm S semicircle of the low. Some slight strengthening is possible while the system drifts slowly east to northeastward. Additional low pressure development is expected along the monsoon trough west of 130W during the next couple of days, which will likely maintain fresh SW winds and 8 ft seas over the far SW portion of the forecast waters. $$ Ramos