725 AXPZ20 KNHC 290342 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 342 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 0000 UTC surface analysis and satellite imagery through 0300 UTC. ...SPECIAL FEATURES... Tropical Depression Gilma centered near 16.1N 135.7W at 29/0300 UTC or 1130 nm E of Hilo Hawaii moving WNW at 12 kt. Estimated minimum central pressure is 1008 mb. Maximum sustained wind speed is 30 kt with gusts to 40 kt. Scattered moderate to isolated strong convection is observed within 120 nm in the east quadrant of the center of Gilma. See latest NHC forecast/advisory under AWIPS/WMO headers MIATCPEP3/WTPZ33 KNHC for more details. ...TROPICAL WAVES... A tropical wave has moved off the coast of Nicaragua and is entering the eastern Pacific. It extends north of 10N along 88W. Scattered moderate to isolated strong convection is observed where the tropical wave is interacting with the monsoon trough from 05N to 09N between 88W and 92W. A tropical wave extends along 125W from 04N to 15N moving W at 10 to 15 kt. Associated scattered moderate convection is from 12N to 15N between 124W and 127W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 10N85W to 11N95W to low pressure near 09N102W to 09N120W. Segments of the intertropical convergence zone axis extend from 09N120W to 10N131W, from 08N125W to 14N133W, and from 13N137W to 11N140W. Scattered moderate and isolated strong convection is from from 12N to 15N between 124W and 127W, and within 180 nm in the northwest quadrant of the low pressure near 09N102W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Gulf of Tehuantepec: Northerly gap winds into the Gulf of Tehuantepec will increase to moderate to fresh by late evening. This is due to local drainage effects interacting with a relatively tight pressure gradient between higher pressure over the Gulf of Mexico and lower pressure far south into the tropical Pacific. These gap winds will diminish by mid morning. Weaker gap winds are expected thereafter through early next week due to diminishing high pressure north of the area. Looking ahead, stronger gap winds are likely by mid week as higher pressure builds north of the area and lower pressure develops to the south. Elsewhere a trough persists from Baja California Norte southwest to 20N125W. 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 early next 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 early next week. 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 into early next week accompanied by 5 to 7 ft seas. REMAINDER OF THE AREA... See the special features section for information on Tropical Depression Gilma and the tropical waves section. Otherwise, ridging will persist north of 20N west of 120W through the period, 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. $$ Christensen