Tropical Weather Discussion
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796 AXNT20 KNHC 132254 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0005 UTC Fri Jun 14 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 1800 UTC surface analysis and satellite imagery through 2230 UTC. ...SPECIAL FEATURES... Heavy Rainfall over the southeastern Gulf of Mexico, portions 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 resides to the southeast of a surface trough that extends from near 31N79W southwestward to east- central Florida north of Cape Canaveral. An elongated area of low pressure (Invest AL90) is centered near 29N79W with a pressure of 1010 mb. The trough continues southwestward to near Tampa, Florida to 24N88W and to the central Bay of Campeche. Also, upper- level diffluent flow is present across the region. As a result, numerous showers and scattered thunderstorms are present southeast of the trough from 22N to 31N between 73W and 86W. In addition numerous thunderstorms are quickly developing over the Yucatan Peninsula and the Bay of Campeche south of 22N. Cloud to surface lightning, strong gusty winds, rough seas and low visibility are ongoing within this convective activity. The shower and thunderstorm activity is expected to continue across the region through at least Fri. Mariners transiting these regions should exercise caution. Please refer to bulletins and forecasts from your local weather forecast offices for specific local information. Heavy Rainfall over Central America and Mexico: A barotropic Central American Gyre (CAG) is rapidly developing. Observations are indicating that heavy rainfall is already occurring before the main event that is forecast to begin Sunday morning, June 16 through the morning of Friday June 21. The persistence of moist onshore flow in the Pacific basins of Guatemala, Chiapas, Honduras and in El Salvador will favor 3-4 days of intermittent rounds of heavy precipitation. Please refer to bulletins and forecasts from your local weather forecast offices for specific local information. ...TROPICAL WAVES... A new tropical wave has been analyzed, with axis along 15W and N of 03N. Scattered moderate convection is noted from 03N-12N and E of 23W. A central Atlantic tropical wave has its axis along 34W from 03N to 12N, moving westward near 15 kt. Scattered showers are developing along the wave axis mainly over the northern half of the wave environment. An Atlantic tropical wave has its axis along 51W from 02N to 14N, moving westward at about 15 kt. NO significant convection is noted at this time with this wave. A Atlantic tropical wave has its axis along 62W south of 12N eastern Venezuela. The wave is moving west at 10 to 15 kt. Scattered showers remain over land. A western Caribbean tropical wave has its axis along 82W south of 14N, moving westward at 5 to 10 kt. Scattered moderate convection prevails S of 12N. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from near 13N17W to 08N23W. The ITCZ begins at 08N23W and continues to 05N50W. Aside from the convection described in the tropical waves section above, scattered moderate convection is noted from 03N-09N between 41W-50W. ...GULF OF MEXICO... Please read the Special Features section above for information about the ongoing heavy rainfall over the southeastern Gulf of Mexico and the upcoming rainfall event over Mexico. A stationary front extends from northeast Florida near 30N85W to 29N95W. A surface trough is analyzed from 28N83W to 18N94W. Scattered to numerous showers and thunderstorms are southeast of the trough impacting most of the southeastern Gulf and waters just offshore the northern Yucatan Peninsula. Outside of convection, light to gentle variable winds prevail west of the trough, with moderate south to southwest winds east of the trough. Seas are 1 to 3 ft west of the trough, and 3 to 4 ft east of the trough. Hazy conditions are over the SW Gulf due to ongoing agricultural fires are in Mexico. For the forecast, the aforementioned trough is expected to gradually weaken through late Fri. Looking ahead, a broad area of low pressure is forecast to form over the southwestern Gulf of Mexico late this weekend or early next week. Environmental conditions appear conducive for gradual development of this system, and a tropical depression could form during the early or middle part of next week while it moves slowly westward or west-northwestward. Increasing winds and building seas are expected with this system. ...CARIBBEAN SEA... Please read the Special Features section above for more information about the upcoming Rainfall event over Central America and Mexico, and the Tropical Waves section for information about the 2 waves moving across the basin. 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, except for the waters N of Colombia, where winds are fresh to strong. Seas range from 7 to 8 ft over the central Caribbean and 4 to 6 ft elsewhere, except 3 to 5 ft east over the southwestern Caribbean. 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 south-central Caribbean through Fri. 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. Looking ahead, expect increasing winds and building seas over the western Caribbean, including the Gulf of Honduras, over the upcoming weekend as a broad area of low pressure is forecast to form over the southwestern Gulf of Mexico. ...ATLANTIC OCEAN... Please read the Special Features section above for more information about the heavy rainfall over the western Atlantic and near and over portions of the Florida peninsula, and the Tropical Waves section for information about the 3 waves moving across the basin. Deep convection over the western Atlantic is described above in the Special Features section. Fresh to strong winds and 5 to 7 ft seas are north of 27N W of 73W. To the east, 3 surface troughs are analyzed along 63W, 56W and 45W. Scattered showers are are noted along all the troughs. Elsewhere, strong high pressure of 1033 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. Gentle to moderate winds and seas of 3 to 6 ft seas dominate the basin west of 35W. Moderate to fresh trade winds east of 35W, except for fresh to strong northeast winds from the Cabo Verde Islands to the Canary Islands, including along the coast of Africa. Seas are 5 to 7 ft across this area. 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 west of 55W, the elongated area of low pressure offshore the southeastern U.S coast could experience some gradual development while the system moves northeastward offshore of the southeastern U.S. coast during the next day or so. Gusty winds, higher seas and frequent lightning will be associated with this convective activity forecast to persist through at least Fri. Fresh to strong southerly winds are expected over the western Atlantic ahead of this system during the next couple of days. As the low pressure departs, high pressure will build southward over the western Atlantic beginning this weekend and into early next week. $$ ERA