361 AXPZ20 KNHC 290953 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 952 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 0600 UTC surface analysis and satellite imagery through 0900 UTC. ...SPECIAL FEATURES... Tropical Depression Gilma centered near 16.1N 137.0W at 29/0900 UTC or 1060 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. Numerous moderate to scattered strong convection is observed within 240 nm in the east semicircle of the depression. See latest NHC forecast/advisory under AWIPS/WMO headers MIATCPEP3/WTPZ33 KNHC for more details. ...TROPICAL WAVES... A tropical wave extends north of 10N along 90W. Scattered moderate to isolated strong convection is observed off the Central American coast and near where the tropical wave is interacting with the monsoon trough within 120 nm off the coast between 87W and 97W. A tropical wave extends along 126W from 04N to 15N moving W at 10 to 15 kt. No significant convection is noted. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 10N85W to 11N92W to low pressure near 09N103W to 08N120W. Segments of the intertropical convergence zone axis extend from 08N120W to 10N131W, from 08N125W to 14N133W, and from 13N137W to 11N140W. Scattered moderate and isolated strong convection within 120 nm off the Central American coast between 87W and 97W, 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: Moderate to fresh gap winds will diminish later this morning over the Gulf of Tehuantepec. 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. Convection is pulsing near broad low pressure centered west of the offshore waters of Central America near 09N103W. The estimated sea level pressure is 1010 mb. While there has been steady development of this system over the past 12 to 18 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. At any rate, large clusters of showers and thunderstorms are ongoing within 180 nm mainly in the northwest semicircle of the low pressure. Expect fresh to occasionally strong winds in this convection, with seas building to 8 ft through the next two to three days. 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