000 AXPZ20 KNHC 200407 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 UTC Fri May 20 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 0000 UTC surface analysis and satellite imagery through 0300 UTC. ...SPECIAL FEATURES... A broad area of low pressure is forecast to form across the western Caribbean and Central America tonight into the weekend, and shift west to northwestward. This is the climatologically favored time of year for these broad low pressure areas, called Central American Gyres, to develop. CAG's increase the strength of 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 today over the southern portions of Central America, which will gradually shift north and northwestward across portions of Central America and the adjacent 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... The axis of a tropical wave extends from offshore of the Gulf of Honduras along 85W southward across Central America and into the tropical northeast Pacific to near 05N, and is moving westward at 10 to 15 kt. Scattered to locally numerous convection is discussed in the ITCZ/monsoon trough section below and extends northward into the southwest Caribbean. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A monsoon trough extends from near the Nicaragua-Costa Rica border across 09N105W to 07N129W. An ITCZ continues from 07N129W to beyond 140W at 06N. Scattered moderate convection is noted from 05N to 13N between 86W and 120W, and from 06N to 09N between 120W and 140W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Gentle to moderate NW winds prevail off the coast of the Baja California peninsula, and also extends from near Cabo San Lucas to near Cabo Corrientes to offshore of Oaxaca. Gentle to locally moderate 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 7-9 ft range in NW swell off Baja California Norte, 6-7 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 1-3 ft range over the Gulf of California, highest near the entrance of the Gulf. Haze continues to be reported at coastal sites from the entrance of Gulf of California southward to Tehuantepec due to seasonal agricultural fires over Mexico. Gentle to moderate winds will prevail west of the Baja California peninsula through the weekend. Fresh to locally strong S-SW will develop in the northern Gulf of California early Fri through Sat morning, when seas are expected to build to 6-7 ft. Westerly gaps winds will briefly develop across the rest of the Gulf tonight through late Fri morning. Moderate to locally fresh W-NW winds will prevail from near Cabo San Lucas to near Cabo Corrientes to offshore Oaxaca through the end of the week, with strongest winds expected near the Cabo San Lucas coast. 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 moderate S to SW monsoon flow prevails south of the monsoon trough. Light to gentle winds prevail north of the monsoon trough. Seas are in the 5-7 ft range in S to SW swell. Some haze has been reported at coastal sights from El Salvador northward to southern Mexico due to nearby agricultural fires. Winds south of the monsoon trough will increase to moderate to fresh through Fri, and spread N to 09N tonight through early Sat. Light to gentle winds will prevail north of the monsoon trough through early Fri night. Long-period southerly swell over the regional waters will increase slightly through Fri before slowly subsiding. Active weather is expected to gradually shift W-NW from the eastern waters to along 90W through Sat. REMAINDER OF THE AREA... High pressure prevails over the waters north of the ITCZ and monsoon trough and west of 110W, centered on a 1033 mb high near 36N136W. 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 6-8 ft north of the ITCZ and monsoon trough and west of 125W, and locally fresh to strong north of 27N between 122W and 132W, where seas are 7-10 ft in fresh northerly swell. Gentle to moderate southerly winds and 5-7 ft seas are noted south of the ITCZ and monsoon trough and west of 102W, except 7 to 8 ft south of 10N between the Galapagos Islands and 112W. Very active weather, described above, continues this afternoon from 05N to 10N between 90W and 110W. 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, only a very slight decrease in winds and seas is expected across the open waters S of 22N and W of 125W, with tranquil marine conditions anticipated through this weekend. $$ Chan