000 AXPZ20 KNHC 252218 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 UTC Thu Oct 25 2018 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 2100 UTC. ...TROPICAL WAVE... A tropical wave is analyzed N of 03N along 99W-100W moving W 8 kt. Isolated clusters of moderate to strong convection are flaring along the monsoon trough near the wave. A 1011 mb surface low has formed during the past 12-18 hours behind the wave, near 08.5N96W, and is moving W 7 kt and expected to follow the wave westward during the next few days. Some modest organization and an increase in winds to 20-25 kt surrounding this low is expected. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 09N75W TO 09N89W TO LOW PRES NEAR 09N96W TO 07N108W TO LOW PRES NEAR 14N119.5W TO LOW PRES NEAR 11N124.5W, where scatterometer winds indicate a transition to an ITCZ, which then continues W to 09.5N132W to beyond 09.5N140W. Scattered moderate convection is observed within 180 nm over the N and 90 nm across the S semicircles of the surface low at 14N119.5W. Scattered moderate to strong convection is observed within 240 nm over the NE and 180 nm across the SW quadrants of the surface low at 11N124.5W. Scattered moderate to strong convection is noted from 05N to 10N between 77W and 84W, and within 150 nm of the ITCZ W of 126W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A modest ridge extending from the waters W of 120W extends SE to near the Islas Revillagigedo this afternoon and will prevail across the offshore waters through the upcoming weekend. This pattern will produce gentle to locally moderate NW to N flow W of the Baja California Peninsula through Fri night, before winds weaken slightly over the weekend. Strong N to NE winds and 8 to 12 ft seas will spread into the waters N of 2N and W of 118W on Sun, with associated NW swell raising seas across the offshore waters of Baja California Norte to 8-9 ft late Mon. Gulf of California: Light and variable winds will become a gentle NW breeze by Fri morning, and a moderate NW breeze on Fri night, with little change then through Sat night. Gulf of Tehuantepec...Gentle onshore flow is forecast during the daylight hours, and gentle to locally moderate offshore drainage expected nocturnally through late Sat. Model guidance suggests the next strong to near gale northerly wind event will begin on Sat evening, with gale force conditions possible on Sun evening through Tue morning with seas building to 14 ft downstream of the gulf waters. Guidance indicates the northerly winds will diminish to 20 kt or less, and seas will subside to less than 8 ft late Wed night. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo...Moderate NE winds prevail across and downstream of the Gulf this afternoon, with little change through Sun, when fresh to strong NE flow is forecast to resume, and then continue through late Mon. Light to gentle variable winds, and 3 to 6 ft seas are forecast elsewhere N of the monsoon trough through early next week, while moderate southwesterly monsoonal flow, with 5 to 7 ft seas, are forecast S of the monsoon trough. REMAINDER OF THE AREA... A 1025 mb surface high meandering over the far NW waters near 31N131W is forecast to shift NE to near 32N133W by early Fri, and lift N of 32N on Fri night. The pressure gradient to the south and along the ITCZ is producing a zone of fresh to strong NE to E tradewinds from 10N to 24N to the W of 124W. Mixing swell will maintain a large area of 7 to 9 ft seas N of the ITCZ and W of 130W through Sat morning. NW swell in the form of 7 to 9 ft seas, will reach along 28N between 122W and 130W on Fri, then subside to less than 8 ft Fri night. A 1009 mb low near 14N119.5W along the monsoon trough will move WSW for the next few days, and pass south of the ridge to produce a small area of 20-25 kt NE winds across the NW quadrant of the low, where seas will remain around 8 ft. The low will likely dissipate over the weekend. A 1011 mb surface low analyzed along the monsoon trough at 11N124.5W is expected to also move WSW and lose identity within the trough by Sat. Active convection near this low this afternoon will continue overnight. A cold front NW of the area is expected to gradually shift SE over the next few days and reach near 30N140W by Sun morning, then shift slowly SE into the far NW waters and dissipate. Associated NW swell will move into the NW waters early Sun just ahead of the front and raise seas to 8-10 ft to the northwest of a line from 30N133w to 21N140W by Sun afternoon. Strong high pressure behind the front will build across NW and N portions Sun and Mon and induce the strong winds and building seas to the W of Baja California mentioned above. $$ Stripling