1. Heavy rainfall will impact areas across southern and central Louisiana, southern Mississippi, far southern Alabama, and the western Florida Panhandle through early Friday. Significant rainfall amounts are expected, potentially resulting in areas of life-threatening flash and urban flooding across these areas. Widespread minor to isolated moderate river flooding is also possible.

2. Storm surge inundation along the coasts of upper Texas and southwestern Louisiana will diminish tonight.

3. Wind gusts to tropical-storm force are possible for a few more hours along portion of the Louisiana and upper Texas coasts.

There are no coastal watches or warnings in effect.

Key messages for Nicholas can be found in the Tropical Cyclone Discussion under AWIPS header MIATCDAT4, WMO header WTNT44 KNHC and on the web at hurricanes.gov/graphics_at4.shtml?key_messages

RAINFALL: Nicholas is expected to produce additional rainfall amounts of 5 to 10 inches across portions of southern and central Louisiana, southern Mississippi, far southern Alabama, and the western Florida Panhandle through early Friday, with isolated storm totals of 20 inches possible from southern Louisiana to the far western Florida Panhandle. Life threatening flash flooding impacts, especially in urban areas, are possible across these regions. Widespread minor to isolated moderate river flooding is expected across portions of the upper Texas Gulf Coast and southern Louisiana and Mississippi. For the latest rainfall reports and wind gusts associated with Tropical Storm Nicholas see the companion storm summary at WBCSCCNS4 with the WMO header ACUS44KWBC or at the following link https://www.wpc.ncep.noaa.gov/discussions/nfdscc4.html

STORM SURGE: Storm surge levels will gradually subside into this evening. For information specific to your area, please see products issued by your local National Weather Service forecast office.

WIND: Wind gusts to tropical storm force are possible for a few more hours along the Louisiana and upper Texas coasts. These conditions should diminish later tonight and Wednesday morning.

TORNADOES: A tornado or two will be possible tonight through early morning from southeast Louisiana to southwest Alabama.

SURF: Swells generated by Nicholas will continue affecting portions of the northwest Gulf coast this evening and gradually subside tonight. These swells are likely to cause life threatening surf and rip current conditions. Please consult products from your local weather office.

At 1000 PM CDT (0300 UTC), the center of Tropical Depression Nicholas was located near latitude 30.0 North, longitude 94.1 West. The depression is moving toward the east northeast near 6 mph (9 km/h). A slow motion toward the east is expected tonight through Wednesday night, followed by a northward drift on Thursday. Maximum sustained winds are near 35 mph (55 km/h) with higher gusts. Continued gradual weakening is expected during the next couple of days, and Nicholas is forecast to degenerate into a remnant low Wednesday night or early Thursday. The minimum central pressure based on surface observations is 1004 mb (29.65 inches).

Satellite imagery, radar data, and surface observation indicate that the center of Nicholas is over the Beaumont/Port Arthur area of southeastern Texas. The cyclone is currently comprised of a large swirl of low- to mid-level clouds and showers, with a few patches of deep convection well removed from the center. The initial intensity of 30 kt is based on a combination of Doppler radar data and surface obs, and these winds are mainly over water to the southeast of the center. Nicholas should continue to weaken due to strong shear, dry air entrainment, and land interaction, and the cyclone is forecast to degenerate to a remnant low after 24 h and dissipate completely by 72 h. It should be noted that some of the track guidance models show enough south of east motion to bring the center back over the Gulf of Mexico in a day or two. However, even if this should occur the shear and dry air should prevent any re-development.

The initial motion is 060/5. While there is some spread in the guidance, it generally agrees on a slow eastward motion for 36 h or so, followed by a northward drift. The new forecast track has only minor changes from the previous track.

Although the winds associated with Nicholas are subsiding, due to the forecast slow motion, heavy rainfall and a significant flash flood risk will continue along the Gulf Coast for the next couple of days.

The is the last advisory on Nicholas issued by the National Hurricane Center. Future information on this system can be found in Public Advisories issued by the Weather Prediction Center beginning at 4 AM CDT, under AWIPS header TCPAT4, WMO header WTNT34 KWNH, and on the web at http://www.wpc.ncep.noaa.gov.