000 AXPZ20 KNHC 272150 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 UTC Sun Aug 27 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 1800 UTC surface analysis and satellite imagery through 2145 UTC. ..TROPICAL WAVES AND TROPICAL LOWS... A tropical low pressure is analyzed at 08N86W and is estimated at 1009 mb. Currently scattered moderate isolated strong convection is observed within 360 nm over the w semicircle of the low. A tropical wave is analyzed to the N of 06N along 101.5W and has moved W at 12 kt over the past 24 hours. Scattered moderate isolated strong convection is observed to the S of 16N within 300 nm E and within 390 nm W of the wave axis. A tropical wave is analyzed from 10.5N114W TO 21N113W... scattered moderate isolated strong convection is noted to the S of 16N within 300 nm E and within 180 nm W of the wave axis. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends W across the far SW Caribbean along 09.5N and continues W to the Pacific Coast of Costa Rica at 10N83W, then turns SW through an embedded 1009 mb surface low at 08N86W, then the monsoon trough turns abruptly NW to a tropical wave at 16N101W, then turns W through another tropical wave at 15N114W, then wiggles WSW to beyond 10N140W. Scattered moderate isolated strong convection is observed S of the monsoon trough within 180 nm of 07N82W, and elsewhere within 90 nm either side of a line from 12N121W to 10N140W. ...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 this evening. A NW to SE orientated ridge extends across EPAC waters well beyond 250 nm. The resultant pressure gradient will support a moderate NW breeze across the open waters W of the Baja California Peninsula, except increasing to a fresh NW breeze on Mon evening behind a weak cold front within about 90 nm of the Pacific Coast of Baja California. The weak cold front is forecast to stall and wash out along 28N late Mon night through midday on Tue. Expect a brief moderate SW-W-NW wind shift near the front across the Gulf of California, otherwise light and variable flow expected through Wed morning. The leading edge of fresh to locally strong southwesterly monsoon flow, and long period cross-equatorial swell, in the form 7 to 10 ft seas, has reached along 15N across the waters 250 nm seaward between 100W and 110W. A tropical low is forecast to develop near 16N108W on Mon and track N between 107W and 112W early in the week with favorable environmental conditions for tropical cyclone formation. A band of fresh to locally strong southerly flow is forecast to develop within about 300 nm E of the low, and these conditions will shift N and W across the Mexican offshore waters between about 103W and 115W this week, with winds increasing to at least near gale force. The current forecast is for strong SE flow, and 6 to 8 ft seas, and significant convection, to spread N across the southern Gulf of California beginning late Wed night, with near gale conditions across the southern Gulf waters on Fri morning as the low center then tracks NW across the offshore waters W of Baja. Plenty of uncertainty in this scenario, and changes to track and intensity are very likely. Gulf of Tehuantepec: light offshore nocturnal flow expected this week, with light to gentle onshore flow during the day. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo: Moderate ENE flow forecast through midday Mon. Otherwise, light and variable flow is expected N of the monsoon trough through the middle of next week, while moderate to locally fresh southerly winds are expected S of the monsoon trough axis. Long period southerly cross-equatorial swell, in the form of 7 to 9 ft seas is currently along 03N, and will continue to propagate N reaching along 06N by early Mon, then subside Mon night with seas forecast to less than 8 ft on Tue. REMAINDER OF THE AREA... The remnant low of former tropical cyclone Kenneth continues to spin near 29N136W. The estimated minimum central pressure is 1017 mb. A recent scatterometer pass detected a fresh NE-E winds along 31.5N. This low should finally weaken to an open trough tonight. A ridge extends from 32N129W to near 19N111W, and is accompanied by moderate anticyclonic winds and 4 to 6 ft seas. Fresh to locally strong southerly monsoonal winds and seas of 7 to 10 ft are observed from 04N to 14N between 100W and 130W. These conditions will continue this week as a surface low previously described develops near 16N108W. $$ Nelson