Tropical Storm Sally Update 09/12/2020 2:00pm

Click HERE  for an update concerning Tropical Depression 19.

Changes from previous update: 

• TD19 is now forecast to reach hurricane strength

• Slower movement speed as it approaches the northern Gulf Coast

Overview:

• Tropical Depression 19 is forecast to move generally west northwestward this weekend over the eastern Gulf of Mexico. Thereafter, there is still some uncertainty in where Tropical Depression 19 will track and how much it will intensify.

Confidence:

• There is normal confidence in the track and below average confidence in the intensity forecast. The expected impacts could still change depending on its intensity.

Impacts:

Storm Surge:

• Using a Cat 1 MEOW moving from the NW at 5 mph
  • 8 to 12 feet above ground level for coastal areas from Mouth of the MS River to Biloxi, MS.
  • 4 to 8 feet above ground level for coastal areas from Biloxi, MS to MS/AL border and along the shores of Lake Pontchartrain and Maurepas.
  • 3 to 7 feet from Morgan City to the Mouth of the MS River.

• At a minimum, plan for several low-lying, coastal roads to become impassable due to flooding. 

• Some areas may become cut off or inaccessible 

• Storm surge levels will be highly dependent on the eventual track, size, and intensity of the system. There is a high degree of uncertainty in the forecast at this time and storm surge values are expected to change as forecast confidence increases.

Rainfall/Flooding:

• Rainfall of 3 to 8 inches is currently forecast. Locally higher or double amounts will be possible

• Expect ponding of water in low lying areas and some potential for localized flash flooding

• Possible slow movement of this system could create significant rainfall and associated flooding threats

Wind and tornado:

• Sustained tropical storm force winds with higher gusts are forecast with the strongest winds expected along the immediate coast.

• These winds could result in minor damage mainly to trees, power lines, and weaker structures. 

• A few tornadoes will be possible in the storm’s rain bands. Tornadoes in these situations are typically short-lived, but they move very quickly.

Additional Information and Resources:

NWS New Orleans Website: www.weather.gov/neworleans

NWS New Orleans DSS Website: http://www.weather.gov/lix/embrief

NWS New Orleans Tropical Page: https://www.weather.gov/srh/tropical?office=lix

River Gauges and Forecasts: http://water.weather.gov/ahps2/index.php?wfo=lix

NWS New Orleans Facebook: www.facebook.com/NWSNewOrleans

NWS New Orleans Twitter: https://twitter.com/NWSNewOrleans

Online Severe Weather Reporting: https://www.weather.gov/lix/submit_storm_report

National Hurricane Center Website: https://www.nhc.noaa.gov/

Next Update and Contact Information:

The next update will be sent by 5 PM CDT.