000 AXPZ20 KNHC 130333 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 UTC Tue Sep 13 2016 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 0230 UTC. ...SPECIAL FEATURES... At 0300 UTC...Hurricane Orlene was centered at 18.7N 119.1W, or about 660 nm sw of the southern tip of the Baja California Peninsula, and is moving n, or 360 deg, at 05 kt. The estimated minimum central pressure is 971 mb. The maximum sustained winds are 90 kt, with gusts to 110 kt. Numerous strong convection is currently observed within 120 nm of Orlene, surrounded by scattered moderate isolated strong out to 240 nm from the center. Orlene is forecast to gradually weaken. Refer to the latest NHC forecast advisory at WMO/AWIPS headers WTPZ21 KMIA/MIATCMEP1 for additional details. ...TROPICAL WAVES... A tropical wave is analyzed n of 10N along 89W, and will continue w along the Pacific coast of El Salvador and Guatemala tonight accompanied by isolated showers and tstms within 180 nm w of the wave axis. A tropical wave extends n from 07N102W to 15N102W, and has been moving w at 10 to 15 kt. Isolated moderate to strong convection is noted within 120 nm either side of a line from 08N98W to 13N103W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends nw along the Pacific coast of Nicaragua and El Salvador to the Pacific coast of Mexico at 16N94W, then dips sw to a 1011 mb low pressure embedded in the trough at 12N107W to 13N112W where it loses identity. Scatterometer winds indicate that a surface trough forms near 14N124W and extends wsw to beyond 10N140W. Except as previously described near the tropical waves along 89W and 102W, scattered moderate isolated strong convection is observed n of 07N e of 85W to include the Gulf of Panama. Similar convection is observed between the tropical waves roughly within 90 nm either side of a line from 09N91W to 08N98W, within 300 nm over the w semicircle of the low at 12N107W, within 90 nm either side of a line 10N131W to 07N140W and within 30 nm either side of a line from 12N125W to 15N134W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A sub-tropical ridge axis extends from nw to se across the western portion of the offshore zones w of the Baja Peninsula. Moderate to occasionally fresh nw flow expected along the northern portion of the Baja Peninsula through Thu, then gentle to moderate flow expected through Sat. Gentle to moderate nw flow is expected through Sat across the waters s of 30N w of the Baja Peninsula. A thermal trough will meander over the Baja Peninsula and across the northern Gulf of California through the period. This will maintain light, mostly southerly, flow across the Gulf of California for the next few days. The exception is that moderate to fresh s to sw flow will develop across the northern gulf waters between 30N and 31N late tonight, and then persist through early Tue evening. The surface winds will clock to the nw across the entire Gulf of California on Wed and continue through Sat. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Light to gentle winds are forecast to the n of about 09N through Tue and s of 07N on Wed through Sat, while moderate sw to w low level flow is expected across the discussion waters generally to the s of these positions. Forecast combined seas of 4 to 6 ft across the entire area through the period primarily in mixing long-period sw and swell. REMAINDER OF THE AREA... Except as previously mentioned in the special features section concerning TS Orlene, a sub-tropical ridge is rebuilding from w to e across the northern waters. $$ Nelson