000 AXPZ20 KNHC 151548 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Thu Aug 15 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. ..TROPICAL WAVES AND TROPICAL LOWS... A tropical wave is analyzed FROM 07N98W TO 16N97W and has been moving W at 15 kt. Scattered moderate and isolated strong convection is observed from 06N to 18N between 91W and 100W. A surface low is analyzed at 11.5N104W and is estimated at 1010 MB. The low developed along a tropical wave that is no longer evident. Scattered moderate and isolated strong convection is observed within 240 nm over the NE semicircle of the low. A 1009 mb surface low is analyzed within the monsoon trough at 16N113W. Fresh to locally strong SW to W winds are observed within 150 nm S of a line from 15N114W to 14N124W. Scattered moderate and isolated strong convection is observed within 120 nm either side of a line from 12N113W to 16N117W. The low is forecast to reach near 17N116W early Wed and near 17N120W early Thu with fresh to locally strong NE-E winds expected out 180 nm over the NE semicircle during the next 48 hours, while the winds S of the low will diminish to a moderate to locally fresh breeze. The remnants of former tropical cyclone Jova are analyzed at 20N126.5W. The low lacks convection, however the pressure gradient is supporting strong N to NE winds within 150 nm over the NW quadrant of the low. The low is forecast near 19N131W early Wed, and forecast to weaken to an open trough late Wed with winds diminishing to 20 kt or less and seas subsiding to less than 8 ft by then. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends W across the SW Caribbean along 10N to the Pacific coast of Costa Rica at 09N84W, then continues W- NW through the surface low at 11.5N104W, then turns NW through the second low at 16N113W to 19N123W where it loses identity in the cyclonic circulation associated with the Jova remnant low at 20N126.5W. Scatterometer wind indicate that the monsoon trough resumes near 13N127W, and extends WSW to beyond 12N140W. Except as described above, scattered strong convection is observed is observed S of the monsoon trough, generally to the N of a line from 04N77W to 06N86W. Scattered moderate isolated strong convection is noted within 45 nm of 07N108W, and within 120 nm either side of a line from 13N120W to 11N140W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A NW to SE orientated low level trough will meander E to W across the Baja California Peninsula and Gulf of California through Sat night with a surface low developing intermittently along the trough over the far northern Gulf of California waters. A NW to SE orientated ridge extends across the offshore waters from 25N118W to 21N110W. A gentle NW breeze is expected through Thu to the W of the Baja California Peninsula, except a moderate NW breeze forecast within 90 nm of the Baja coast, with combined seas of 3-5 ft. Guidance is suggesting that the pressure gradient will tighten some Thu night with moderate NW flow W of Baja, except fresh NW flow within 90 nm of the Baja coast. Seas will build to 4 to 6 ft. Gulf of California...gentle to locally moderate southerly flow will persist across the Gulf of California through the upcoming weekend, except a moderate to locally fresh breeze will surround the low pressure center over the waters N of 30N. Gulf of Tehuantepec: light N drainage flow forecast tonight, then fresh N winds on Fri night, and fresh to locally strong northerly drainage winds forecast on Thu, Sat and Sun nights with seas building to 7 ft. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo: moderate to locally fresh offshore winds expected tonight and on Thu night, then gentle to moderate flow thereafter. Gentle NE to E flow expected N of the monsoon trough, while moderate southerly winds are expected S of the monsoon trough axis through the upcoming weekend with 3 to 6 ft seas throughout. REMAINDER OF THE AREA... The subtropical ridge extends from 32N135W to near 25N118W. Except as previously mentioned in the tropical waves and tropical lows paragraph, moderate anticyclonic flow is forecast N of the monsoon trough and W of 125W. Long period southerly swell, in the form of 6 to 8 ft seas, is observed S of a line from 04N81W to 08N100W to 01S102W. These seas will subside to less than 8 ft by midday on Thu. $$ Nelson