000 AXPZ20 KNHC 210138 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0104 UTC Wed Aug 21 2019 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 0100 UTC. ...SPECIAL FEATURES... A low pressure system of 1008 mb is located near 15N103W or about 200 miles south of Michoacan. The large area of showers and thunderstorms associated with this low are beginning to show signs of organization, and environmental conditions are favorable for further development. Currently, numerous moderate and scattered strong convection is located from 10N to 17N between 96W and 110W. A tropical depression is likely to form Wednesday or Thursday as the low moves WNW at 10 to 15 kt, parallel and several hundred miles offshore the coast of central Mexico. This system could still produce locally heavy rainfall and flash flooding over Oaxaca, Guerrero, and Michoacan over the next couple of days. The latest Tropical Weather Outlook gives this low a 90 percent chance of tropical cyclone formation through 48 hours. A recent altimeter pass showed seas of 8 to 9 ft to the south and east of the low's center, and winds and seas are expected to increase through the week near the low. A Gale Warning is in effect for Mexico offshore waters from Acapulco to Sinaloa as well as the waters offshore the southern parts of Baja California Sur. Farther west, another weak low pressure system is located near 16N123W about 1000 miles WSW of the southern tip of the Baja California peninsula and continues to produce disorganized showers and a few thunderstorms, generally from 12N to 17N between 125W and 135W, well west of the center. Environmental conditions no longer appear conducive for development, and there is now only a low chance of tropical cyclone formation in the next several days. This low is expected to move slowly west through the week. Refer to the latest NHC Tropical Weather Outlook under AWIPS/WMO headers MIATWOEP/ABPZ20 KNHC for more information on both of these lows. ...TROPICAL WAVES... A tropical wave axis is located near 90W. Scattered moderate and isolated strong convection is located from 05N to 12N between 80W and 90W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 08N80W to 12N90W to low pressure near 15N103W to 12N110W to 18N120W to low pressure near 16N123W to near 12N135W. Convection in the vicinity of the trough is mainly associated with the aforementioned lows and tropical waves. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see the Special Features section for more details about the low pressure area offshore Guerrero. High pressure well northwest of the area will promote fresh to locally strong NW winds offshore of Baja California Norte through Wed. Low pressure over the U.S. Great Basin will induce fresh to strong SE to S winds over the Gulf of California Thu and Fri. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... A weak pressure gradient is producing only gentle to moderate winds across the region for the next several days. Long-period cross equatorial SW swell will reach the waters between Ecuador and the Galapagos Islands on Wed, building seas to 6 to 7 ft late Wed into Thu. REMAINDER OF THE AREA... Please see the Special Features section for more details about the low pressure area near 16N122W. A 1022 mb high pressure located near 33N128W extends a ridge across the northern forecast waters. This system will remain nearly stationary over the next 48 hours producing mainly gentle to moderate winds N of 20N and W of 110W. The pressure gradient between the ridge and lower pressures in the vicinity of the monsoon trough will result in moderate to fresh trade winds S of 20N. Wind are expected to increase S of the monsoon trough Wed through Thu night, particularly between 105W and 120W. As the monsoon through continues to lift northward as the low pressure located offshore Mexico moves WNW, combined SW swell and wind waves to the south may produce seas of up to 10 ft S of 15N between 100W and 120W Wednesday and Thursday. Some northerly swell will reach south of 30N around 120W Thursday, with some seas of 8 to 9 feet possible. $$ KONARIK