612 AXPZ20 KNHC 292103 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2103 UTC Sun Jul 29 2018 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 2100 UTC. ...SPECIAL FEATURES... Post-Tropical Cyclone Gilma centered near 16.2N 139.7W at 29/2100 UTC or 900 nm E of Hilo Hawaii moving W at 13 kt. Estimated minimum central pressure is 1008 mb. Maximum sustained wind speed is 30 kt with gusts to 40 kt. Widely scattered moderate convection is within 420 nm in the east quadrant. See the final NHC forecast/advisory under AWIPS/WMO headers MIATCPEP3/WTPZ33 KNHC for more details. ...TROPICAL WAVES... A tropical wave extends north of 09N along 94W moving west at around 10 kt. Scattered moderate and isolated strong convection is within 300 nm west of the wave axis and also from 10N to 16N between 99W and 103W. A tropical wave extends from 03N to 16N along 129W moving W at 10 to 15 kt. No significant convection is observed. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from northern Colombia near 10N76W to 10N83W to 11N95W to low pressure near 10.5N106W to 08N117W. The intertropical convergence zone axis extends from 08N117W to 09N127W. Scattered moderate and isolated strong convection is within 360 nm south of the monsoon trough east of 89W. Scattered moderate convection is within 150 nm south of the monsoon trough between 107W and 111W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Gulf of Tehuantepec: Moderate northerly nocturnal gap winds will prevail over the Gulf of Tehuantepec, increasing to moderate to fresh Tue night as higher pressure builds north of the area and lower pressure develops to the south. Elsewhere a trough persists from Baja California Norte southeast to 21N109W. This is resulting in a fairly weak pressure pattern across the open offshore waters of Mexico. Scatterometer data show light to gentle NW winds in most areas and 3 to 5 ft seas. An earlier scatterometer pass indicated gentle to moderate SE flow persisting along the length of the Gulf of California. Little change is expected through the week. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo: Moderate easterly flow is expected through the week, occasionally pulsing to fresh. Gentle to occasionally moderate E winds are forecast elsewhere N of the monsoon trough which is meandering between 08N and 10N. Moderate to locally fresh southerly winds are forecast S of the monsoon trough through the week accompanied by 5 to 7 ft seas. REMAINDER OF THE AREA... See the special features section for information on Post-Tropical Cyclone Gilma and the tropical wave beyond the offshore waters areas. Convection is pulsing near broad low pressure centered near 10.5N106W. Scattered moderate and isolated strong convection is within 240 nm in the north quadrant of the low. While there has been steady development of this system over the past 24 hours, there remains some uncertainty about its development over the next couple of days. There is a moderate chance for tropical cyclone development through the next five days. Expect fresh to occasionally strong winds in this convection, with seas building to 8 ft through the next couple of days. Otherwise, ridging will persist north of 20N west of 120W through the week, supporting moderate N to NE winds and 5 to 7 ft seas in that area. Moderate to locally fresh southerly forecast elsewhere S of the monsoon trough or roughly 10N for the next several days. $$ Lewitsky