000 AXPZ20 KNHC 011558 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Fri Sep 01 2017 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 FEATURE... Tropical Storm Lidia is centered near 24.6N 111.2W, or 65 miles W-NW of La Paz Mexico at 1500 UTC, and is moving NW, or 325 degrees at 08 kt. The estimated minimal central pressure is 990 mb. Maximum sustained winds are 50 kt with gusts to 60 kt. Scattered moderate to strong convection is currently observed within 180 nm of the center. This convection is resulting in very heavy rainfall creating the potential for life-threatening flash floods and mudslides. Combined seas of 9 to 21 ft are forecast S of 27N across the Gulf of California. Lidia will move roughly parallel to the Baja Peninsula and gradually weaken through Sun, then become a remnant low N of 29N. Please see the latest NHC forecast/advisory under AWIPS/WMO headers MIATCMEP4/WTPZ24 KNHC for more details, and for the Public Advisory please see the latest NHC forecast/advisory under AWIPS/WMO headers MIATCPEP4/WTPZ34 KNHC. ...TROPICAL WAVES AND TROPICAL LOWS... A tropical wave is analyzed to the N of 04.5N along 84W, and has been moving W at 12 kt across the W Caribbean. Scattered moderate convection is observed over the EPAC within 75 nm of the wave axis. A tropical wave is analyzed to the N of 06N along 99.5W with a 1010 mb surface low along the wave axis at 11N99W. The system has been moving W at 12 kt over the past 24 hours. Scattered moderate isolated strong convection is observed in an arc within 75 nm either side of a line from 10N103W to 13.5N98W to 11N89W. A 1010 mb surface low is embedded in the monsoon trough at 11.5N136W, with scattered moderate isolated strong convection currently noted within 75 nm E of the low center. ..INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends W across Panama, the Gulf of Panama, and across central Costa Rica through a tropical wave 09N84W to a 1010 mb surface low along a tropical wave at 11N99W to 15N107W where the monsoon trough loses identity in the broad cyclonic circulation associated with T.S. Lidia. Scatterometer winds indicate that the monsoon trough resumes at 18N118W and extends SW through a 1010 mb surface low at 11.5N136W to beyond 11.5N140W. Scattered moderate isolated strong convection is noted within 75 nm either side of a line from 20N105W to 12N120W to 13N126W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Refer to the special features paragraph for information on Tropical Storm Lidia. A ridge will build E along 23N on Sun in the wake of Lidia, with moderate to locally fresh NW breeze setting up across the open waters W of the Baja California Peninsula, as well as across the Gulf of California through early Mon. Gulf of Tehuantepec: light offshore nocturnal flow expected tonight, then moderate drainage flow forecast on Sat, Sun and Mon nights. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo: Gentle to locally moderate offshore nocturnal flow expected tonight and on Sat night, with a moderate to fresh E breeze forecast on Sun night. Otherwise, light and variable flow is expected N of the monsoon trough through early next week, while moderate to locally fresh southerly winds expected S of the monsoon trough axis. REMAINDER OF THE AREA... A ridge extends from 32N140W to near 15N127W, and is accompanied by moderate anticyclonic winds and 5 to 7 ft seas. Fresh southerly monsoonal winds, and seas of 5 to 8 ft are observed S of 15N between 100W and 130W primarily in cross-equatorial swell the will begin to subside late in the upcoming weekend. $$ Nelson