000 AXPZ20 KNHC 052219 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 UTC Mon Feb 5 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 2115 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A surface trough extends from 09N71W TO 01N82W TO 04N100W. The ITCZ continues from 04N100W to 04N113W TO 07N125W TO BEYOND 07.5N140W. Scattered moderate isolated strong convection is noted within 150 nm N of the ITCZ between 102W and 134W. A persistent deep layered trough continues to produce active convection between 115W and 126W this morning. Scattered moderate to strong convection is noted from 13N to 20N between 116W and 126W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A 1029 mb high pressure center is located over the NE Pacific near 41N134W and extends a weak and elongated ridge SE into the offshore waters to SE of the Revillagigedo Islands. The pressure gradient along and offshore of the Baja California peninsula is yielding gentle to moderate NW winds this afternoon, with seas generally 3 to 5 ft. This fairly quiet pattern is expected to prevail through Wednesday. Long period NW swell will cause seas to build to 5-7 ft along the offshore waters N of 20N Tue and Wed. Seas in this region will then begin to subside on Thu. Light to gentle winds and 3 to 5 ft seas will prevail along the Pacific coast of Baja Fri and Sat. Gulf of California: Light to gentle winds and 1 to 3 ft seas will generally prevail through Wednesday. A modest increase in NW winds during the end of the week will allow seas to build to 3-4 ft, possibly as high as 5 ft Wed evening through Thursday. Gulf of Tehuantepec: Moderate northerly winds are expected to prevail across the Gulf waters for the next few days, and will pulse fresh and strong at night through around sunrise each of the next few days due to the influence of nocturnal drainage flow. The pressure gradient will tighten by early Thu as high pres builds southward along the Sierra Madre Oriental mountains of Mexico toward the Isthmus of Tehuantepec, while a cold front moves into the NW Gulf of Mexico. Another gale force gap wind event may commence over the Gulf of Tehuantepec Thu evening through Fri night as this pattern develops. This event will peak on Fri morning and produce an area of 8 ft seas that will merge with the area of 8 ft seas propagating downwind from the Gulf of Papagayo. The merged area will spread as far S as 06N and as far W as 105W. Winds over the Gulf will taper to light and variable by Sat night. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Fuego Volcano in Guatemala: Intermittent expulsions of volcanic ash from the volcano occurring during the past several days have not been detected during the overnight and early morning hours. No lingering ash is evident in satellite imagery extending W or SW across the regional waters. Nocturnal winds will pulse to between fresh and strong speeds each night over the Gulf of Papagayo through the week. Areal coverage of gap winds near the Gulf of Papagayo will increase Thu and Fri. This will allow the wind generated seas of 8 ft to propagate further downwind from the Gulf of Papagayo and merge with the area of 8 ft seas downwind from the Gulf of Tehuantepec on Fri and Sat. Elsewhere N of 09N, gentle to moderate offshore flow will prevail. Moderate to fresh winds will pulse to strong during overnight hours in the Gulf of Panama as well through Wed morning, becoming moderate to fresh Thu and Fri. Otherwise, light to gentle S to SW winds will generally prevail S of 09N through Fri night. REMAINDER OF THE AREA... The ridge of high pressure mentioned above also extends S across the NW part of the discussion area this afternoon, and will persist during the next several days. NW swell generated by a fetch of winds to the W of a nearly stationary frontal boundary currently NW of the Hawaiian Islands has spread across the W portion of the discussion area and is generating seas of 8 to 9 ft W OF LINE FROM 30N130W TO 19N130W TO 08N140W. This swell will continue to propagate SE and decay and subside below 8 ft by Tue night. The next significant pulse of NW swell is not expected to enter the area waters until Fri night. Weather for the remainder of the week looks benign with only light to moderate winds and 4-7 ft seas beyond 250 nm offshore. A persistent surface trough currently along 125W-126W between 12N and 21N is producing active convection along and E of the trough, described above and supported by a broad upper level cyclone there. The trough will remain near its current location and eventually dissipate by Sat, with weather gradually diminishing in coverage. $$ Stripling