000 AXPZ20 KNHC 051617 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 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 1200 UTC surface analysis and satellite imagery through 0845 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 120W and 130W this morning. Scattered moderate to strong convection is noted from 10N to 20N between 117W and 128W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A 1029 mb high pressure center is located over the NE Pacific near 43N133W 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 morning, 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 begin building to between 5 and 7 ft along the offshore waters N of 20N Tue and Wed. Seas in this region will 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 Fri night. 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 early Thu 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 area of 8 ft seas 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 and SW across the NW part of the discussion area this morning, 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 are generating seas of 8 to 10 ft from 10N to 30N W of 132W. The swell will continue to propagate SE and decay. The area of combined seas greater than 8 ft will eventually stretch from 10N to 30N between 127W and 140W by Mon evening. This area of seas will subside below 8 ft by Tue night as the underlying NW swell continue to decay. 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 10N 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