000 AXPZ20 KNHC 181559 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Wed May 18 2022 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 1200 UTC surface analysis and satellite imagery through 1510 UTC. ...SPECIAL FEATURES... A broad area of low pressure is forecast to form across the western Caribbean and then shift across Central America late this week into the weekend. This is the climatologically favored time of year for these broad low pressure areas, called Central American Gyres, to develop. CAG's increase SW monsoon flow, and lift the monsoon trough well north of its typical position, which advects abundant moisture northward. This CAG will bring an increase in convection, starting Thursday over the southern portions of Central America, which will gradually lift north and northwestward across portions of Central America and across the waters west of Central America, as the monsoon trough lifts northward. There will be the potential for locally heavy rainfall over portions of Central America, especially in regions of enhanced orographic lift. Flash flooding and mudslides will be possible in areas that receive the heaviest rainfall. Please refer to products issued by your local weather service for more information. ...TROPICAL WAVES... A tropical wave extends from the southwest Caribbean along 79W/80W southward across Panama and into the tropical northeast Pacific to near 03N., and is moving westward at 15-20 kt. Scattered moderate to strong convection is occurring across the Pacific waters north of 02N east of 81W, but is scattered to numerous across the southwest Caribbean and interior Columbia to the N and E of the wave axis. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 10N81W to 09N109W to low pres near 08.5N119.5W 1012 mb to 08N127W. The ITCZ extends from 08N127W to beyond 06N140W. Scattered moderate to strong convection is noted north of 02N east of 81W, and from 05N to 13N between 81W and 105W. Scattered moderate isolated strong convection is noted elsewhere within 90 nm either side of the trough and ITCZ between 109W and 140W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Moderate to fresh NW winds prevail off the coast of the Baja California Norte. Gentle to moderate NW winds are west of Baja California Sur. Moderate to locally fresh southerly winds prevail across the Gulf of California. Light to gentle mainly NW to W winds are elsewhere over the open waters off Mexico. Seas are in the 7-10 ft range in NW swell off Baja California Norte, 5-8 ft off the coast of Baja California Sur, and 5-6 ft elsewhere over the remainder of the open waters off Mexico. Seas are in the 2-4 ft range over the Gulf of California, highest near the entrance of the Gulf. Haze has been reported at coastal sites from the southern Gulf of California southward to Tehuantepec due to seasonal agricultural fires over Mexico. Moderate to locally fresh winds will prevail west of Baja California today before diminishing to gentle to moderate. Moderate to locally fresh southerly flow in the Gulf of California will persist today. Fresh to locally strong S-SW may develop in the northern Gulf of California early Fri through Fri night. Moderate to locally fresh W-NW winds will develop from near Cabo San Lucas to near Cabo Corrientes to offshore Oaxaca tonight through the end of the week. NW swell will prevail across the waters off Baja California Norte through the week, subsiding late this weekend. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, and WITHIN 750 NM OF ECUADOR... Please see the Special Features section for information on the development of a potential heavy rainfall event. Gentle to locally moderate S to SW monsoon flow prevails south of the monsoon trough. Light to gentle winds prevail north of the monsoon trough, except moderate to fresh winds offshore southern Nicaragua. Seas are in the 5-7 ft range in S to SW swell. Some haze has been reported at coastal sights from Nicaragua northward due to nearby agricultural fires. Gentle to moderate winds will prevail south of the monsoon today, increasing to moderate to fresh Thu through Fri. Light to gentle winds will prevail north of the monsoon trough through Fri night, except moderate over Papagayo and offshore southern Nicaragua today. A moderate long-period southerly swell will linger today, with a slightly increase of new southerly swell arriving by Thu. Moderate to fresh SW winds will shift northward to 09N on Fri, with the monsoon trough, as the CAG described above in the special features section begins to develop. REMAINDER OF THE AREA... High pressure prevails over the waters north of the ITCZ and monsoon trough and west of 110W, centered on a 1030 mb high near 35N136W. The pressure gradient between the ridge and lower pressure in the vicinity of the ITCZ and within the monsoon trough is maintaining moderate to locally fresh winds and seas of 6-7 ft north of the ITCZ and monsoon trough to 28N and west of 118W, and locally fresh to strong north of 27N between 120W and 127W with 7-9 ft seas in fresh northerly swell. Gentle to moderate anticyclonic winds and 3-5 ft seas are north of 28N and west of 129W near the high center. Gentle to moderate southerly winds and 5-7 ft seas are noted south of the ITCZ and monsoon trough and west of 106W, except 7 to 8 ft south of 10N between the Galapagos Islands and 118W. East of 110W, light to gentle to winds are noted on either side of the monsoon trough with 4-7 ft seas. Fresh to strong northerly winds will extend from offshore southern California into the waters north of 27N between 120W and 130W through the end of the week, along with seas in the 7-10 ft range in fresh northerly swell. Otherwise, little change in conditions are expected across the open waters through the week with tranquil marine conditions anticipated this weekend. $$ Stripling