Weather
Louisiana Snow: Why 20 Inches Can Start With Just 1 Inch
New Orleans, LA – Snow is uncommon across Louisiana, but winter weather science reveals a surprising possibility: Under the right atmospheric conditions, just 1 inch of liquid water can produce as muc
By Nora Whitfield · 2026-11-10T07:50:57.113Z
New Orleans, LA – Snow is uncommon across Louisiana, but winter weather science reveals a surprising possibility: Under the right atmospheric conditions, just 1 inch of liquid water can produce as much as 20 inches of fluffy snow.
That does not mean a major snowstorm is approaching. The comparison explains why snow depth can vary dramatically depending on temperature and the structure of snowflakes.
Why One Inch Can Produce 20 Inches of Snow
The snow to liquid ratio measures how much snow accumulates from a given amount of liquid water.
A commonly used guideline is 10 to 1, meaning 1 inch of liquid water produces approximately 10 inches of snow.
Heavy, wet snow may have a ratio closer to 5 to 1, producing about 5 inches from the same moisture.
Very light, fluffy snow can sometimes reach a 20 to 1 ratio, producing approximately 20 inches.
However, Louisiana's relatively mild winter climate makes these higher ratios less common.
New Orleans and Shreveport: Why Snowfall Can Differ
New Orleans, located near the Gulf of Mexico, is strongly influenced by relatively warm, moisture rich air.
That influence often keeps winter precipitation in liquid form, even when colder air moves into the region.
Shreveport, farther north in northwest Louisiana, can experience colder temperatures when Arctic air pushes south across the central United States.
During some winter weather events, northern Louisiana may experience snow or sleet while communities closer to the Gulf Coast receive rain.
However, unusual cold outbreaks can occasionally bring snow to southern Louisiana as well.
Temperatures throughout the atmosphere determine whether falling precipitation reaches the ground as rain, sleet, freezing rain or snow.
What Louisiana Residents Should Know
Freezing rain and sleet can create dangerous travel conditions even when little snow accumulates.
Bridges and elevated roadways are particularly vulnerable to icing during freezing temperatures.
Travel conditions can change quickly along Interstate 10, Interstate 20 and Interstate 49.
Cold weather can also threaten exposed plumbing, sensitive vegetation and infrastructure unaccustomed to prolonged freezing conditions.
Understanding snow to liquid ratios helps explain why snowfall amounts can differ even when storms carry similar moisture.
For Louisiana residents, winter weather impacts depend on more than precipitation totals. Temperature, storm tracks and precipitation type determine whether moisture becomes rain, ice or snow.