Tropical Depression Nicholas is centered near 30.1N 91.9W at 16/0300 UTC or 10 nm SE of Lafayette Louisiana stationary. Estimated minimum central pressure is 1006 mb. Maximum sustained wind speed is 25 kt with gusts to 35 kt. A trailing trough is analyzed over the Gulf of Mexico and extends from 30N92W to 24N94W. The depression is currently nearly stationary over southern Louisiana, but is expected to gradually move northward over the next couple of days. The center of Nicholas may become ill-defined over the next couple of days as it evolves into a post-tropical remnant low with minimal thunderstorm activity near its center. Nicholas is expected to produce additional rainfall amounts of 2 to 5 inches across the central Gulf coast in southeastern Louisiana, southern Mississippi, southern Alabama and the Florida Panhandle through Friday, with isolated storm totals of 8 inches possible. Considerable flash flooding impacts, especially in urban areas, are possible across these regions. Widespread minor river flooding is expected, while scattered moderate river flooding is possible, across portions of southeastern Louisiana, southern Mississippi, southern Alabama, and the Florida Panhandle. The Weather Prediction Center is issuing advisories on Nicholas and they can be found at http://www.wpc.ncep.noaa.gov.
A surface trough extends from 31N73W to broad 1010 mb low pressure located near 29.3N74W to just N of Andros Island in the Bahamas. Most of the convective activity associated with this low is displaced to the E of the center and covers the area from 27N to 31N between 70W and 72W. Fresh to strong winds associated with this system are also noted to the E of the low center and mainly from 28N to 31N between 68W and 74W. An Air Force Reserve Hurricane Hunter aircraft investigating the system Wed afternoon reported that the circulation was disorganized and that the strongest winds were well to the east of the center. Environmental conditions are expected to become more conducive for development, and a tropical depression is still likely to form during the next day or two while the system moves north-northwestward to northward off the southeast U.S. Coast. Regardless of development, this system could bring high surf to portions of the southeast and mid- Atlantic U.S. Coasts later this week. This system has a high chance of tropical cyclone formation in the next 48 hours. Please read the latest Tropical Weather Outlook at www.hurricanes.gov for more details.
A tropical wave is in the Atlantic Ocean along 31W/32W from 03N to 17N, with 1011 mb low pressure along the wave near 11.5N31.5W, or more than 500 miles west-southwest of the Cabo Verde Islands, moving west at 15 to 20 kt. Showers and thunderstorms have changed little in organization in association with this area of low pressure. In addition, earlier satellite derived winds indicated the system also lacks a well-defined center. However, environmental conditions are still expected to remain conducive for development, and a tropical depression is likely to form during the next couple of days. This system is expected to move westward to west-northwestward across the tropical Atlantic during the next several days.. This system has a high chance of tropical cyclone formation in the next 48 hours. Please read the latest Tropical Weather Outlook at www.hurricanes.gov for more details.
Refer to the Special Features section above for details on a tropical wave and associated area of low pressure in the Atlantic Ocean along 31W/32W.
Another tropical wave is expected to emerge off of the west coast of Africa in a day or two. Thereafter, environmental conditions are forecast to be conducive for development while the system moves generally west-northwestward to northwestward over the far eastern Atlantic. Currently, a large cluster of moderate to isolated strong convection is affecting most of Senegal, The Gambia and the SW of Mauritania.
A tropical wave is in the Atlantic Ocean along 46W, from 04N to 17N, moving west at around 10 kt. Convection is limited near the wave axis.
A tropical wave is in the Caribbean Sea along 74W from 20N southward across Haiti to the Colombia-Venezuela border, moving west at 10 to 15 kt. The tropical wave combined with a mid to upper level low and daytime heating are helping to induce scattered showers and thunderstorms across the Greater Antilles and adjacent waters.
A tropical wave is over Central America along 87W from 18N southward across Honduras and western Nicaragua and into the eastern tropical Pacific Ocean, moving west at 10 to 15 kt. The tropical wave is helping to support scattered showers and thunderstorms over portions of northern Central America.
The monsoon trough emerges off the coast of Africa through Senegal near 15N17W to 1011 mb low pressure located near 11.5N31.5W to 11N40W to 07N52W. The ITCZ continues from 07N52W to the coast of Guyana near 08N59W. Aside from the convection mentioned above, scattered moderate convection is noted from 11N to 13N between 38W and 41W.
Gulf Of Mexico
The Weather Prediction Center is issuing advisories on Tropical Depression Nicholas, located over southern Louisiana. Refer to the Special Features section above for details.
As previously mentioned, a surface trough extends from the cyclonic circulation of Nicholas to near 24N94W. Gentle to moderate SE-S winds are noted east of the trough, with gentle to moderate NW-N winds west of the trough toward the Texas coast. Gentle to moderate easterly winds are seen just N of the Yucatan peninsula. Seas are 2 to 3 ft across the basin, except 3 to 5 ft over the north-central Gulf where part of the circulation of Nicholas remains. Isolated to scattered showers and thunderstorms are noted over the eastern Gulf.
For the forecast, Tropical Depression Nicholas inland north of the area is forecast to become a remnant low today. Conditions will continue to gradually improve offshore the Louisiana and upper Texas coasts. For the remainder of the week, gentle to moderate mainly southerly flow will dominate the Gulf waters under the influence of a ridge.
Refer to the Tropical Waves section above for details on a tropical wave moving across the Caribbean Sea.
Recent satellite derived wind data show moderate to fresh trades over the ABC Islands, near the entrance of the Gulf of Venezuela, and in the Gulf of Honduras, with mainly gentle to moderate winds elsewhere. Seas are 3-5 ft where the strongest winds are blowing with 1-3 ft elsewhere.
Showers and thunderstorms continue to flare-up over the Greater Antilles due to a combination of a tropical wave moving westward across the basin and an upper-level low currently located just S of eastern Cuba. A diffluent pattern aloft on the W side of the upper-level low is also helping to induce convection over most of Cuba and the NW Caribbean.
For the forecast, gentle to moderate winds will increase to moderate to fresh today, with strong winds pulsing during the overnights into the weekend offshore Colombia and in the Gulf of Honduras.
Refer to the Special Features section above for details on the disturbance situated northeast of the Bahamas, and the system in the eastern Atlantic. Both systems have a high chance of tropical cyclone formation through 48 hours.
A ridge dominates the Atlantic forecast waters E of 65W, with the main high pressure center of 1028 mb over the Azores. A surface trough continues to move westward across the tropical Atlantic and extends from 24N36W to 16N37W. Mainly low clouds and limited shower activity is noted near the trough axis. Scatterometer data depicted very well the wind shift associated with the trough axis. Moderate to fresh NE-E winds are noted near the northern end of the trough. Fresh to strong N-NE winds are present off the coasts of Morrocco and Mauritania, mainly east of 22W, due to the pressure gradient caused by the ridge and lower pressures over western Africa. Seas are in the 6 to 8 ft range across this area.
For the forecast, outside of the area of low pressure northeast of the Bahamas, high pressure will lead to gentle to moderate mainly easterly winds across the basin.
Posted 3 hours ago by NHC Forecaster Gr