000 AXPZ20 KNHC 111500 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1406 UTC Sun Sep 11 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 1200 UTC surface analysis and satellite imagery through 1500 UTC. ...SPECIAL FEATURES... At 1500 UTC, Tropical Storm Orlene was centered near 15.4N 116.8W moving northwest, or 305 degrees, at 12 kt. Estimated minimum central pressure was 1005 mb. Maximum sustained wind speeds were 40 kt with gusts to 50 kt. Numerous moderate and scattered strong convection was noted within 120 nm of the center. Orlene is forecast to move to the west- northwest while intensifying to a minimal hurricane by Monday afternoon, with a significant decrease in forward speed through the early part of the week. See latest NHC forecast/advisory under AWIPS/WMO headers MIATCMEP1/WTPZ21 KNHC for more details. ...TROPICAL WAVES... The axis of a tropical wave extends from the far southwest Gulf of Mexico southward across southeast Mexico to near 05N97W. Scattered moderate and isolated strong convection associated to this wave was noted from 06N to 15N between 94W and 99W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 08N83W to 11N96W to 11N107W. Scattered moderate isolated strong convection was noted from 02N to 07N east of 81W. Scattered moderate isolated strong convection was noted within 60 nm either side of the monsoon trough between 84W and 88W. Scattered moderate isolated strong convection was noted within 120 nm north and 30 nm south of the monsoon trough between 103W and 106W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A sub-tropical ridge axis extends from northwest to southeast across the western portion of the offshore zones west of the Baja Peninsula. This will promote gentle to moderate northwest flow through the period. Moderate to fresh northwest flow will develop along the central Baja Peninsula briefly on Monday evening. 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 much of the Gulf of California. Winds will increase to moderate south to southwest over the northern gulf waters over the far northern waters tonight, with fresh to moderate southerly flow in the same area on Monday night into Tuesday. A fresh to strong northerly surge will develop across, and just downstream of the Gulf of Tehuantepec tonight before diminishing early Monday. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Light to gentle winds will prevail north of 10N through the period with gentle to moderate southwest to west winds flow prevailing to the south of 10N. Combined seas are forecast to be 4 to 7 ft across the entire area through the period, primarily in long- period southwest swell. REMAINDER OF THE AREA... See special features above for more on Orlene. Elsewhere over the forecast waters, weak high pressure of 1021 mb is centered over the northern waters near 27N128W. A weak trough analyzed from 15N to 22N along 131W will continue to drift west across the waters and gradually weaken through Monday. High pressure will further build across the northern waters early this week. $$ AL