A Winter Storm Watch is now in effect for the entire area on Tuesday and Tuesday night, according to the National Weather Service Briefing, Jan. 27, 9 a.m. A Winter Storm Warning will likely be issued this afternoon for Tuesday.
All forms of winter precipitation will be possible Tuesday and Tuesday night beginning as a wintry mix, including ice accumulations and then transitioning to snow overnight in some locations. Snow accumulations are likely mainly SW Mississippi and Florida Parishes (East Baton Rouge, East Feliciana, Livingston, St. Helena, St. Tammany, Tangipahoa, Washington and Feliciana) by Wednesday morning.
Freezing rain and sleet are expected to start early Tuesday morning and persist most of the day, particularly over the Greater New Orleans area and the Mississippi Gulf Coast.
Estimated duration is as follows:
Baton Rouge: below freezing around 2 a.m. Tuesday; onset of winter precipitation around 6 a.m. Tuesday ending around daybreak Wednesday; above freezing around noon Thursday.
New Orleans: below freezing around 3 p.m. Tuesday; onset of sleet around 7 a.m. Tuesday, sleet/freezing rain after 3 p.m. ending around 9 a.m. Wednesday; above freezing around 10 a.m. Thursday.
Northshore: below freezing before dawn Tuesday; onset of winter precipitation around 6 a.m. Tuesday ending around 7 a.m. Wednesday; above freezing around noon Thursday.
A hard freeze duration of below freezing temperatures can be 48 to 60 hours from midnight Monday through noon Thursday. Moderate freeze expected Tuesday night/Wednesday morning with mid 20s to lower 30s. Hard freeze expected Wednesday night/Thursday morning with teens over much of the area and 20-25 south of tidal lakes.
These potential impacts are HIGHLY dependent on the strength of the upper disturbance and the amount of moisture and precipitation over any given location. This is a very fluid situation and all interests in the forecast area will need to monitor this situation very closely.
For more information, visit http://innovation.srh.noaa.gov/ertool/