Special Features

Potential Tropical Cyclone One is centered along the Texas coast near 28.0N 96.7W at 0900 UTC, or 35 nm SW of Port O'Connor, Texas, moving NE at 5 kt. Estimated minimum central pressure is 1003 mb. Maximum sustained wind speed is 25 kt with gusts to 35 kt. Peak seas are currently around 9 ft. A large cluster of strong showers and thunderstorms continues 120 to 360 nm to the E through SE of the center of One, and well east of the center. The system is is expected to accelerate northeastward today, and straddle the coast most of the day, before moving farther inland over eastern Texas or Louisiana tonight. One is forecast to gradually strengthen and become a tropical storm later today just before landfall. Tropical-storm-force winds are expected along the Louisiana coast today from Sabine Pass to Morgan City where a Tropical Storm Warning is in effect. Weakening is anticipated by tonight when the system moves farther inland across Louisiana. One is expected to produce rainfall totals of 5 to 10 inches, with isolated higher totals near 20 inches, through Thursday from the Mid and Upper Texas coast east-northeast into southern and central portions of Louisiana, Mississippi, and Alabama, along with western portions of Georgia and the Florida Panhandle. This could generate dangerous to life- threatening flash flooding.

Please read the latest HIGH SEAS FORECAST issued by the National Hurricane Center at website - https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml and the latest One NHC Forecast/Advisory and Public Advisory at www.hurricanes.gov for more details.

Tropical Waves

A new tropical wave is along the west coast of Africa, along 14W, south of 17N, moving west around 10 kt. Scattered moderate to strong convection is noted from 03N to 12N E of 19W to the coast.

An eastern Atlantic tropical wave is along 33W, south of 17N, moving westward at 15 kt. Scattered moderate convection is present from 04N to 09N and between 30W and 41W.

An Atlantic tropical wave is along 55W, south of 17N, moving westward at 15-20 kt. Widely scattered moderate convection follows the wave from 06.5N to 09.5N between 45W and 53W.

A central Caribbean tropical wave is along 73W, south of 17N, moving westward at 15-20 kt. Isolated moderate convection is about the wave axis.

A western Caribbean tropical wave is along 86W, south of 18N extending into the eastern Pacific, moving westward at 15-20 kt. The wave is enhancing moderate shower and thunderstorm activity over Central America.

Monsoon Trough/ITCZ

The monsoon trough enters the Atlantic through the coast of Guinea-Bissau near 12N16W and continues southwestward to 06.5N32W. The ITCZ extends from 06N35W to the coast of Brazil near 01N50W. Other than convection described above associated with the tropical wave, scattered moderate convection is observed from 03N to 09N between 20W and 30W, and S of 03N between 46W and 50W.

Gulf Of America

Please refer to the Special Features section above for details on Potential Tropical Cyclone One along the southern Texas coast.

Very moist southerly low level wind flow is combining with a middle to upper-level trough across the extreme NW Gulf, and Potential Tropical Cyclone One, to produce a large cluster of strong convection over the NW Gulf waters, 120 nm east of One. Generally dry conditions prevail elsewhere over the basin. Recent satellite scatterometer date showed moderate to fresh southerly winds across the NW Gulf north of 22N and to the north of the Yucatan Peninsula. Seas are 4 to 7 ft across the waters and 6 to 9 ft within the area of strong convection. Outside of the influence of PTC One, moderate SE to S winds and moderate seas prevail W of 85W, with light to gentle winds and slight to moderate seas to the E of 85W.

For the forecast, Potential Tropical Cyclone One will move NE and along or just offshore of the Texas coast today, reaching near 29.1N 95.2W this afternoon as a Tropical Storm, and then inland near 31.1N 92.8W tonight as a remnant low, before dissipating Thu across south-central Louisiana. Large SW to S waves generated by the Potential Tropical Cyclone are likely to cause large and dangerous surf and life- threatening rip current conditions along the northwestern and north-central Gulf Coast for the next couple of days. Otherwise, a tightening pressure gradient will develop over the basin and sustain fresh to strong southerly winds over the western and central Gulf late Wed through Thu night, and moderate to fresh winds over the eastern Gulf. Winds and seas will begin to diminish late Fri through the weekend as weak high pressure settles over the eastern Gulf.

Caribbean Sea

The broad subtropical ridge across the western Atlantic extends along 27N-28N and into south Florida. This pattern is forcing fresh to strong easterly trade winds and moderate to rough seas in the central Caribbean and across the Gulf of Honduras, with the strongest winds and highest seas to 9 ft occurring off NW Colombia. Moderate to locally fresh trades and moderate seas are found in the eastern and NW Caribbean. Elsewhere, especially in the lee of Cuba, Windward Passage and south of 12N, light to gentle winds and slight to moderate seas prevail. A cluster of strong thunderstorms has moved westward off of NW Colombia and into the SW Caribbean and across eastern portions of Panama. A lingering middle to upper-level trough continues to support moderate nocturnal convection across eastern portions of Cuba and the adjacent waters.

For the forecast, the Atlantic ridge will remain in place north of the area along 27N-28N through early Sat before weakening Sat night through Mon, as a frontal system moves slowly offshore of the SE U.S. Coast. The pressure gradient south of the ridge will sustain fresh to strong trade winds and moderate to rough seas in the south- central Caribbean through the forecast period, with highest winds and seas expected off the coast of Colombia. Pulsing winds at fresh to strong speeds and moderate to rough seas are expected in the Gulf of Honduras nightly through Sat, pulsing briefly to near gale-force Wed night and Thu night. Moderate to fresh E to SE winds are expected elsewhere across the northwestern Caribbean through Sun. Active showers and thunderstorms are expected across SW portions Wed through Fri as an upper-level trough digs into the area.

Atlantic Ocean

The Bermuda-Azores subtropical ridge is the dominant feature of interest across the tropical Atlantic, and is interrupted only by an old frontal trough extending into the region from 31N42W to 27N46W. The pressure gradient between this ridge and lower pressures in the Caribbean supports moderate to locally fresh trade winds S of 23N and W of 55W into the southeast Bahamas, with thermally enhanced strong trade winds and seas to 7 ft off northern Hispaniola. Moderate to locally fresh SW winds and moderate seas are occurring north of 27N and west of 72W. Meanwhile, moderate to locally fresh easterly winds and seas of 5-8 ft are found south of 21N and between 55W and 35W. In the far eastern Atlantic, moderate to fresh N to NE winds and seas of 5-7 ft prevail north of 15N and east of 25W. Elsewhere, moderate or weaker winds and moderate seas are prevalent.

For the forecast west of 55W, the Atlantic subtropical ridge will dominate the forecast area through Fri, then begin to weaken Fri night through the weekend as a weak cold front moves slowly offshore of the SE U.S coast. The related pressure gradient will maintain moderate to locally fresh trade winds south of 22N through Fri, diminishing slightly Fri night through Sat. Moderate to locally fresh SW winds offshore of northeast Florida to near 72W will expand eastward to near 65W through Wed night, as a weak frontal system moves across the southeastern U.S. The front is expected to move slowly offshore early Sat and stall offshore northeast Florida by Sun. Expect fresh to strong winds each afternoon through late evening across Atlantic waters near Puerto Rico and Hispaniola.

Posted 4 hours ago by NHC Forecaster Stripling