000 AXPZ20 KNHC 291011 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 850 UTC Fri May 29 2020 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 0600 UTC surface analysis and satellite imagery through 0800 UTC. ...SPECIAL FEATURES... A Central American Gyre will develop in the eastern North Pacific within the next couple days and move northward, gradually encompassing Central America and southern Mexico. This will advect abundant moisture into portions of Central America through the weekend and into next week. Heavy rainfall is expected over portions of Central America and southern Mexico, especially over southern Guatemala, El Salvador, southern Honduras, and western Nicaragua. This will bring the potential for life-threatening flash floods and mudslides for locations that receive the heaviest rainfall, especially in areas of mountainous terrain. Please refer to products issued by your local weather service for more details. Tropical cyclogenesis is possible in association with this Central American Gyre. There is currently a medium chance of tropical cyclone formation within the gyre over the next couple of days, and a high chance of tropical cyclone formation within the next five days. Please see the latest Tropical Weather Outlook for more information. ...TROPICAL WAVES... The axis of a tropical wave is along 95W north of 08N, moving west 5 to 10 kt. Scattered moderate isolated strong convection is noted within 180 nm either side of the wave from 07N to the coast along the Gulf of Tehuantepec. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 11N82W TO 11N91.5W TO 1012 mb low pres near 09N113W TO 1012 mb low pres near 09N122W TO 11N131W TO 08N138W. ITCZ extends from 08N138W to beyond 07N140W. Scattered moderate to strong convection is noted from 03.5N to the coasts between 81W and 96W. Scattered moderate isolated strong convection noted from 03.5N TO 11N between 97W and 129W, and from 06.5N TO 14N W of 132W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see the Special Features section for more details on the Central American Gyre expected to develop within the next couple days, as well as the potential for tropical cyclone formation offshore of southern Mexico and Central America. Recent scatterometer data showed gentle to moderate NW winds prevailing off the coast of Baja California and southern Mexico to Puerto Angel. Moderate cyclonic winds were noted wrapping around Baja California Sur and Los Cabos and into the southern Gulf of California. Seas of 4-6 ft persist over the Baja California Sur offshore waters eastward to near Cabo Corrientes. Wave heights ranging between 5-7 ft prevail over the southern Mexico offshore waters in SW swell. A developing Central American Gyre and possible tropical cyclone formation are expected to produce increasing winds and seas over the southern Mexico offshore waters this weekend. Strong to near gale-force N winds are expected this weekend over the Tehuantepec region. Elsewhere, high pressure will build over the northern waters Fri night into the weekend, resulting in moderate to fresh NW winds off the coast of Baja California. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Please see the Special Features section for more details on the Central American Gyre expected to develop within the next couple days, as well as the potential for tropical cyclone formation offshore of Central America. Scattered moderate convection persists along the monsoon trough offshore of Guatemala, El Salvador, Nicaragua, and Costa Rica. Moderate southerly flow is noted on earlier scatterometer data south of the monsoon trough, while strong offshore winds were noted offshore of the Gulf of Papagayo region. Seas remain in the 4-7 ft range across much of the area, except to near 8 ft downstream of the Papagayo region. Hazardous marine conditions will develop later today into early next week as winds and seas increase over the offshore waters, in association with a developing Central American Gyre and possible tropical cyclone formation. A tropical depression is likely to form within the gyre this weekend offshore of Guatemala and El Salvador and drift northward. Long-period SW swell will continue propagating across the region through early next week. REMAINDER OF THE AREA... Deep layered low pressure across northern portions supports a weak 1014 mb low pressure is analyzed near 28N129W, with a surface trough extending from the low south then southwest to near to 20N130W. Isolated moderate convection is noted within 120 nm of the low across the southeast semicircle. Moderate to fresh NNE winds were depicted by recent scatterometer data N of 25N to the west of the low, where wave heights are up to 7-8 ft. Elsewhere gentle to locally moderate NE trades prevail N of the monsoon trough to 20N. Low pressure along the monsoon trough near 09N113W is still producing fresh westerly winds south of the monsoon trough. An area of 8-10 ft seas in SW swell persists roughly from 04N to 10N between 90W and 110W. A high pressure ridge will build across the northern waters this weekend. Otherwise, little change in marine conditions is expected over these outer waters over the next couple days. $$ Stripling