000 AXPZ20 KNHC 212148 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 UTC Sun Aug 21 2016 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 1800 UTC surface analysis and satellite imagery through 2130 UTC. ...SPECIAL FEATURES... Tropical Storm Kay is centered near 21.5N 115.3W at 21/2100 UTC or about 282 nm west-southwest of the southern tip of southern tip of Baja California moving west-northwest, or 300 degrees at 7 kt. The estimated minimum central pressure is 1000 mb, with maximum sustained wind speeds of 45 knots with gusts to 55 kt. The 1658Z ASCAT pass from this afternoon clearly showed maximum winds of 45 kt with Kay. Latest Satellite imagery shows a flare up of deep convection over and near the center of Kay in a very symmetrical pattern indicative of a central dense overcast (CDO) feature. The observed convection consists of numerous strong within 45 nm of the center in southwest quadrant. Scattered moderate convection is elsewhere within 120 nm of the center in the southwest quadrant, and also within 30 nm of 23N114W. Kay is forecast to maintain intensity through late tonight as it approaches near 21.9N 116.2W, then begin to gradually weaken over the next couple of days as it encounters less conducive atmospheric conditions. It is forecast to become a remnant low by Tuesday morning and dissipate on Wednesday. Please read the latest NHC forecast/advisory under AWIPS/WMO headers MIATCMEP2/WTPZ22 KNHC for more details, and the latest public advisory MIATCPEP2/ WTPZ32 KNHC, for more details. ...TROPICAL WAVES... Tropical wave axis along 94W from 06N to 15N. Scattered moderate isolated strong convection was noted from 10N to 15N between 91W and 96W. The axis of a tropical wave is along 111W from 05N to 15N. Scattered moderate convection was noted from 08N to 11N between 110W and 114W. The next tropical wave is forecast to reach the central portions of Honduras and Nicaragua and to northern Costa Rica on Tuesday. Expect increasing showers and thunderstorms in those areas with the wave. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from 10N85W to 09N94W to 10N104W to 08N112W to 08N121W. Scattered strong convection is within 120 nm south of the axis between 106W and 109W, and within 60 nm north of the axis between 110W and 111W. Scattered moderate to isolated strong convection is within 180 nm s of the axis between 86W and 90W. Scattered moderate convection is within 120 nm south of the axis between 93W and 99W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Tropical Storm Kay continues to impact the waters to west- southwest of the southern tip of Baja California. Light to moderate winds prevail outside of Kay in a relatively weak pressure pattern, which will persist into early next week. Combined seas of 4 to 7 feet outside of Kay will subside gradually early next week. Scattered showers and thunderstorms have recently developed just inland the east side of far southern Baja California. Similar activity is just along the coasts of Manzanillo and Cabo Corrientes. Expect for this activity to increase further during the rest of the afternoon, and into the evening hours. The activity along the coasts of Manzanillo and Cabo Corrientes is being steered to the southwest under a strong upper level north- northeast wind flow. The Gulf of Tehuantepec: northerly offshore winds will continue to pulse to fresh levels during the late night and early morning hours with nocturnal drainage flow. Northerly flow may increase further to fresh to strong beginning on Tuesday night as high pressure builds over the Gulf of Mexico, and tightens the pressure gradient between the Gulf of Mexico and the monsoon trough over the eastern north Pacific. Wavewatch guidance projects that seas will build to 6 to 7 ft in the Gulf with the fresh to strong northerly flow. Seas may possibly reach 8 ft if duration of these winds is longer than anticipated. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Offshore winds will pulse to moderate to fresh through the Gulf of Papagayo and vicinity today and on Monday, with locally strong winds possible early Tuesday as the southern portion of the next tropical wave to enter the far eastern part of the area passes through the areas of southern Honduras and northern Costa Rica further enhancing the gradient there. Light to moderate winds will prevail on either side of the monsoon trough. Combined seas of 4 to 7 feet will slowly subside through Monday as long period south-southwest swell decays. Seas are expected to be about 5 to 6 ft downstream of the Gulf of Papagayo through Monday, then build to 6 to 8 ft Tuesday. ELSEWHERE... The surface analysis reveals a weak pressure pattern with a 1017 mb high centered at 28N128W. The resulting weak pressure gradient is maintaining generally light to gentle winds with seas in the 4 to 6 ft range. These general conditions will prevail into Tuesday. Cross-equatorial southerly swell with combined seas to 8 ft is forecast to propagate into the far southern waters beginning late tonight with the northern edge of the swell train reaching to near 08N between 109W and 119W on Tuesday. $$ Aguirre