Pacific Discussion

  • NHC East Pacific Tropical Weather Discussion
    by nhcwebmaster@noaa.gov (nhcwebmaster) on June 20, 2021 at 7:24 PM

    000 AXPZ20 KNHC 201923 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 UTC Sun Jun 20 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 1800 UTC surface analysis and satellite imagery through 1900 UTC. ...TROPICAL WAVES... The axis of a tropical wave is near 93W north of 05N, moving west at 15 kt. Scattered moderate isolated strong convection is 08N to 15N between 90W and 100W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 09N76W to 11N109W to 10N133W. ITCZ extends from 10N133W to beyond 09N140W. Scattered moderate to isolated strong convection is noted from 03N to 10N E of 88W, and from 06N to 09N between 126W and 140W. Scattered moderate convection is noted within 60 nm N and 180 nm S of trough axis between 102W and 120W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A weak pressure gradient prevails across the Baja waters with gentle to moderate northwest winds over the forecast waters. Wave heights remain in the 5-7 ft range. A surface ridge will build modestly across the area into Mon. Mainly gentle to moderate northwest to north winds will prevail into Tue. In the Gulf of California, fresh to locally strong SE winds are occurring. These will prevail through tonight before diminishing. Wave heights are 4 to 6 ft. Looking ahead, low pressure may develop south of the Gulf of Tehuantepec late this week, and some gradual development is possible while it moves WNW parallel and offshore southern Mexico. 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 SW to W winds are expected across the entire forecast area through Wed, then the pressure gradient will gradually relax with a gentle SW breeze continuing through Sat night. Long period S swell in the form of 5 to 8 ft seas currently across the area will subside through the day, with seas less than 8 ft everywhere by Wed afternoon. Looking ahead, low pressure may develop south of Guatemala late this week, and some gradual development is possible as the system moves WNW. REMAINDER OF THE AREA... A high pressure ridge is across the waters is centered on a 1029 mb high near 40N142W. The pressure gradient between this area of high pressure and lower pressure within the monsoon trough is supporting gentle to moderate winds north of the monsoon trough to near 20N and west of 122W. A tighter pressure gradient between the surface ridge and the trough remnants is supporting fresh northerly winds north of 27N and west of the trough, with seas in the 8-10 ft range. Gentle to moderate SW winds prevail south of the monsoon trough. Southerly swell has propagated northward across the equatorial waters and has reached near 14N today. This swell will continue to spread north-northeastward into tonight, reaching as far as 17N. Wave heights generated by this swell are expected to be in the 7-9 ft range before starting to subside early in the week. $$ KONARIK