Tropical Weather Discussion
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282 AXNT20 KNHC 121651 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1805 UTC Wed Jun 12 2024 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 1200 UTC surface analysis and satellite imagery through 1650 UTC. ...SPECIAL FEATURES... Heavy Rainfall over some portions of the southeastern Gulf of Mexico, parts of the Florida Peninsula, and the western Atlantic: Abundant tropical moisture is surging northward from the western Caribbean, across the southeastern Gulf of Mexico, also over portions of Florida, and across the adjacent western Atlantic waters. This moisture is practically to the southeast of a surface trough that extends from west-central Florida to a broad and elongated area of low pressure (Invest AL90). A surface trough continues from this area of low pressure southwestward to eastern Bay of Campeche, where numerous scattered convection is depicted. In addition, upper- level diffluent flow present across the region is helping to support clusters of disorganized scattered to numerous showers and thunderstorms that extend from 22N, northeastward across the far southeastern Gulf of Mexico, the Straits of Florida to along and over parts of Florida. This activity also reaches into the western Atlantic west of 75W. Cloud to surface lightning, strong gusty winds, rough seas and low visibility are ongoing within this convective activity over these areas. The shower and thunderstorm activity is expected to continue across the region through Fri. Mariners transiting these regions should exercise caution. Please refer to bulletins and forecasts from your local weather forecast offices for specific local information. ...TROPICAL WAVES... A far eastern Atlantic tropical wave has its axis along 23W from 03.5N to 12N. It is moving westward at 10-15 kt. Numerous moderate convection exists from 03N to 12N between the wave axis and 29W. A central Atlantic tropical wave has its axis along 36.5W from 02N to 14N, moving westward around 15 kt. No significant convection is depicted at the moment in association with this wave. A central Caribbean tropical wave has its axis near 70W south of 13N moving westward at 10-15 kt. Isolated showers and thunderstorms are near the northern tip of the wave. A western Caribbean tropical wave has its axis near 78.5W south of 14N. It is moving westward at 10-15 kt. This wave is becoming ill defined as it encounters low to middle-level southeast wind flow surging into the northwestern Caribbean Sea. Scattered showers and thunderstorms are depicted from 13N to 09N between 74W and 81W. ...MONSOON TROUGH/ITCZ... The monsoon trough axis extends from 12N17W southwestward to 10N19W. The ITCZ extends from 08N25W to 06.5N35W and from 06N39W to 06N52W. Scattered moderate to isolated strong convection is from 05N to 08N between the west coast of Africa and 18W. Similar activity is from 05N to 08N between 49W and 58.5W. ...GULF OF MEXICO... Please read the SPECIAL FEATURES section for information about heavy rainfall over the far southeastern Gulf of Mexico. A stationary front extends from northeast Florida to southeastern Louisiana and westward from there to inland Texas near Houston/Galveston area. Elsewhere, a trough extends from central Florida south-southwestward to the broad and elongated area of low pressure described above under Special Features. The trough continues from the low southwestward to 24N87W, and to the the west of the Yucatan Peninsula. Light to gentle generally variable winds are found across the basin, except for moderate to locally fresh southeast to south winds between the western tip of Cuba and the northeast part of the Yucatan Peninsula. Seas are in the range of 2 to 4 ft. Hazy conditions are over the SW Gulf due to ongoing agricultural fires are in Mexico. For the forecast, the aforementioned elongated area of low pressure is forecast to move northeastward offshore of the U.S. Southeast coast tonight through late week. As a result, unsettled weather in the form of numerous showers and thunderstorms with gusty winds will persist over the eastern Gulf through Fri night as a trough lingers over the Gulf. Hazy conditions due to agricultural fires over Mexico will continue to affect the western Gulf reducing visibility to around 3 nm at times through at least the next couple of days. Looking ahead, a broad area of low pressure could form over the weekend across the southwestern Gulf of Mexico. Environmental conditions appear conducive for some slow development early next week while the system moves slowly westward or west-northwestward. ...CARIBBEAN SEA... The pressure gradient between Atlantic high pressure, lower pressures in the deep tropics, and the trough of low pressure across the southeastern Gulf of Mexico is resulting in moderate to fresh east to southeast winds over most of the basin, with the exception of the central basin, where winds are fresh to strong. Seas range from 7 to 9 ft over the central Caribbean and 4 to 6 ft elsewhere. Isolated showers and thunderstorms are over some areas of the northwestern Caribbean and from just south of central Cuba to near 15N. For the forecast, high pressure located NE of the area combined with the Colombian low and the passage of tropical waves will support fresh to strong trade winds across the central Caribbean through Thu night. Moderate to fresh southeast winds are expected over the northwestern Caribbean likely through Fri as a trough of low pressure remains over the eastern Gulf of Mexico. Otherwise, scattered showers and thunderstorms are forecast to continue across portions of the northwestern Caribbean through the rest of the week as a surge of tropical moisture persists across the region. ...ATLANTIC OCEAN... Please read the SPECIAL FEATURES section above for more information about the heavy rainfall over the western Atlantic. A stationary front extends from low pressure of 1014 mb that is north of the area near 32N76W southwestward to 31N80W and to inland northern Florida. Meanwhile, unsettled weather in the form of numerous showers and thunderstorms, with locally gusty winds and higher seas, are over most of the western part of the forecast waters as well as inland some sections of central and South Florida and Straits of Florida as upper-level disturbances continue to move from W to E along and near the stationary front in combination with additional moisture being channeled eastward across the Florida peninsula from the broad and elongated area of low pressure that is over Florida. A surface trough supported by an upper-level low is analyzed from near 29N37W to 18N46.5W. Overcast mostly mid-level clouds with embedded isolated showers and thunderstorms are noted from 22N to 29N between 37W and 45W. A weak trough is from 21N51W to 17N56W. No significant convection is noted with the trough. Another trough extends from 30N59W to 21N56W. No significant convection is depicted with the trough. A 1021 mb high center is near 30N63W. Strong high pressure of 1034 mb located well north of the discussion area in the vicinity of the Azores has an associated ridge that reaches southwestward to the central Bahamas. The pressure gradient between this ridge, the 1014 mb low just north of the area and the stationary front off the southeastern U.S. coast supports fresh to strong south to southwest winds north of 27N between 74W and 80W. Seas over these waters are 4 to 7 ft. The remainder of the subtropical Atlantic is under the influence of the gradient related to the 1034 mb Azores high, which is supporting mainly fresh to localized strong northeast winds between the coast of W Africa and the Cape Verde Islands. South of the ridge, moderate to locally fresh trade winds are over the tropical Atlantic waters, where seas are 4 to 7 ft. Saharan Air dominates the lower to middle atmosphere across the Atlantic from about 10N to 20N and roughly between Africa and the Lesser Antilles. For the forecast W of 55W, an elongated area of low pressure over the Florida peninsula is producing a large area of disorganized showers and thunderstorms. Although upper-level winds are expected to be only marginally conducive, some slow development is possible while the system moves northeastward offshore of the U.S. Southeast coast tonight through late week. Unsettled weather in the form of numerous showers and thunderstorms, with gusty winds and higher seas, are over most of the western part of the forecast waters W of 70W. Expect for little change with this convective activity into the end of the week. Fresh to strong southerly winds are expected over the western Atlantic ahead of this system during the next couple of days. $$ KRV