000 AXNT20 KNHC 152021 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0005 UTC Mon May 16 2022 Tropical Weather Discussion for North America, Central America Gulf of Mexico, Caribbean Sea, northern sections of South America, and Atlantic Ocean to the African coast from the Equator to 31N. The following information is based on satellite imagery, weather observations, radar and meteorological analysis. Based on 1800 UTC surface analysis and satellite imagery through 1930 UTC. ...TROPICAL WAVES... A tropical wave is across the Windward Islands with axis south of 17N and along 61W/62W, moving west at 15 kt. The wave is in a unfavorable wind shear environment with no significant convection noted. Winds associated with this wave are in the 15-20 kt range with seas in the 6-8 ft range just east of the Windward Islands. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from the coast of Africa near the border of Sierra Leone and Guinea near 09N13W to 07N18W where the ITCZ begins and continues to the Equator at 30W and then along the Equator to northern Brazil near 50W. Scattered moderate convection is noted from 03N to 06N between 12W and 15W, and south of 05N between 30W and 49W. Scattered moderate and isolated strong convection is noted south of 07N between 49W and 60W, including over portions of northern South America. GULF OF MEXICO... A middle to upper level short-wave trough over the NE Gulf of Mexico and shallow moisture continue to support and area of scattered showers and thunderstorms as indicated by GLM data. A surface trough coincides with that region of convection, which extends from the Florida Big Bend to 25N90W. A 1014 mb surface low is along the trough near 27.5N87W. The remainder basin is under the influence of weak high pressure anchored by a 1017 mb high centered near 27N93W, which is providing light to gentle variable winds across the basin, except moderate in the Texas coastal waters and in the west-central Gulf offshore waters. Seas are 1 ft or less east of 90W and in the 1-3 ft range west of 90W. Ongoing agricultural fires in Mexico are producing some areas of slight to moderate haze mainly in the southwestern sections of the Gulf of Mexico. For the forecast, high pressure over the area will continue to produce a gentle to moderate anticyclonic flow through midweek. Fresh northeast winds will pulse west of the Yucatan peninsula each night through Wed night. Fresh southeast return flow is expected over the NW and west-central Gulf beginning on Wed night due to a tighter pressure gradient over the western Gulf. CARIBBEAN SEA... Isolated showers and thunderstorms prevail over portions of the central and western Caribbean between 74W and 84W associated with a surface trough south of 22N with its axis along 83W/84W. The convection is also being supported by abundant moisture and middle-to-upper level diffluent flow just to the east of a trough aloft. East of the trough, moderate to fresh E-SE winds prevail, along with seas in the 4-7 ft range, except locally to 8 ft northwest of the northern coast of Colombia. Light to gentle N-NE winds and seas in the 2-4 ft range prevail elsewhere. For the forecast, the pressure gradient across the basin will continue to support fresh to strong trades across the eastern and central Caribbean through tonight. Thereafter, moderate trade winds will prevail across the basin, except for pulsing fresh to strong easterly winds over the southern portion mainly N of Colombia and in the Gulf of Venezuela. A tropical wave along 61W/62W will move across the eastern Caribbean from tonight through Tue. Moisture accompanying this wave is expected to increase the chances for showers in the eastern Caribbean through midweek. ATLANTIC OCEAN... The subtropical Atlantic remains under the influence of the Bermuda High, which is anchored by a 1023 mb center north of the area near 34N59W. To the northeast of the Bahamas, between 67W and 73W, middle-to-upper level moisture streaming from the NW Caribbean and Straits of Florida supports an elongated area of scattered showers and thunderstorms with earlier scatterometer data indicating gusty winds, especially north of 29N between 68W and 72W. Otherwise, the Bermuda high continues to support mainly moderate to fresh return flow SW of the high between 60W and 74W with seas in the 4-6 ft range. Over the eastern Florida seaboard, winds are light to gentle and variable with seas in the 3-5 ft range in SE swell. To the east, a dissipating stationary front extends from 31N30W to 29N40W with some isolated showers possible near it. A 1022 mb high is south of the front near 24N37W with a ridge axis extending from the Canary Islands through the high to the Bermuda high. Light to gentle anticyclonic winds and seas of 3-4 ft are within 150 nm of the ridge axis. Moderate to locally fresh winds prevail elsewhere, except fresh to strong near the Cabo Verde Islands northeast to the coast of Africa from 19N to 23N east of 25W. Seas are in the 5-8 ft range in NE swell south of 20N, highest west of 40W, and in the 4-7 ft range elsewhere over the open tropical Atlantic waters. For the forecast west of 55W, high pressure over the area will change little through Mon. The high will shift eastward as a cold front approaches from the northwest on Tue. The front is expected to reach the northeast part of the area on Wed, with moderate to fresh southwest winds preceding it. High pressure will rebuild across the basin toward the end of the week. $$ Lewitsky