000 AXPZ20 KNHC 190927 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Sat Jun 19 2021 Tropical Weather Discussion for the eastern Pacific Ocean from 03.4S to 30N, east of 120W including the Gulf of California, and from the Equator to 30N, between 120W and 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 0850 UTC. ...SPECIAL FEATURES... Tropical Storm Dolores is centered near 17.0N 103.1W 995 mb at 0900 UTC moving NNW or 330 DEG at 9 KT. Maximum sustained winds are 50 KT gusts to 60 KT. Scattered to numerous moderate to scattered strong convection is noted within 180 nm of the center with a recent large cluster of strong convection across the S semicircle. Dolores will track north-northwestward today and could intensify to just below hurricane strength this afternoon just before reaching the coast near 18.6N 103.6W, then move inland across SW Mexico tonight and quickly begin weakening near 21.4N 104.4W. Heavy rains are forecast over coastal sections of the Mexican states of Guerrero, Michoacan, Colima, Jalisco, and Nayarit through the weekend, where rain accumulations of 6 to 10 inches are expected. This could result in life- threatening flash flooding and mudslides. Please see the latest NHC Public Advisory at https://www.nhc.noaa.gov/text/MIATCPEP4.shtml and Forecast/ Advisory at https://www.nhc.noaa.gov/text/MIATCMEP4.shtml for more details. ...TROPICAL WAVES... The axis of a tropical wave is near 89W north of 02N, moving west at 10 to 15 kt. Scattered moderate isolated strong convection is noted N of 10N between 87W and 91W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 10N75W to 08N81W to 15N99W, then resumes SW of Dolores near 13N105W to 08N133W to 10N140W. Scattered moderate to strong convection is noted from 02N to 06N E of 79.5W, and from 04.5N northward to the coasts between 84W and 100W. Scattered moderate isolated strong convection is noted within 90 nm S of the trough between 105W and 123W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see the Special Features section above for information on Tropical Storm Dolores. Elsewhere, a high pressure ridge across the NE Pacific is being prevented from extending into the waters west of Baja California Norte by a surface trough just west of 120W. This is yielding a weak pressure gradient across the waters and gentle to moderate northwest winds over the forecast waters. Wave heights remain in the 5-7 ft range. A surface ridge will building across the area this weekend as the trough dissipates. Mainly gentle to moderate northwest to north winds will prevail into Tue. In the Gulf of California, gentle to moderate winds will continue along with wave heights of 3 ft or less through Saturday. Winds are forecast to increase across the north and central parts of the Gulf on Sun and into early next week as the pressure gradient tightens between the ridge west of Baja California peninsula and low pressure over north-central Mexico. Wave heights are expected to build to 4-5 ft across north and central portions with these winds. Winds and seas are expected decrease by Tuesday. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, and WITHIN 750 NM OF ECUADOR... Gentle to moderate SW to W winds prevail south of the monsoon trough, with light to gentle NE winds north of 10N and the monsoon trough. Seas are in the 5-7 ft range in SW swell. Gentle to moderate southwest to west winds will continue over the offshore waters S of 10N, with variable winds north of 10N. Moderate to fresh winds will pulse in the Gulf of Papagayo tonight and Sat night. New SW swell has crossed the equatorial waters overnight and will reach the offshore waters tonight through Sun to raise seas to 6-8 ft, and continue into early next week. REMAINDER OF THE AREA... A surface trough extends from offshore of southern California to near 25N127W. A 1030 mb high pressure is centered across the waters west of this trough near 39N140W. The pressure gradient between this area of high pressure and lower pressure within the monsoon trough is only supporting gentle to moderate winds north of the monsoon trough to near 15N and west of 120W. A tighter pressure gradient between the surface ridge and the trough is supporting fresh to strong northerly winds north of 28N and west of 125W, with seas in the 8-10 ft range. Gentle to moderate SW winds prevail south of the monsoon trough. Southerly swell has propagated across the waters along the equator. This swell will continue to spread north-northeastward into the weekend reaching as far as 17N this weekend. Wave heights generated by this swell are expected to be in the 7-9 ft range before starting to subside early next week. $$ Stripling