000 AXPZ20 KNHC 130338 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 UTC Sun Aug 13 2023 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 0000 UTC surface analysis and satellite imagery through 0330 UTC. ...SPECIAL FEATURES... Recently upgraded Tropical Storm Fernanda is centered near near 15.0N 114.0W at 13/0300 UTC, moving west-northwest at 9 kt. Estimated minimum central pressure is 1004 mb. Maximum sustained wind speed is 40 kt with gusts to 50 kt. Peak seas are currently to 13 ft. Satellite imagery shows that banding features have become better defined during the past several hours. One noticeable wide convective band wraps about half way around the center of the cyclone. It consists of numerous moderate to strong convection within 30 nm either side of a line from 18N114W to 16N116W to 14N116W. In addition, numerous moderate to isolated strong convection is seen from 13N to 16N between 112W-116W. Numerous moderate convection is from 11N to 13N between 111W-117W. Fernanda is forecast to maintain its current motion through the next few days at slightly slower forward speed. Steady to rapid strengthening is forecast during the next day or two, and the system is expected to become a hurricane by early Sun evening near 15.7N 116.9W with maximum sustained speed 65 kt gusts to 80 kt. Peak seas at that time expected to be at about 27 ft. Please read the latest HIGH SEAS FORECAST issued by the National Hurricane Center at website - https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml and the latest Seven-E NHC Forecast/Advisory and Public Advisory at www.hurricanes.gov for more details. Western East Pacific Invest (EP99): A broad area of low pressure associated with a tropical wave is producing a large area of disorganized scattered moderate to isolated strong convection from 11N to 13N between 134W-138W well to the east-southeast of the Hawaiian Islands. Scattered moderate convection is within 30 nm of 08N133W. Conditions appear conducive for development of this system, and a tropical depression is likely to form during the next few days while moving toward the west or west-northwest across the far western portion of the basin, crossing into the Central Pacific basin Sun night. Please refer to the latest NHC Tropical Weather Outlook at www.hurricanes.gov for more details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from northwest Colombia to central Panama and continues to 09N79W to 08N91W to 10N100W to 12N108W, where it pauses. It resumes from near 11N120W to low pressure near 10N134W 1010 mb. The ITCZ extends from the low pressure to beyond 08N140W. Numerous moderate to strong convection is seen from 04N to 09N between 87W-95W. Scattered moderate convection is within 180 nm south of the trough between 102W-108W, also within 120 nm south of the ITCZ between 135W-140W and within 60 nm south of the trough between 77W-81W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A surface ridge dominates the offshore forecast waters of Baja California producing gentle to moderate NW to N winds along with seas of 4-6 ft. Inside the Gulf of California, gentle to moderate southeast winds are south of 30N, while moderate S to SW winds prevail across northern part of the Gulf. Seas are generally 1-3 ft over the Gulf, except for slightly higher seas of 3-4 ft near the entrance. For the forecast moderate to fresh NW winds are expected offshore the coast of Baja California from Punta Eugenia to Cabo San Lazaro mainly at night through early next week. Fresh to strong north gap winds are forecast to pulse in the Tehuantepec region Sun through Tue, and may increase to fresh to strong speeds toward the end of the forecast period as a tropical depression is expected to form from a large area of disturbed weather over the eastern Pacific during the early or middle part of next week. The depression is expected to move generally west- northwestward, roughly parallel to the coast of southern and southwestern Mexico. ...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Moderate to fresh northeast to east winds are across the Gulf of Papagayo region reaching westward to near 90W. Light to gentle westerly winds are elsewhere north of 05N, and mainly moderate south to southwest winds between the Equator and 05N. Gentle to moderate southerly winds dominate the waters between Ecuador and the Galapagos Islands. Seas are generally 3-5 ft due to long- period south to southwest swell, except 1-3 ft in the Gulf of Panama, and 3-5 ft offshore Colombia. For the forecast, offshore winds will pulse to moderate to fresh at night into the early morning hours in the Papagayo region through early next week. Elsewhere, gentle to moderate winds and moderate seas will prevail through Sun night. Looking ahead, a tropical wave currently over Central America and the far eastern Pacific is producing a large area of disturbed weather. Environmental conditions are anticipated to be conducive for development of this system, and a tropical depression is expected to form during the early or middle part of next week while it moves generally west-northwestward, roughly parallel to the coast of southern and southwestern Mexico. Expect increasing winds, seas, and unsettled weather during this time, mainly across the outer offshore waters from northern Costa Rica to Guatemala. ...REMAINDER OF THE AREA... Please refer to the section above for details on recently upgraded Tropical Storm Fernanda and on Invest EP99. Outside of the systems mentioned above, a weak pressure gradient remains west about 110W. A surface ridge remains in control of the weather conditions across the region. Gentle to moderate winds and moderate seas prevail under the influence of the ridge. For the forecast, Tropical Storm Fernanda is forecast to strengthen to hurricane intensity by early Sun evening near 15.7N 116.9W with a maximum sustained winds of 65 kt with gusts to 80 kt. It is forecast to intensify further as it reaches near 16.0N 118.3W by early on Mon with maximum sustained winds 80 kt with gusts to 100 kt and maintain this intensity through early Tue. Elsewhere, fairly tranquil conditions are forecast across the open waters through the upcoming week as a weak pressure pattern dominates the region. $$ Aguirre