Weather
Maryland Winter Weather: How 1 Inch of Water Can Become 20 of Snow
Baltimore, MD – Winter storms across Maryland can produce dramatically different snowfall totals, even when communities receive nearly identical amounts of moisture. From Baltimore to Frederick, just
By Audrey Sloan · 2026-11-10T07:33:16.409Z
Baltimore, MD – Winter storms across Maryland can produce dramatically different snowfall totals, even when communities receive nearly identical amounts of moisture. From Baltimore to Frederick, just 1 inch of liquid precipitation can sometimes produce as little as 5 inches of heavy, wet snow or as much as 20 inches of lighter, fluffier snow.
The difference comes down to the snow to liquid ratio, a measurement that helps explain why snowfall accumulations can vary significantly during winter storms.
Why One Inch Can Produce 20 Inches of Snow
A commonly used forecasting guideline is the 10 to 1 ratio, meaning 1 inch of liquid water produces approximately 10 inches of snow.
However, actual snowfall ratios can vary considerably depending on atmospheric conditions.
Heavy, wet snow may have a ratio near 5 to 1, producing approximately 5 inches from 1 inch of liquid precipitation.
Colder, fluffier snow can sometimes reach a 20 to 1 ratio, producing approximately 20 inches from the same amount of moisture.
Baltimore and Frederick: Why Snowfall Can Differ
Baltimore's proximity to the Chesapeake Bay can introduce relatively warmer air during certain winter storms, increasing the potential for rain, mixed precipitation or wetter snow.
Frederick, located farther inland near the Catoctin Mountains, can experience colder conditions that sometimes favor greater snow accumulation.
Western Maryland's higher elevations may experience additional snowfall differences because of colder temperatures and mountainous terrain.
However, storm tracks, wind direction and atmospheric temperatures determine where the greatest snowfall develops.
What Maryland Residents Should Know
Wet, heavy snow can place additional stress on trees, power lines and rooftops, potentially increasing the risk of damage and power outages.
Lighter, fluffier snow may accumulate more deeply while containing less water per inch.
These differences can also affect road conditions along Interstate 70, Interstate 95 and Interstate 270, particularly when temperatures hover near freezing.
Understanding snow to liquid ratios helps explain why snowfall forecasts sometimes change even when expected precipitation amounts remain similar.
For Maryland residents, snowfall depth depends on more than how much moisture a storm brings. Temperature, wind and snow density can dramatically influence final accumulation totals.