000 AXPZ20 KNHC 120318 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 UTC Tue Sep 12 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 0000 UTC surface analysis and satellite imagery through 0200 UTC. ...SPECIAL FEATURES... The center of Tropical Depression FIFTEEN-E at 12/0300 UTC is near 16.2N 113.6W. T.D. FIFTEEN-E is moving W, 260 degrees, 12 knots. The minimum central pressure is 1006 mb. The maximum sustained wind speeds are 25 kt with gusts to 35 kt. The PUBLIC ADVISORIES about T.D. FIFTEEN-E are being issued under the WMO header WTPZ35 KNHC, and under the AWIPS header MIATCPEP5. The FORECAST/ADVISORIES about T.D. FIFTEEN-E are being issued under the WMO header WTPZ25 KNHC, and under the AWIPS header MIATCMEP5. Convective precipitation: SCATTERED MODERATE ISOLATED STRONG WITHIN 240 NM W QUADRANT. A surface trough, that is located a couple of hundred miles south of the southern coast of Mexico continues to produce disorganized showers and thunderstorms. Environmental conditions are forecast to be conducive for development, and a tropical depression is likely to form later this week while the system moves slowly northwestward. The chance of formation is medium. INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... MONSOON TROUGH FROM 15N93W TO 13N108W TO 15N112W TO 15N116W TO LOW PRES NEAR 12N134W 1010 MB...TO 11N140W. SCATTERED MODERATE ISOLATED STRONG WITHIN 360 NM S OF MONSOON TROUGH E OF 117W... AND WITHIN 90 NM N AND 270 NM S OF MONSOON TROUGH BETWEEN 119W AND 133W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... An area of low pressure is expected to form several hundred miles to the south-southwest of the Baja California peninsula in a day or two. Environmental conditions are expected to be conducive for gradual development after that time while it moves slowly northward. The chance of formation is low. A NW to SE oriented trough will meander across the Baja California Peninsula and the Gulf of California with a surface low developing intermittently along the trough axis over the far northern Gulf waters. A W to E orientated ridge will meander from 23N116W to 21N110W early this week with a moderate W to NW breeze is forecast across the EPAC waters S and W of the Baja California Peninsula through Wed afternoon, with 5 to 6 ft seas. Gulf of Tehuantepec: Strong to near gale force northerly flow is expected through early Tue, with seas building to 11 ft downstream of the gulf waters near 14N96W. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... The monsoon trough has lifted N, with moderate to locally fresh southwesterly monsoonal flow expected S of the trough axis expected the next several days. Seas in the 6 to 9 ft range in cross- equatorial southerly swell prevails. These southerly swells will begin to subside on Tue night, with seas expected to fall below 8 ft by Fri night. REMAINDER OF THE AREA... A surface ridge passes through 32N140W to 23N140W. Moderate anticyclonic flow is expected N of the monsoon trough and W of 115W. Fresh to locally strong SW monsoonal flow, and 8 to 12 ft seas, is forecast from 06N to 10N between 97W and 110W today in long period cross- equatorial swell. This swell will begin to subside on Tue night. $$ mt