262 AXPZ20 KNHC 180325 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 UTC Fri Aug 18 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 0300 UTC. ...SPECIAL FEATURES... Hurricane Hilary is centered near 16.7N 110.0W at 18/0300 UTC, moving west-northwest at 12 kt. Estimated minimum central pressure is 952 mb. Maximum sustained wind speed is 110 kt with gusts to 130 kt. Hilary continues to rapidly intensify. The presentation on infrared satellite imagery has become very impressive. Numerous moderate to strong convection is present within 75 nm N and 90 nm S semicircles. A well defined outer rain band of about 60 nm wide is to the E of the center and extends 17N107W to 13N112W. The 12 ft seas radii continues to expand as Hilary intensifies. It extends outward within 300 nm E and 180 nm W semicircles with maximum seas of 40 ft. in the NE quadrant, 330 nm in the SE quadrant and 180 nm in the W semicircle. Meanwhile, the elsewhere 8 to 12 ft seas cover the area roughly from 06N to 23N between 98W-114W. On the forecast track, A turn toward the northwest is expected to begin tomorrow morning, followed by a turn toward the north-northwest and north on Saturday. The center of Hilary will approach the Baja California peninsula over the weekend. Hilary is a category 3 hurricane on the Saffir-Simpson Hurricane Wind Scale. Rapid intensification is expected to continue through tomorrow morning, and Hilary is likely to become a category 4 hurricane. Hilary should then begin to weaken on Saturday. A storm surge could produce coastal flooding along the western Baja California peninsula of Mexico near where the center passes the coast in areas of onshore winds, or east of the center if Hilary makes landfall. The surge will be accompanied by large and destructive waves. Large swells generated by Hilary will affect portions of the coast of southwestern Mexico and the Baja California peninsula over the next few days. These swells are likely to cause life-threatening surf and rip current conditions. Please consult products from your local weather office. Interests elsewhere on the Baja California peninsula and along the coast of northwestern mainland Mexico and the southwestern United States coastline should closely monitor the progress of Hilary. 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 Hilary NHC Forecast/Advisory and Public Advisory at www.hurricanes.gov for more details. ...TROPICAL WAVES... A tropical wave is along 93W/94W from 04N northward to across SE Mexico. It is moving westward around 10 kt. Scattered moderate to isolated strong convection is from 03N to 09N between 89W and 97W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from southern Costa Rica near 09N83W to 08N90W to 11N100. It resumes SW of Hurricane Hilary from near 12N113W to 09N130W. The ITCZ extends from 09N130W to beyond 07N140W. Scattered moderate to isolated strong convection is seen from 08N to 11N between 110W and 120W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO...Corrected Please see the Special Features section for information on Hurricane Hilary that is approaching major hurricane status. Outside of Hurricane Hilary, generally weak high pressure is present over the offshore forecast waters of Baja California. The associated gradient is allowing for moderate to locally fresh NW to N of Cabo San Lazaro, with gentle to moderate winds elsewhere in the Baja California offshore waters. Seas are 4-6 ft. In the Gulf of California, light to gentle winds are noted along with seas of 1-2 ft, except seas of 3-4 ft near the entrance to the Gulf. Pulses of moderate to fresh north winds and seas to about 7 ft are in the Tehuantepec region. For the forecast, Hilary will move to 17.7N 111.4W Fri morning, 19.4N 112.6W Fri evening, 21.5N 113.6W Sat morning, 24.0N 114.3W Sat evening, 27.2N 115.0W Sun morning, and weaken to a tropical storm near 30.7N 116.1W Sun evening. Hilary will weaken to a remnant low near 39.0N 118.3W late Mon. Very high seas are expected in the northern Gulf of California Sun and Sun night. The pulses of moderate to fresh north winds in the Gulf of Tehuantepec are forecast to become more persistently at fresh to strong speeds beginning on Sun afternoon. Looking ahead, a A broad area of low pressure could form offshore of the coast of southern Mexico during the early or middle part of next week. Some gradual development of this system is possible thereafter while it moves slowly west-northwestward or northwestward. This system has a low chance of tropical cyclone development over the next 48 hours and 7 days. ...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Moderate to fresh northeast to east winds are in the Papagayo region and downwind to about 89W. Seas are 5-7 ft with these winds. Gentle to moderate winds and seas in the 4 to 6 ft range prevail elsewhere across the Central and South America forecast waters, with the exception of 1-3 ft seas in the Gulf of Panama, and 3-4 ft just offshore Colombia. For the forecast, fresh to strong northeast to east winds will pulse in the Gulf of Papagayo region at night and into the mornings through Fri night, then to fresh speeds through early next week. Elsewhere gentle to moderate winds and moderate seas are expected through the upcoming weekend. ...REMAINDER OF THE AREA... The remnant low of former tropical cyclone Fernanda is near 16N134W with a pressure of 1005 mb. Fresh to strong winds are within 180 nm N and 60 nm S semicircle of center with seas of 9-13 ft. A small cluster of moderate convection is WSW of the remnant low near 15.5N135.5W. Seas of 8 to 9 ft are observed elsewhere from 13N to 20N between 131W and 137W. This system is forecast to cross 140W by Fri night. A ridge dominates most of the waters N of 20N and W of 120W. The pressure gradient between the ridge and the remnant low pressure supports an area of moderate to fresh winds from 18N to 23N between 125W and 138W. Light to gentle winds are noted elsewhere under the influence of the ridge. Moderate to fresh winds are south of the monsoon trough roughly between 100W-130W. Elsewehre, seas are 4 to 7 ft primarily in mixed swell north of 15N and west of 118W and in south to southwest swell mixed with northeast swell elsewhere. $$ GR